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Jawaharlal Nehru
IS 1918 (1966): Methods of physical tests for foundry sands [MTD 14: Foundry]
“!ान $ एक न' भारत का +नम-ण” Satyanarayan Gangaram Pitroda
“Invent a New India Using Knowledge”
“!ान एक ऐसा खजाना > जो कभी च0राया नहB जा सकता ह” है” ह Bhartṛhari—Nītiśatakam
“Knowledge is such a treasure which cannot be stolen”
IS : 1918 - 1966
Indian Standard METHODS OF PHYSICAL TESTS FOR FOUNDRY SANDS ( Th ir d Repr in t AP RIL 1997 )
UDC 621.742 : 620.1
0 Copyright 1966 BURE AU MANAK
Gr 7
OF
BH AVAN,
INDIAN
STANDARDS
9 BAH ADUR SH AH NE W DE LH I 110002
ZAF AR
MARG
December 1966
IS: 1918-1966
Indian
Standard
METHODS OF PHYSICAL TESTS FOR FOUNDRY SANDS Fou nd ry Sectional
Com m ittee,
SMDC
17
Rcfitzsmting
Chairman
In per son a l ca pa cit y
SERI N. G. CE AKRABABTI
( 3/D, Nandy Strsrt, Calcutta-29)
Members Th e In dia n Ir on & St eel Co Lt d, Ca lcu t t a SH RI H . R. BADYA~ DE P . VASUDE VAN (Alt er n a t e ) Cooper E n gin eer in g Lt d, Sa t a r a Roa d SBRI B. N. BALIQA H in du st a n Ma ch in e Tools Lt d. Ba n ga lor e SE E I D. N. BANE RJ E E SH RI K. NAQF .SH A RAO ( Alternate ) Th e In dia n P lu m ba go Co, Bom ba y SBRI NANUBH AI H . BH ATT SRBI SURE SH N. BH ATT ( Alternate ) In dia n F ou n dr y Associa t ion , Ca lcu t t a SH RI S. C. BISWAS SH RI M. K. RAO ( Alternate) Th e J a y E n gin eer in g Wor ks Lt d, Ca lcu t t a SERI P . K. CH ATTE RJ E E E n gin eer in g Associa t ion of In dia , Ca lcu t t a SERI S. N. CH AUDH UE I SH RI B. N. BALI~A ( Alternate ) Bu r n & Co Lt d, H owa r h ; ond In dia n E n gin eer in g SH RI S. K. DAM Associa t ion , Ca lcu t t a SRRI B. SE N ( .4lternate) Mu ka n d Ir on & St eel Wor ks Lt d, Bom ba y SHXI D. H. DATE Dir ect or a t e Gen er a l of Tech n ica l Developm en t , DB P . DAYAL Min ist r y of In du st r y a n d Su pply SHRI B. P . SINHA (Alternate) J yot i Lt d, Ba r oda SH BI A. S. DE ~AI SE RI N. SE N ( Alternate) DIRE CTORATE OF F LE E T Na va l H ea dqu a r t er s MAINTE NANCE , NE W DE LH I Th e Ta t a Ir on & St eel Co Lt d, J a m sh ed UT SH BI M. S. DU A In spect ion Win g, Dir ect or a t e Gen er a l o P Su pplies St SH BI M. L. DUTT ROY Disposa ls ( Min ist r y of In du st r y & Su pply ) &OF S. N. IYE NGAR U n icor n P r iva t e Lt d, Ma dr a s SH BI V. R. IYE B Th e Br it a n n ia E n gin eer in g Co Lt d, Tit a gh u r SHE1 S. J OE BI Ku m a r dh u bi E n gin eer in g Wor ks Lt d, Ca lcu t t a SH BI J . T. KANA~ABAJ ( Alt er n a .r e\1 DIRE CTOR RE SE ABUE Min ist r y of Ra ilwa ys J OINT ( M & C ), RE SE AROH , DE SIGNS & STANDABDS OBQANIZATION, CH ITTAE ANJ AN CH E MIE T ik ME TALLUBOI~T, CH ITTABANJ AN LoaomoTms Woags, CH ITTAB- J AN ( Altern& ) WOBICS MANAQE B ( MANUF AOTWINO ), CH ITTABANJ AN LOCOMOTIVE WOBKB, CH ITTIBANJ AN ( Altarn& ) ( Contimrcd on paage2 )
INDIAN MANAK
STANDARDS BH AVAN,
9
BAH ADUR
INSTITUTION SHAH
NEW DELHI 110002
ZAFAR
MARG
IS : 1 9 1 8- 1 9 6 6 ( Confinuedfrom~ugc1 ) Representing
Members
H in du st a n St eel Lt d, Bh ila i S HRI M. N. KH ANNA SH RI R. R. SABAN ( Alt er n a t e) La bor a t or y ( CSIR ), Na t ion a l Met a llu r gica l SE RI R. M. KBISH NAN J a m sh edpu r Bh a r t ia E lect r ic St eel Co Lt d, Ca lcu t t a Da 0. P . LUTH E B N ew P r ecision ( In dia ) P r iva t e Lt d, Dewa s SH RI B. V. MAE ABALE Th e Mysor e Ir on & St eel Lt d, Bh a dr a va t i SH RI K. H . MAH ADE VAP P A , SH RI M. LIN~AIAE ( Alfer n a t e ) Ma ch in er y Ma n u fa ct u r er s Cor por a t ion Lt d, Ca lcu t t a S HRI AMAL MITRA SH RI H . S. P AUL ( Aller n a t e ) Bom ba y Met a l & Alloys Ma n u fa ct u r in g Co P vt Lt d, SH RI N. J . MODY Bom ba y In dia n N on -F er r ou s Met a ls Ma n u fa ct u r er s’ Associa Sa a r T. N. D. P ILLAI t ion , Ca lcu t t a SH RI D. P . J AIN ( Alt er n a t e) Th e Ta t a E n gin eer in g & Locom ot ive Co Lt d, SH RI H . C. P RADH AN J a m sh edpu r P ion eer E qu ipm en t Co P vt Lt d, Bom ba y SH RI K. S. S. VA~AN SH RI P . B. H . J H AVE BI ( Alt er n a t e ) Th e In dia n In st it u t e of Met a ls, Ca lcu t t a DB P . VASUDE VAN The Institute of Indian Foundrymen, Ca lcu t t a SHRI ARJAN VABWAN I SH RI S. GUH A ( Alt er n a t e ) Dir ect or Gen er a l, IS1 ( Ex-o&o Member ) SH RI B. S. KRISH NAMACH AR, Dir ect or (St r u t & Met ) Secr et a r y SH RI R. K. SRIVAE TAVA Depu t y Dir ect or
Panel for Methods SH RI R. M. KRISH NAN
ofPhysical
(Met a ls),
IS1
Tests for Foundry Na t ion a l Met a llu r gica l sh edpu r
Sands,
SMD C
La bor a t or y
17 : P 1
( CSIR j, J a m
IS I 1 9 1 8 - 1 9 6 6 CONTENTS PAGE
0. 1.
FOREWORD S COPE
... ...
SECT I ON 2. 3. 4. ‘5 .
28.
.. . ...
. .. ..
4 4
. .. ... ... ...
... ... ... ...
4 5 5 6
GEN ERA L
2 M ET H OD OF PH Y SI CA L T ES’I S FOR FOU N DRY M OU L DI N G, SA N DS
DETERMINATION OF MOIS TURE CONTENT ... DETERMINATION OF CLAY CONTENT . . . ... ... DETERMINATION OF GRAIN FINENES S. . . ... ... DETEZWINATION OF GRAIN S HAPE DETERMINATION OF PERMEABILITY , . . ... DETERMINATION o F TENS ILE S TRENGTH ... DETERMINATION OF COMPRES S IONS TRENGTH ... ... DETERMINATION OF S HEAR S TRENGTH DETERMINATION OF BULK DENS ITY . . . ... DETERMINATION OF GREEN MOULD S URFACE HARDNES S DETERMINATION OF FLOWABILITY ... . .. DETERMINATION OF S HATTER INDEX . . . . .. ... DETERMINATION OF S INTERING POINT
SECT I ON 19. 20. 21. 22. 23. 24. 25. 26. 27.
I
..* ... TERMINOLOGY ... ... S AMPLING ... PREPARATION OF FOUNDRY S AND FOR TES TING PREPARATION OF S TANDARD TES T S PECIMEN
SECT I ON 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18.
... ...
,.. .. .
3
M ET H ODS FOU N DRY
OF PH Y SI CA L CORE SA N DS
7 8 9 12 13 14 16 17 18 18 19 19 19
T EST S FOR
DETERMINATION OF MOIS TURE CONTENT ... DETERMINATION OF CLAY CONTENT . . . ... DETERMINATION OF GRAIN FINENES S .._ . .. DETERMINATION OF GRAIN S HAPE ... ... DETERMINATION OF PERMEABILITY . . . ... DETERMINATION OF S TRENGTH ... ... ... DETERMINATIONOF BULK DENS ITY . . . DETERMINATION OF BAKED S CRATCH HARDNES S . . . DETERMINATION OF GAS GENERATED IN A CORE ... BAKING ... ... ... DETERMINATION OF S INTERING POINT ...
3
... .. . ... .,. ... ... .. . ... ... .. . . .. ... ...
. .. . .. . .. ... .. . .*. ... . .. DUR .ING ... ...
22. 22 22 22 22 23 27 27 27 28
IS : 1 9 1 8 - 1 9 6 6
Indian
Standard
METHODS OF PHYSICAL TESTS FOR FOUNDRY SANDS 0.
F OREWORD
0 .1 This Ind ian Stand ard w as ad op ted by the Ind ian Stand ard s Jnstitu tion on 8 Au gu st 1966, after the d raft finalized by the Fou nd ry Sectional Com m ittee had been ap p roved by the Stru ctu ral and Metals Division Cou ncil. 0.2 This stand ard ou tlines basic principles of physical tests for fou nd ry sand s. Any stand ard sand testing equ ip m ent shall be u sed for testing fou nd ry sand s. ‘The d etailed p recau tions su pplied bv the m anu factu rer w ith the testing equ ip m ent shall be follow ed along w ith the p roced u res specified in this stand ard . The test specim en to be u sed shall be one of the tw o recom m end ed in this stand ard as applicable to the equ ip m ent. 0.3 This stand ard keeps in view the m anu factu ring and trad e p ractices While follow ed in the cou ntry in this field . tance has been d erived from the follow ing: DIN
p rep arm
this stand ard
52401 Exam ination of clayfree and claybond ed m ou ld ing in the loose and in the’com p ressed m oist and green state.
assis4nd s
Deu t-
scher N orm enau sschu ss. Fou nd ry sand hand book. 1963. Ed 7. Am erican Fou nd rym en’s Society, Illinois, USA. 0.4 For the p u rp ose of d ecid ing w hether a particu lar requ irem ent of this stand ard is com p lied w ith, the final value, observed or calcu lated , exp ressing the resu lt of a test or analysis, shall be rou nd ed off in accord ance w ith The nu m ber of significant p laces retained - in the rou nd ed off IS : 2-1960*.
value shou ld be the sam e as that of the specified value in this stand ard .
1 . SCOPE 1 .1 This stand ard p rescribes the m ethod s of tests evalu ate their p rop erties u nd er stand ard cond itions. SECT I ON
I
for
fou nd ry
sand s
to
GEN ERA L
2 . TERMIN OLOGY 2 .1 For the p u rp ose of this stand ard , the term ‘ Found ry Mou ld ing Sand ’ shall inclu d e high-silica sand , natu ral m ou ld ing sand , synthetic m ou ld ing *Ru les for rou nd ing off numerical
values
(revised). 4
IS : 1918 - 1966 sand m ixtu res, and reclaim ed sand placed in heap s on the fou nd ry floor for reuse. 2.2 The term ‘ Core Sand ’ shall cover sand that is su itable for m akm g cores, u su ally low in clay su bstance. 3. SAMPEIN G 3.1 Representative sam ples shall be d raw n accord ing sam pling given in IS : 1811-1961*. 4. PREPARATION
OF FOUN DRY
of Natural
of
S AN D F OR TES TIN G
4.1 P re p a ra tio n o f Hig h -S ilic a S a n d -The with 3.1 shall be used without any processing. 4.2 Preparation
to the schem e
Motllding
samples
in accordance
Sand
4.2.1 Tempering by HandDry abou t Z-kg sam ple of sand for one hou r at 105” to 110°C. Sp read the sand over a large area in a thin layer S Othat After allow ing the sand to cool all m oistu re is expelled in the given t ime. d ow n to room tem p eratu re, m easu re the qu antity of w ater need ed to give the d esired m oistu re content ( in term s of p ercent w eight of tem p ered m ix ), ad d ing little extra w ater ( u su ally from O-25 to 1-O p ercent ) to allow for evap oration. Sp read the sand on a sm ooth, flat, d ry, non-absorbent su rface in a layer abou t 25 m m thick. Sprinkle a small qu antity of the w ater from the m easu red qu antity evenly over the sand and w ork the sand grad u ally. Sp read again the sand into a thin layer and rep eat the above op erations, ad d ing m ore w ater. Rep eat the process u ntil all the w ater has been thorou ghly d istribu ted in the sand . There shou ld be no d ry lu m p s or other evid ence of u neven tem p ering. 4.2.2 Alt ernat e Met hod of Tempering by Hand-In case sand has a low er m oistu re content than d esired , it need not be d ried before tem p ering. Ad d su fficient w ater to bring the sand to the d esired m oistu re content. In case the sand has a higher m oistu re content than d esired , the sand shall be partially d ried , allow ed to cool and then tem p ered w ith su fficient w ater to bring the m oistu re to the d esired value. 4.2.3 Tempering by Mechanical Mixing - Dry abou t 2-kg sam ple of sand as given in 4.2.1. Place the d ried sand in the laboratory m ixer and ad d su fficient w ater to p rod u ce the d esired moist ure content p lu s an ad d itional am ou nt to allow for evap oration d u ring m ixing. Water shou ld be ad d ed grad u ally w ithin 30 second s w hile the m ixer is op erating. Total m ixing tim e shou ld be 5 m inu tes. N OTE-An y one method of tempering shall be follow ed throughout to prepare sand mixture of same or different moisture contents during the course of an investigation for evaluating a sand sample. *Methods of sampling foundry sands.
5
IS : 1918 - 1966 4.3 P re p a ra tio n o f S y n th e tic a lly B o n d e d S a n d Mix tu re - Test s&m pies of synthetically bond ed sand m ixtu re shall be p rep ared in a m echanicai m ixer. Dry abou t 2 kg of sand for one hou r at 105” to 110°C. Sp read the sand over a large area in a thin layer so that all m oistu re is expelled in the given tim e. After d ryin g and cooling to room tem p eratu re, w eigh the correct am ou nts of sand or sand s, and bond or bond s, as u sed in the Place the d ried sand and then the d ried bond ing m atefou nd ry m ixtu res. Place the cover on the m ixer, start the m ixer and m ix rials, in the m ixer. Follow ing the tw o-m inu te m ixing p eriod , allow tw o for tw o m inu tes. m inu tes for d u st to settle before rem oving the m ixer cover. Ad d the required am ou nt of w ater grad u ally w ithin 30 second s to give the required m oistu re p ercentage p lu s su fficient ad d itional w ater to allow for evap oratitan d u ring m ixing. Mix for a period of 5 m inu tes. Rem ove the sand from the m ixer as quickly as possible. Allow sam ples to stand in an air-tight container for tw o hou rs before testing. N OTE - Variation in physical properties w ith moisture content shall be determined by giving small increments to w ater content (say 0.5 to 1.0 percent ).
5. P REP ARATION 5.1 Ap p a ra tu s -
OF S TAN D ARD Stand ard
5.2 Te s t S p e c im e n aild 50.8 m m d iam eter shall be u sed .
TES T S P ECIMEN
sand ram m er w ith accessories.
Cylind rical test specim en of 50.8 f O-03 m m height ( or of 50 -& O-3 m m height and 50 m m d iam eter j
5.3 P ro c e d u re -We ig h su fficient qu antity of tem p ered sand m ixtu re to m ake, w hen ram m ed , a specim en of required height. Place the sand careAfter levelling the sand in the container, fully in the specim en container. gently low er the ram m ing head into the specim en container, u ntil it is su p p orted by the sand . Slow ly raise the ram m er w eight by hand or by cam to the full height of the specim en and let it fall. Rep eat tw ice, m aking a total of 3 ram s to get the stand ard test specim en. 5.3.1 For sand s w hich d o not possess su fficient bond strength to p erm it hand ling, a circular d rier p late shall be placed on top of a stripping p ost. After the specim en is strip p ed from the container, it shall be hand led by lifting the d rier p late. 5.3.2 For preparing specim ens of low bond stretigth, ram m ing is d one in a split specim en tu be. The specim en, after it is ram m ed , is rem oved from the split specim en tu be by op ening the tu be and allow ing the specim en to rest on a d rier p late. 6
IS : 1918 SECT I ON
2
l
1966
M ET H OD OF PH Y SI CA L T EST S FOR FOU N DRY M OU L DI N G S AN D S
6 . D ETERMIN ATION
OF MOIS TU RE
CON TEN T
6.1 D ire c t We ig h t Me th o d * 6.1.1 Proced u re - Weigh accu rately abou t 100 g cf sam ple of sand in a tared covered porcelain d ish. Dry it in a u niform ly heated oven betw een 105” and 1lO’C for abou t one hou r. Cool to room tem p eratu re and w eigh. Rep eat the process of d rying and cooling till constant w eight is attained . 6.1.2
Calcu late
the p ercentage m oistu re by the follow ing form u la: Moistu re, p ercent = $
x 100
w here A = loss of w eight of the sand sam ple in g on heating,
and
B = w eight in g of the sand sam ple taken.
6.1.3 Make the d eterm ination on three separate sam ples and take the average of three test results as the m oistu re content of the sand . 6.2 Ca lc iu m
Ca rbid e .Me th o d
6.2.1 Apparatu s -
Sp eed y m oistu re tester.
6.2.2 Proced u re - Weigh accu rately abou t 6 g ofsam p le of sand and place it in the cap of the instru m ent. Take a m easu re of calciu m carbid e and place in the shaker. Place the cap and the shaker in the horizontal p osition, ad ju st stirru p , fasten cap to shaker w ith set screw on stirru p and finally shake the contents. Read m oistu re content on d ial gau ge keeping the ap p aratu s in a horizontal p osition. Make d eterm inations on three separate sam ples and take the average of three results as the m oistu re content of the sand m ixtu re. NOTE- The sand m ixtu re and calcium carbide should not come in contact w ith each other until the cap of the moisture tester is securely in place. 6.3
Co n tro l Me th o d s - For control tests, m oistu re in fou nd ry sand s m ay be d eterm ined by d irect w eight m ethod , calciu m carbid e m ethod or by any other m ethod ( su ch as d ielectric typ e m oistu re m eters ) w hich w ill d u plicate the accu racy of results obtained by the d irect w eight m ethod .
*This method is applicable for all sand mixtures except those containing rial ( other than w ater) or oxidisable materials such as core oils or both. mixture, calcium carbide method ( see 6.2 ) shall be used.
7
volatile mateFor such sand
Is : 1918 - 1966 7. DETERMINATION
OF CLAY CONTENT
7.1 Apparatus
-An electric rapid agitator equ ip p ed w ith vertical baffles or a rotating sand w asher shall be u sed .
7.2 Reagent
7.2.1 Sodium Hydroxide Solu tion - Dissolve 30 g of sod iu m hyd roxid e in d istilled w ater and d ilu te to a total volu m e of one litre. 7.3 Procedure
7.3.1 General -Take a 50-g representative sand sam ple. Sp read it over a large area in thin layer and d ry it for one hou r at 105’ to 110°C so that all m oistu re is expelled . Weigh the d ried sam ple and plad e it in an rapid agitator equ ip p ed w ith vertical baffles or a rotating sand elect1 w asher. Ad d 475 m l of d istilled w ater (@H 7.0 d eionized or d em ineralized w ater ) &d 25 m l of sod iu m hyd roxid e solu tion at room tem p eratu re. ( If a rotating w asher is u sed , place the cover on the Stir for five m inu tes. jar, and the jar in a m achine m aking abou t 60 rev/ m in in su ch a m anner Operate the m achine as to allow the jar to be op ened at each revolu tion. for one hou r. Then rem ove the jar from the m achine, u nseal the cover and w ash the ad hering sand into the jar, ) Wash sand from the stirrer into the jar and fill the jar w ith d istilled w ater to a height of 150 m m above the bottom of the jar and in su ch a m anner that the contents are w ell stirred . Allow to settle for 10 m inu tes and then syp hon off the w ater to a d ep th of exactly 125 m m below the level to w hich it had been filled , leaving a m inim u m d ep th of 25 m m of w ater in the bottom of the jar. Ad d d istilled w ater, again filling the jar to the 150 m m height, stirring the sed im ent at the bottom . After settling for the second tim e for 10 m inu tes, again sip hon off 125 m m of the w ater. Ad d w ater again filling to 150 m m height, stirring the sed im ent at the bottom . After settlm g exactly for 5 m inu tes, sip hon off 125 m m of the w ater. Rep eat the process of five m inu tes stand &g. and siphoning u ntil the w ater is clear to a d ep th of 125 m m at the en of five-m inu te p eriod . By this m ethod , the m &&al Thie w hich fails t6 settfe at a rate of 25. m m p er m inu te is rem oved . is stand ard clay grad e m atter and includ es all grains of 20 m icrons or ‘less Dry and w eigh the rem aining grains. The d ifference in d iam eter. betw een the w eight of the d ried grains and that of the original 50-g sam ple represents clay content. NOT= - Certain varieties of sand m ay rew ire longer agitation to liberate p rop erly the clay from the sand grains. Incomplete clay remova! may be checked microscopically.
7.3.1.1 Calcu late
clay
content
d nd sand
p ortion
form u lae:Clay content, p ercent = w 1 w
w , x 100 1
8
by ..the follow ing
iS : 1918 - 1966 W Sand p ortion, p ercent = 3w
x100 1
w here WI = w eight in g of the d ried sand sam ple taken for the test, and w , = w eight in g of the d ried sand p ortion ( free from clay ). 7.3.2 Synthetic Sand Mixture - The p roced u re in accord ance w ith 7.3.1 hall be slightly changed for sand m ixtu res containing coal d u st, coal resid ues, and bind er resid ues. As given in 7.3.1, 50 g of fou nd ry sand is w ashed after d rying. In the cou rse of w ashing op eration a p art of the coal d u st and similar su bstances is rem oved , the rem aind er being p art of the sand p ortion. The w ashed sand p ortion is heated in a porcelain crucible to 750°C for bu rning the coal and the coal-free sand is w eighed . The heating loss, equal to the total coal content, is d eterm ined by heating to 750°C and w eighing a separate sam ple of u nw ashed , d ried fou nd ry sand . The heating tim e shou ld be su fficient for com p lete com bu stion of the coal contained in the sand . The clay su bstance shall be the d ifference betw een the tru e sand p ortion ( w ashed and heated sam ple ) p lu s coal p ortion ( of u nw ashed and heated sam ple ), and the total qu antity of u nw ashed d ried sand . 7.3.2.1 If cereal bind ers ( especially d extrin ) are present in the sand , a prelim inary w ash shall be m ad e w ithou t ad d ing sod iu m hyd roxid e to the d istilled w ater. After stirring and allow ing the sand to settle for 10 m inu tes, sip hon off the w ater. Then p roceed as u nd er 7.3.1. 7.3.2.2 A sand m ixtu re containing cem ent cannot be w ashed free of cem ent by the m ethod given u nd er 7.3.1. The cem ent shall be rem oved from the sand grains by ad d ing 25 m l of d ilu te hyd rochloric acid ( 1 t 1 by volu m e ) instead of sod iu m hyd roxid e, taking su itable p recau tions against acid attacking the agitating ap p aratu s. 8. DETERMINATION
OF GRAIN
FINENESS
8.1 General -The p ercentage of grain sizes shall be d eterm ined by sieving the d ried clay-free sand . Sifting tim e shall be at least 15 m inu tes and the test sieves u sed shall be 3*35-m m , l-70-m m , 850-m icron, 600+m icron, 425-m icron, 300-m icron, 2 1P-m icron, 150.m icron, 106-m icron, 75-m icron and 53-m icron IS Sieves. 8.2 Ap p aratu s
-
A set of Ind ian Stand ard s
Sieves (see IS : 460-1962’
).
-Sieve 50-g of representative sam ple throu gh 11 sieves 8.3 Proced u re ind icated u nd er 8.1 starting w ith the coarse sieve. Weigh ou t the sand retained on each sieve and the p an m aterial ind ivid ually and p u t d ow n as p ercent of the d ried u nw ashed sand . *Specification for test sieves ( revised ) .
9
LS : 1 9 1 8 - 1 9 6 6 8 .4 Evalu at io n
o f Fin e n e s s
o f S an d
8 .4 .1 Size-Frequency Curve - The size-frequ ency cu rve shall be obtained by p lotting the p ercent of sand retained on each sieve (see Fig. 1 ).
100 90 ul %
W
60
i 5 70 ._
5 0
Y
60
z 50 L f 40 ?I u 30 K a 20 10
I
850
IS
600
SlEVE
N OTE-Va lu e s
425
300
ar
212
OESIGNATIONS
150 106
75
53
IN MICRONS
a lo n g a bs c is s aa re p lo tte don lo g s c a le .
F ro . 1 CU RVESCON S TRU CTEDFROM SI EV E AN ALYS ISOF Tw o F OU N D RY S AN D S TO S HOW COMP ARIS ONOF S IZE-F REQU EN CYAN D CU MU LATIVE Cu RVES 8.4.2 Cumulative Curve -The cu m u lative cu rve p oints shall ind icate the p ercentage of particles larger than the sieve size represented by that p oint ( SCGFig. 1 ). The cu m u lative cu rve is alw ays sm ooth, w hereas size frequ ency cu rve m ay not alw ays be a broken line connecting the d ifferent sieve p oints. If a sand is taken on specification, tw o cu m u lative curves m ay be d raw n show ing the lim iting values for each sieve. Then, if the cu rve of the sand being tested falls betw een these tw o cnrves it shall’be satisfactory. Finally, d ata for slit and clay m ay be p lotted as a p art af the sam e grap h. Sieves that retain little m aterial m ay be elim inated or ad d itional ones m ay be ad d ed w ithou t d istorting the cu rve. If there are
10
IS : 1 9 1 8 - 1 8 6 6 fau lty sieves these shall be ind icated by a break at the sam e p oint in the cu rve w hen d ifferent sam ples of the sam e sand arc sieved . ind ex to the sorting or d istribu tion of the 8.4.3 Sorting Coe# cient -A n grains in a sand sam ple shall be obtained from the sorting coefficient, $, d efined by the follow ing form u la:
w here Q1 is the size in m icrons sand crosses the 25 percent microns where the curve
where the cumulative curve for a retained line and Qs is the size in crosses 75 p ercent retained . Sorting
coefficient is a rapid m ethod of ind icating This is also a m easu re of the d istribu tion.
the slope of the cu rve.
The range of d istribu tion nu m bers shall be from 1-O for particles of u niform size, su ch as ball bearings to a m axim u m of abou t 10-O. Washed and grad ed sand s shall range from l-14 to l-40 w hile natu rally bond ed sand s are u su ally betw een I.40 and 2.50. 8.4.4 Grain Fineness N umber - It is ap p roxim ately 2.54 tim es the nu m her of m eshes p er centim etre of that sieve w hich w ou ld allow to pass the sam ple if its grains w ere of a u niform size, that is, the average of the sizes It is ap p roxim ately p rop ortional to the su rface of grain in the sam ple. area p er u nit w eight of a sand , exclusive of clay. 8.4.4.1 Calculation ofjneness number - Exp ress the w eight in gram s of variou s sizes accord ing to the p roced u re given u nd er 8.3 as p ercentage ot the original 50-g sam ple. Mu ltiply them by the m ultipliers as given in Table 1. Ad d the p rod u cts and d ivid e the total by the su m of the percenThe resu lt shall be the grain fineness nu m ber. ages of sand grains. TABLE
1
IS
MULTIPLIER
FOR GRAIN
FINENESS
NUMBER
MTJLTIPIJSB
SIEVE
3 5 10 20 30 40 50 70 100 140 200 300
3*35-mm l-70-mm 850-micron 600-micron 425-micron 300-micron 2 12-micron 150-micron 106-micron 75-micron 53-micron Pan 11
’
IS : 1918.1966 9. DETERMINATION
OF GRAIN
SHAPE
-A low p ow er stereoscop ic m icroscop e 9.1 Apparatus reflected light and giving m agnifications of 30 x to 60 x .
w orking
w ith
9.2 Procedure - The grain shap e shall be d eterm ined by the m icroscop ic exam ination of a small p ortions of the grain size fractions from all the sieves and the p an at m agnifications of 30 x to 60 x . 9.2.1 The grain shapes to be d istinguished are rou nd ed , su bangu lar, Id entification for grain shap e angu lar and splintered as show n in Fig. 2. shall be based on the p red om inant grain shap e of the largest fraction ( by w eight ) of sand .
Upper Low er Upper Low er
Left Left Right Right
-
Angular Sand Grains Subangular Sand Grains Rounded Sand Grains Compound and Splintered Sand Grains
Fro. 2
SAND GRAINS 12
IS : 1 9 1 8 - 1 9 6 6 1 0 . DETERMIN ATION
OF PERMEABILITY
10.0 Perm eability is d efined as that physical p rop erty of the m ou ld ed m ass of sand m ixtu re w hich allow s gas to pass throu gh it. It is num erically equal to the volu m e of air in millilitres that w ill pass p er m inu te u nd er a pressu re of 1 gf/ em s throu gh a specim en of 1 em s in cross-sectional area and 1 cm high. 1 0 .1 De t e rm in at io n
perm eabilitv su bstance.
o f Bas e
Pe rm e abilit y
-
of p acked d ry sand grains containing
Base perm eability is the no clay or other bond ing
IO.1 .I A pparatus 1 0 .1 .l .l Standard permeability meter 1 0 .1 .1 .2 Stop-watch
10.1.1.3 Standard sand rammer along w ith the stand ard specim en container and special screens to be kep t at each end of the specimen to hold the bond free sand in p osition in the specim en tu be. The screen shall be sau cer shap ed , one pressed w ithin the other, the sau cer being of such d iam eter as to ju st fit into the stand ard s ecim en container. The outer screen shall be of m etal and p erforated w it*r: at least 100 holes at the rate of 16 holes of I.6 m m d iam eter p er squ are centim etre. the sam ple for its clay content in accordance 10.1.2 Procedure -W ash # w ith the m ethod given u nd er 7.3 and d ry the sand grains thorou ghly at 105” to 110%. Place a base perm eability screen, w ith sid es of the cu p u p w ard , in the bottom of the stand ard specim en container. Place su fficient qu antity of d ried sand in the specim en container to p rod u ce the stand ard sand test specim en. Place the second base perm eabilitv screen, w ith sid es of the cu p d ow nw ard , on top of the sand in the specim en container. R~w n the specim en in accord ance w ith the m ethod given in 5.3 bbt d o not rem ove the specim en from the container. Place the specim en co ntainer w ith the specim en in the m ercu ry seal of the perm eability ap p aratu s. Find ou t the tim e required for exactly 2 000 m l of air to pass throu gh the After the pressu re has becom e stead y, read the pressu re on the specim en. pressu re ind icator and record in gf/ cm s. 10.1.2.1 Calcu late the base perm eability nu m ber (P) of the sand from the follow ing form u la: vxh p =----Pxaxt w here v 7 volu m e of air in m l passed throu gh the specim en, h = height of the test specim en in cm , p = pressu re of the air in gf/ cm 2, a = cross-sectional area of the test specim en in cm 2, and t = tim e in m inu tes. 13
IS t 1918 - 1966 10.1.2.2 Test three speLlmens individually. The base permeability shall be the average of three tests. If the test result of one of the test specimens varies more than 10 percent from the average of three, this result shall be discarded and another specimen tested. 10.2 D e te rm in a tio n o f Gre e n P e rm e a bility - The green permeability of foundry moulding sand is the permeability of a moulded mass o f sand In other w ords, it is the permeability in its moist or tempered condition. of a naturally or synthetically-bonded foundry moulding sand mixture w hich (a) has been mixed and tempered experimentally in the laboratory or (b) has been mixed and tempered for use in the foundry, 10.2.1
A pjmatus -
Same as described in 10.1.1.
10.2.2 Test Specimen shall be used.
The
standard
test. specimen specified under 5
the standard test specimen 10.2.3 Procedure -Ram container and follow the procedure as given in 10.1.2. 10.3 D e te rm in a tio n
in
a
specimen
o f D ry P e rm e a bility
10.3.0 D ry permeability is defined as the permeability of a moulded mass of sand, containing clay or binders, w hich has been completely dried at 105” to 110°C. 10.3.1
A@mztw -
Same as described in 10.1.1.
10.3.1.1 Special type of split specimen container used for ramming test specimens ( see 5.3.2 ). 10.3.1.2 Standard d rie r 10.3.1.3 Special permeability machine attachment for the determination of dry permeability. 10.3.2 Test @ecimen - The standard test specimen specified under 5 shall be used after drying at 105” to 110°C in the drier for a period of 2 hours and cooling to room temperature in a desiccator. 10.3.3 Procedure - Using the split specimen container to hold the dried specimen, determine the dry permeability as in 10.1.2. 11. D ETERMIN ATION
OF TEN S ILE
8TREN GTII
11.0 The tensile strength of a moulding sand mixture is the maximum tensile stress w hich the sand mixture k capable of sustaining w hen prepared, rammed and tested according to standard procedures. 11.1 D etermi~tlon of W l,ensila ltrengtb -Green tensne strength is the tensile strength of a foundry sand mixture in the moist or tempered condition.
14
IS : 1 9 1 8- 1 9 6 6 1 1 .1 .1 A@m z t u ~ -Dead w eight typ e of universal sand strength testing m achine or spring typ e of sand strength testing m achine. 1 1 .1 .2 Test Q ecimen - A specially d esigned specim en tu be shall be u sed for m aking the stand ard test specim en (see 5.2 ). It shall be a tw op art tu be d esigned so that the specim en m ay rem ain in the tu be d u ring testing and the tw o halves of the tu be read ily separate ap p roxim ately at the m id d le of the specim en w hen it fails ( see Fig. 3 ). 11.1.2.1 In preparing the test specim en the specim en tu be is placed on its ped estal cap and the tu be carefully filled w ith the correct w erght of sand to be tested . The specim en tu be and ped estal cap are then placed d irectly beneath the ram m er and ram m ed accord ing to the p roced u re given u nd er 5.3.
FIG. 3
S PECIMEN TUBE FOR DETERMIN IN GGREEN AND TENS ILE S TRENGTH OF FOUNDRY S ANDS
1 1 .1 .3 Procedure - Place the ram m ed specim en contained in the specim en tu be in the specim en tu be hold er and hold firmly by m eans of tw o clam p screw s. Ap p lV a u niform load along the axis of stand ard test specim en at the rate not exceed ing I.5 f O-5 gf/ m m * p er m inu te u ntil the specim en breaks. Record . the breaking Ioad in gram s and caIcu late the
15
tensile strength in kgf/ cm & by ru p tu re section.
d ivid ing
the
breaking
load
w ith
area
of
11.1.3.1 An average of three tensile tests shall be taken. If the test resu lt of one of the three varies m ore than 10 p ercent from the average of three, this resu lt shall be d iscard ed and another sp ecim en tested . 11.2 D e te rm iu a tio n o f D ry Te n s ile S tre n g th - Dry tensile strength is the tensile strength of a fou nd ry sand m ixtu re w hich has been d ried at 105” to 110°C and cooled to room tem p eratu re in a d esiccator. 11.2.1 d rier.
A pparatus
-
Sam e is d escribed
in 11 .l.l
together
w ith a stand ard
test sp ecim en contained in the 11.2.2 Test Qecimen - The stand ard sp ecim en tu be (see 11.1.2 and 11.1.2.1 ) shall be Gsed after d rying at 105” to 1 10% in a d rier for a p eriod of 2 hou rs or u ntil d ry, and cooling to room tem p eratu re. 11.2.3 Procedure - Test the d ried sp ecim en in the sp ecim en tu be as u nd er 11.1.3. In this test the rate of load ing shall not exceed 10.0 f l-5 gf/ m m 2 p er m inu te. 12. D ETERMIN ATION
OF COMP RES S ION
S TREN GTH
12.1 D e te rm izs a tio n o f Gre e n Co m p re s s io n S tre n g th - The greecom p ression strength of a fou nd ry m ou ld ing sand is the m axim u m com p ressive stress in gf/ m m 2 w hich the sand in u nbaked cond ition is cap able of w ithstand ing. 12.1.1 A pparatus - Dead w eight typ e of u niversal sand m achine or sp ring typ e of sand strength testing m achine. 12.1.2 u sed .
Test Specimen -
The stand ard
test sp ecim en
strength
sp ecified
testim p
in 5 shall br.
12.1.3 Procedure - Ram a stand ard test sp ecim en and strip it fron, the sp ecim en container. Place the test sp ecim en in the com p ression m achine in su ch a m anner that the top of the sp ecim en as ram m ed in the sp ecim en container rests against the u p p er head of the m achine. Ap p ly a u niform load against the p lane faces ‘of the sp ecim en so that the force is axial at a rate of 2 1 f 4 gf/ m m z p er m inu te u ntil the sp ecim en breaks. Record the load at ru p tu re. 12.1.3.1 form u la:-
Calcu late
Green
the green
com p ression
com p ression
strength,
strength
from
the follow ing
gf/ m m s =$
w here F = load at ru p tu re in gf, and A = cross-sectional area of the test sp ecim en 16
in mm*.
IS : 1918 - 1966 12.1.3.2 Test three specim ens ind ivid ually. The com pressive strength shall be the average of three tests. If the test resu lt of one of the specim ens varies by m ore than 10 p ercent, from the average of the three this resu lt shall be d iscard ed and another specim en tested . 12.2 D e te rm in a tio n o f D ry a n d B a k e d Co m p re s s io n S tre n g th - Dry com p ression strength is the m axim u m com pressive stress in gf/ m m * w hich a d ry sand m ixtu re is cap able of d eveloping. In case the test specim en has been baked at a specified tem p eratu re above 1 lO”C, the m axim u m com pressive stress in gf/ m m a d eveloped is know n as ‘baked com p ression strength ’ 12.2.1 12.2.2 u sed .
A j~aratus -
Same as specified in 12.1.1.
Test SjM cimen -
The stand ard test specim en specified in 5 shall be
12.2.2.1 Drying - When tile sand m ou ld s, the specim en shall lated oven and allow ed to cool to the specim en after it has reached
test is applied to sand s for u se in green be d ried on a flat, rigid p late in a ventiroom tem p eratu re in a d esiccator. Test the room tem p eratu re.
12.2.2.2 Baking - When the test is applied to sand s u sed for d ry sand m ou ld ing or to other m ixtu res w hich w ou ld norm ally be baked at a tem p eratu re higher than 1 lo’%, a baking tem p eratu re and tim e w hich is su itable for that particu lar m ixtu re shou ld be u sed . 12.2.3 Proced u re-The stand ard test specim en after rem oval from the specim en container shall be d ried or baked and cooled as specified in 12.2.2. The specim en shou ld be placed in the ap p aratu s w ith the sam e sid e against the com p ression head w hich w as u p p erm ost in the specim en container d u ring ram m ing. Ap p ly a u niform load against the plain su rfaces of the specim en 50 that the force is axial at a rate of 100 f 15 gf/ m m a p er m inu te, u ntil the specim en breaks. Record the load at ru p tu re. Calcu late the d ry or baked com p ression strength as u nd er 12.1.3.1. 13. D ETERMIN ATION
OF S HEAR
S TREN GTH
13.1 D e te rm in a tio n o f Gre e n S h e a r S tre n g th The green shear strength of sand is the m axim u m shear stress w hich a tem p ered sand m ixtu re is cap able of d eveloping. 13.1.1 A fiparatus strength attachm ent. 13.1.2 be used.
Universal stand ard sand testing m achine
Test Specimen -
The stand ard
test specim en
specified
w $h
shear
in 5 shall
13.1.3 Procedure-Ram a stand ard test specim en and strip from thr specim en container. Place the specim en betw een the shear head s of the 17
IS t 1918 - 1966 m achine in su ch a w ay that the load is applied along a line throu gh its axis. Ap p ly a u niform load to the d iam etrically op p osite halves of the tw o plain sqfaces of the specim en at the. rate of 17 .f 4 gf/ m m a p er m inu te. Record the breaking load in kg and c&d late the shear strength in gf/ m m 2 by d i ‘id ing the breaking load by area of ru p tu re section. 1“s .1.3.I Test three specim ens ind ivid ually. The sheer strength shall be the average of three tests. If the test resu lt of one of the specim ens varied m ore than 10 p ercent, from the average of the three, this resu lt shall be :d iscard ed and another specim en tested . 13.2 D e te rm in a tio n o f D ry S h e a r S tre n g th - The m ethod given in 13.1 shall be em p loyed for the d eterm ination of d ry shear strength, excep t that the test specim en shall be d ried at 105’ to 110°C for 2 hou rs or u ntil d ried , and allow ed to cool in a d esiccator to room tem p eratu re before testing. 14. D ETERMIN ATION 14.1 D e te rm in a tio n
OF B U LK D EN S ITY
o f B u lk D e n s ity B e fo re Co m p re s s io n
14.1.1 Procedure -Take 500 g ,of tem p ered sand m ixtu re as p rep ared u nd er 4 and allow it to fall in a one-litre m easu ring cylind er throu gh a p erforated d isc rotating slow ly at the 1 000 m l m ark. After the w hole sand has d rop p ed into the m easu ring flask, even ou t the sand su rface by slightly pressing w ith the p erforated d isc. The ratio of the m ass of the sand to the volu m e occu p ied by it w ill represent the bu lk d ensity before com p ression in gram s p er millilitre ( g/ m l ). 14.2 D e te rm in a tio n 14.2.1 Apparat us 14.2.2 u sed .
o f B u lk D e n s ity a fte r Co m p re s s io n Stand ard
Test S’ecimen -
ram m er and physical balance.
The stand ard
test specim en specified in 5 shall be
14.2.3 Procedure - Ram a stand ard test specim en as given in 5.3. ,Weigh it in a balance and also calcu late. its volu m e from its d im ensions. The ratio of the w eight of the specim en to tne volu m e w ill give the bu lk d ensity after com p ression in g/ m l. 15. .D ETERMIN ATION
OF GREEN MOU LD
S U RF ACE HARD N ES S
15.0 Green m ou ld su rface hard ness is the &stance offered by the su rface of a green sand m ou ld to p enetration .by a load ed p lu nger. I .l Ap p aratnsI 1X1.1 u sed .
Stand ard
Test SpeGimn -
m ou ld su rface hard ness tester.
The stand ard test specim en specified in 5 shall be
18
IS : 1918 - 1966 15.1.2 Procedure- B&g the unloaded plunger of the tester in contact w ith the mould surface. Apply the load to the plunger and read the hard ness number, on the graduated dial of the testing apparatus. N OTE -The test is performed on standard test specimen pxpared as given in 5 or on the mould itself. The test should be performed immediately after the specimen is stripped from the tube or the pattern is w ithdraw n from the mould.
16. D ETERMIN ATION
OF F LOWAB ILITY
16.0 In general the term ‘ flow ability’ refers to the movement grains w hen they are subjected to moulding forces. 16.1 Ap p a ra tu s -Standard flow ability meter. 16.2 Te s t S p e c im e n used.
sand rammer
together
of sand
w ith the standard
The standard test specimen specified in 5 shall be
16.3 Procedure - Read the percent flow ability on the dial of the flow ability meter after. the fifth drop of the ramming w eight. The stem of the flow ability meter rests against the top of the plunger of the rammer and registers the movement of the rammer plunger betw een the fourth and fifth drops as percentage flow ability. 16.3.1 Test three specimens individually. The flow ability number shalt be the average of three tests. If the test result of one of the specimens varies more than 10 percent from the average of three, this result shall be dircarded and another specimen tested. 17. D ETERMIN ATION 17.1 Te s t S p eci m en used.
OF S HATTER
T h e standard test specimen specified in 5 shall be
17.2 P ro c e d u re -Ra m a standard ance w ith the method given in 5.3 1 830 mm. Collect the portion of the The percent w eight retained shall be 18. D ETERMIN ATION
IN D EX
test specimen by 10 blow s in accordand allow it to fall from a height of sand retained on. 12-mm IS Sieve. the shatter index.
OF S IN TERIN G
P OIN T
18.1 D e te rm in a tio n o f S in te ria g P o in t o f Hig h -S ilic a S a n d - Sintering point of high-silica sand shall be determined in accordance w ith the method given under 3 of IS : 1526-1962+. *Methods of sampling and physical tests for refractory materiala.
19
ls:1918-1966
18.2 Determination
of Sintering Point of Foundry
Sand
Mixtures
X8.2.1 Afibaratus 18.2.1.1 Porcelain combustion boats 15 mm width. 18.2.1.2
Electric furnace-
of 75 to 90 mm length
with a testing temperature
and 10 to
of at least 1 500°C.
boat 18.2.2 Procedure - Loosely filI the sand sample in the combustion and place the boat in the hot zone of the electric furnace. When temperature has reached 1 000°C keep the temperature constant for at least 3 Take out the boat from the furnace, cool and observe whether minutes. the sintering of the sand grain has started. If not sintered, replace the combustion boat in the furnace and continue the test with temperature increments of 50°C till sintering occurs. Keep the combustion boat at each particular temperature for at least 3 minutes. After cooling, examine the sand sample for sintering by scraping or visual examination with a magnifier or microscope. 18.2.3 Determination of ‘A’ Sintering Point of Foundry Sand Mixtures - ‘A sintering point is the lowest temperature at which the ribbon used in the sintering test makes a ‘V’ when lifted off the sand specimen. NOTE -Th e ‘V’ determination sands w ith very low dry atnngth.
18.2.3.1 Apparatus -Standard sintering
is applicable
to practically
equipment
all types of sands except
for the deten&ation
of ‘A’
point,
standard test specimen 18.2.3.2 TdSt specimen -The and dried for at least one hour at 105” to 110%.
as specified
in 5
18.2.3.3 Procedure - Place the sand specimen in position in the sintering apparatus under the platinum ribbon heater. Centre the specimen between the platinum ribbon holder terminals and place the platinum ribbon in contact with the rounded surface of the sand specimen, allowing 170-g load to be ap lied to the ribbon. Sight the optical pyrometer on the central part of the pPatinum ribbon and adjust it to read the desired tempeAllow for the emissivity of platinum as given in Table 2. Pass an rature. electfic current through the platinum ribbon and adjust the variable resiatance%so that the brightness of the platinum ribbon matches the brightness of the. filament or dot in the optical pyrometer, which has been set at the desired temperature. Heat to rquired temperature in about 30 seconds and start a stop-watch and allow the heated ribbon to remain in contact with the specimen to cool for exactly 15 seconds. Lift up the ribbon holder and ribbon MXI observe whether the ribbon adheres to the sand specimen and makes a ‘V? when it is lifted. Rotate the specimen about 50 mm to a fresh surface and again place the platinum ribbon in contact with the speciinen. All adhermg material should be removed from the ribbon by scraping or dissolving in hydrofluoric acid after each individual 20
IS t 1 9 1 8 - 1 9 6 6 d eterm ination. If the ribbon d id not m ake a ‘V’ rep eat the above p roced u re, this tim e increasing the.tru e tem p eratu re by abou t 23 d eg. This corresp ond s to an increase in the observed tem p eratu re of abou t 22 d eg. The actu al either valu es shou ld be taken from Table 2. Rep eat the above p roced u re by increasing or d ecreasing the tru e tem p eratu re by increm ents or d ecrem ents of 25 d eg, u ntil ribbon d oes not m ake a d efinite ‘ V ’ at one tem p eraThe low est tru e tem p eratu re tu re, bu t d oes at the next higher tem p eratu re. at w hich the p latinu m ribbon m akes a d efinite ‘V’ w hen lifted off the sand sp ecim en 15 second s after the 4lm inu te heating p eriod is the 10 > 5, up to 10
Least Count g 1 0.5
> 1, up to 5
0.1
> 0.5, up to 1 > 0.1, up to 0.5
0.05 0.01
> 0.05, up to 0.1
0.005
< 0.05
0.001
(MTD 14) Reprography Unit, BIS, New Delhi, India
