Developments in Zinc Coatings

Benefiting Various End Use Applications MetalBulletin 20th Galvanizing & Coil Coating Conference, Istanbul September 2015 Esko Kauppinen, SSAB Europe

Contents ►About SSAB ►Alternative zinc coatings for innovative coated products ►Which coating properties give benefit to various end user needs ►Summary

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SSAB – global, highly-specialized steel company 3

SSAB in brief ►Nordic and US-based steel company with a global reach ►Leading producer of Advanced High Strength Steels (AHSS) and Quenched & Tempered steels (Q&T), standard strip, plate and tubular products as well as construction solutions ►About 17,000 employees in 50 countries ►Steel production facilities in Sweden, Finland and the US ►Annual steel production capacity of 8.8 million tonnes

►Structured across five divisions: • SSAB Special Steels, SSAB Europe, SSAB Americas, Tibnor, Ruukki Construction

►Listed on the Nasdaq OMX Stockholm and secondary listing on Nasdaq OMX Helsinki

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This is where we come from 1878 Domnarvets Järnverk, Borlänge

1914 Oxelösunds Järnverk AB

1940 Norrbottens Järnverk, Luleå 5

1956 IPSCO

1978 2007 Domnarvets SSAB acquires Järnverk, IPSCO Oxelösunds Järnverk AB and Norrbottens Järnverk become SSAB

1980 1960 1976 Tibnor becomes Rautaruukki Tibnor part of SSAB

2014 SSAB and Ruukki merge into one company

Steel production facilities in the Nordics & US 1

Luleå – employees 1,200

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Steel-making SSAB Europe

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Employees: 500 Heavy plate mill Scrap based EAF production R&D Centre

Raahe – employees 2,800 Steel-making, heavy plates and strip products, SSAB Europe

Hämeenlinna – employees 900 Coated strip products and tubes SSAB Europe

Montpelier, Iowa

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Mobile, Alabama Employees: 600 Heavy plate mill Scrap based EAF production Q&T lines

4 Borlänge – employees 2,100 Strip products SSAB Europe 1 2

5 Oxelösund – employees 2,300 Steel-making, heavy plates SSAB Special Steels

Strong globally and locally More than 50 countries of sales coverage

SSAB production sites Sales coverage

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Contents ►About SSAB ►Alternative zinc coatings for innovative coated products ►Which coating properties give benefit to various end user needs ►Summary

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WHY HDG? LIFE-CYCLE COST

Constant development since early 20th century Product name examples ”Magizinc, Magnelis, Corrender, Stroncoat, Superdyma” ”Galvalume” ”Galvannealed” ”Galfan” ”Alusi”

Source: Thomas Koll, 18th MetalBulletin Galvanizing & Coil coating conference

Alternative zinc coatings

Continuously and batch galvanized pure zinc (Z) Continuous

Lead containing zinc

Cross-section, batch

50…80 µm

Cross-section, contiuous 7…40 µm

Top view, lead-free zinc

Batch

►Continuously galvanized has the widest availability & applicability with uniform quality in cost effective package ►Batch galvanizing protects also the edges and gives the thickest coating layer

Alternative zinc coatings

Zinc alloy coatings Galfan (ZA) and ZnMg (ZM) with wide applicability Galfan

Top view, Galfan

ZnMg Top view, ZnMg

Cross-section Cross-section

► Galfan has excellent corrosion resistance – can double the time until red-rust vs. Zinc and beat corrosion resistance of ZnMg in real life corrosion environment ► Interest in ZnMg has risen in Europe aided by superior results in widely used accelerated corrosion tests

Alternative zinc coatings

Zinc alloy coatings Galvannealed (ZF) and (AZ) for selected applications Galvannealed

AZ Top view, AZ

Top & SEM view, ZF SEM cross-section

► Galvannealed is the standard material for car manufacturers in Japan – thanks to easy processability (galling, weldability) and paintability vs. regular zinc (Z) − Big market penetration never seen in European automotive market

► AZ is widely used in the US & Asia as CC substrate but seen as niche in Europe

CORROSION Resistance to corrosion is usually the 1st argument for or against a metallic coating – How do we measure it?

Corrosion categories for zinc CORROSION ENVIRONMENT

FIELD STATION FOR TESTING

CORROSION CATEGORY

Rural

Ryda (Sweden)

C2

Urban

Stockholm (Sweden)

C2

Marine

Bohus Malmön (Sweden) Brest (France)

C3

Industrial

Jianjing (China)

C4

Laboratory environment

-

C5

C4 occasionally exists in Europe in marine or industrial environment, but it is uncommon

Cut edge protection Five years of outdoor exposure in Jiangjing, China, corrosion category C4, show no difference in cut edge protection between galvanized, Galfan and ZnAlMg coatings.

Galvanized Z275

Galfan ZA255

ZnAlMg ZM275

Thickness loss p.a. for Galfan and ZnMg is similar – approximately 1.3-2.5 times smaller than HDG

Accelerated salt spray tests (ISO 9227, ASTM B 117) It’s widely known among corrosion scientists that no correlation exists between performance in salt spray and outdoor conditions…why?

A CONSTANT HIGH HUMIDITY

A CONSTANT HIGH TEMPERATURE

VERY HIGH SALT CONCENTRATION

In reality, there is a great variation. Testing conditions alter the chemical reactions and the corrosion products.

Accelerated salt spray tests – Zinc vs. ZnMg

Source: European Comission, AUTOCOAT-Project Final Report, ref. EUR 26323

Seeing is believing… ZnMgAl coatings are up to 20 times better than galvanized coating in salt spray tests.

Appearance of a galvanized panel after testing in salt spray.

Appearance of a galvanized lamp pole after many years of outdoor use.

Vast difference in surface appearence when comparing samples exposed to salt spray test and outdoor exposure due to different chemical reactions.

Appearance of 50 years old galvanized roof in finnish countryside

Quotes

”The well-known ASTM B-117 salt spray test provides a comparison of cold rolled and galvanized steel within several hundred hours. Unfortunately, the salt spray test is unable to predict the well-known superior corrosion resistance of galvanized relative to uncoated rolled steel sheet.” Towsend, HE. ”Development of an Improved Laboratory Corrosion Test by the Automotive and Steel Industries”, Proceedings of the 4th Annual ESD Advanced Coating Conference, Dearborn, USA, 1994

Contents ►About SSAB ►Alternative zinc coatings for innovative coated products ►Which coating properties give benefit to various end user needs ►Summary

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Automotive

Alternative zinc coatings for Automotive ►Technical development and changing customer needs have revealed different demand drivers for alternative zinc coatings over decades ►Corrosion protection ►Cost efficiency

►Rise of Electro-galvanized

►Rise of HDG

►Availability ►Productivity

►Rise of Galvannealed in Asia Source: Nippon Steel News No.308. 10/2003

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ZnMg using now mainly same arguments as ► Galvannealed in Asia in the 80’s

Construction and infrastructure construction

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Sener – Solar thermal power solutions PRODUCT •

Structural parts for a 50MW solar heating plant with cylindrical parabolic collectors

CHALLENGE • • • •

Old structures were mainly assembled on site More pre-fabrication Reduced weight Good corrosion resistance

SOLUTION •

High Strength Steel + Galfan

BENEFITS • • • • •

Excellent corrosion resistance Improved precision in steel parts due to Lower weight More efficient production and logistics Technical education of personnel and support in product development from SSAB engineers

Araj– Silos with highly polished finish PRODUCT •

Silos for grain storage and drying facilities

CHALLENGE • • • •

Develop larger silos Find a reliable long-term supplier Silos need to be resistant to severe weather conditions Surface appearance need to be uniform in color and gloss

SOLUTION •

High Strength Steel + Galfan

BENEFITS • • • •

Excellent corrosion resistance Increased strength of the silo shells Nice shiny surface of the silos Increased capacity of the silo

Light engineering

Gazdevice – Galfan saves time PRODUCT •

Gas meter used to calculate the consumption of natural gas for private use

CHALLENGE • • •

Reduce costs by substituting electro galvanizing at remote production site with process with ready coated steel Heavy duty deep drawing and bending involved Good corrosion resistance needed

SOLUTION •

Substitute electro galvanizing of parts made of cold rolled steel with Galfan deep drawing grade

BENEFITS • • • • •

Excellent corrosion resistance Advanced deep drawing without micro cracks in the metal coating Shorter lead time since parts were not send away for galvanizing Improved control of qualite since everything is made in-house Reduce costs

Bobicompany – A more durable letterbox PRODUCT •

Letterboxes

CHALLENGE • • • •

Good corrosion resistance required Smooth, high quality appearance Welding a bottleneck in production Production • Maintenance of welding electrodes • Grinding time consuming and generated dust and noise

SOLUTION •

Change from galvanized to Galvannealed

BENEFITS • • • •

Improved surface appearance Improved corrosion resistance Earlier, welding tips were changed every third box, now series of 1.0001.500 boxes can be produced without need for change No need of grinding which result in less dust and noise in production

Batch Galvanizing Substitution

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Batch galvanizing process steps

PACKING

LOADING

TRANSPORT

UNPACKING

BATCH GALVANIZING

QUALITY CONTROL

PACKING

LOADING

TRANSPORT BACK

UNLOADING

UNPACKING

Substitution in infrastructure ►One main argument for batch galvanizing is the cut edge protection ►Important to notice that after longer exposure time the main failure mode of continuously galvanized is linear degradation ► The Finnish Transport Agency has approved following coatings to be used in poles for traffic signs − Batch galvanized 55 µm Zinc − Continuous galvanized 42 µm Zinc (Z600) − Aluzinc 25 µm (AZ185)

Z600

Batch galvanized

Contents ►About SSAB ►Alternative zinc coatings for innovative coated products ►Which coating properties give benefit to various end user needs ►Summary

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Improved competitive advantage with Galfan Longer life of products

Excellent corrosion resistance compared to zinc coated steel

Possibilities to make advanced forming

Excellent forming properties compared to zinc coated steel

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More attractive appearance of painted products - Best painted surface

Excellent paintability

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Longer life of painted products

Very good corrosion resistance as painted

v

Reduced welding costs

Longer electrode life and low galling on electrodes Reduced or no need for improving appearence of welds before painting

v

Reduced laser cutting costs

Good laser cutting properties

v

Improved competitive advantage with Galvannealed

More efficient forming and punching

No need for cleaning of tools due to galling on tool surface

Improved competitive advantage by substitution Improving competitive advantage by substituting batch galvanizing with Galfan or thick zinc layer, Z450 or Z600

Reduced production costs

Continuous galvanized steel shortens production lead-time due to reduced number of production steps

Reduced material costs

Continuous galvanizing is a more cost efficient production method compared batch galvanizing and total cost is lower

Long life of products

Thick zinc coating, Z450, Z600 or Galfan coatings give a very good corrosion resistance in normal environments

Rust Never Sleeps

• Salt spray testing cannot predict the corrosion rate in outdoor environments. • Only by testing in real conditions relevant and reliable corrosion data can be obtained.

SUMMARY ► Variety of zinc alloy coatings exist on market – often with overlapping technical properties and demand drivers ► So far zinc alloy coatings (ZM, ZA, ZF, AZ) exist only on niche markets − Geocraphic, application or technological ► Zinc magnesium is the first possible candidate in decades trying to break away from the niche ”stamp” 38

LIFE-CYCLE COST