Introduction Contents 1 2 3 11 12 29 31 Cross-sectional structure of the coating layer Al 34 Zn 34 35 Coating layer Steel sheet Zn2Mg 37 Enlarged photo of eutectic structure Coating layer : Fine ternary eutectic structure of Zn, Al, and Zn2Mg 1 Nisshin Steel Quality Products
Features Nisshin Steel Quality Products 2
Typical applications 3 Nisshin Steel Quality Products Nisshin Steel Quality Products 4
5 Nisshin Steel Quality Products Nisshin Steel Quality Products 6
7 Nisshin Steel Quality Products Nisshin Steel Quality Products 8
Mounting strap Mounting strap 9 Nisshin Steel Quality Products Nisshin Steel Quality Products 10
Manufacturing process Cooling tower Tension leveler Cooling section Horizontal radiant tube furnace Preheating furnace Oiler Upright direct-fired reducing furnace Post-treatment Shipment Exit-side looper Tension reel Payoff reel Pre-treatment 2-stand skin-pass mill 4-pot galvanizing bath To galvanizing equipment Welder Entry-side looper From pickling and cold-rolling equipment Galvanizing pot HCGL annealing furnace (upright direct-fired reducing furnace) HCGL annealing furnace (horizontal radiant tube furnace) 11 Nisshin Steel Quality Products
Quality characteristics Thin Zinc-Aluminum based film containing Mg. Coating layer Steel base Coating layer Corrosion of coating layer suppressed Excellent Corrosion resistance Initial exposure period (up to several weeks) Coating layer Substrate The exposed cut end of substrate is oxidized Subjected to rain and condensation Intermediate exposure period (beyond several weeks) Substrate The thin zinc-based film containing Mg on the coating layer flows over the cut end Long exposure period (after more than a year) Substrate Gradually changes to gray and eventually gray-black C (Thickness: 2.3mm, coating weight : 130/130g/m 2, chromate treatment : 50mg/m 2 ) Appearance of cut end after outdoor exposure test (Thickness : 3.2mm, coating weight : 150/150g/m 2, post-treatment : chromate 50mg/m 2 ) Nisshin Steel Quality Products 12
Lapse of time before occurrence of red rust (hours) 14,000 12,000 10,000 8,000 6,000 4,000 2,000 Red rust occurrence after salt spray test 0 ZAM 55%Al-Zn alloy coated steel Zn-5%Al alloy coated steel Galvanized steel 100 200 300 400 500 600 One-side coating weight (g/m 2 ) Appearances of specimens after salt spray test (Coating weight : 90g/m 2 (one side), untreated) Appearances of cut ends after salt spray test (Thickness : 3.2mm, coating weight : 120/120g/m 2, untreated) 13 Nisshin Steel Quality Products
Appearances of cut end sections after atmospheric exposure test (Industrial area : Sakai-city, Osaka-prefecture, Japan, Coating mass : 90/90g/m 2, chromate treatment 50mg/m 2 ) Evaluation position Projection welding Nisshin Steel Quality Products 14
Appearances of 1t bend processed part after salt spray test (1t, 180bending, thickness : 3.2mm, 120/120g/m 2, untreated) Appearances of 1t bend processed part after 90-day exposure tests (1t 1mm, 180bending, thickness : 3.2mm, 120/120g/m 2, untreated) 15 Nisshin Steel Quality Products
Corrosion loss (g/m 2 /day) Corrosion loss of three types of coated steel sheets in ammonia water Zn 55Al-Zn Discolaration (No red rust) Steel base corrosion (red rust) Test piece Test solution Nisshin Steel Quality Products 16
Corrosion loss (g/m 2 /day) Corrosion loss of four coated steel sheets in acidic and alkaline aqueous solutions ZAM 55%Al-Zn alloy coated steel Zn-5%Al alloy coated steel Galvanized steel 17 Nisshin Steel Quality Products
Nisshin Steel Quality Products 18
Surface appearances (flat part) of two types of coated steel sheets in salt spray test Surface appearances (cut ends) of two types of coated steel sheets in salt spray test 19 Nisshin Steel Quality Products
Corrosion loss of ZAM and post hot dip galvanized products in sulfur dioxide tests 700 Corrosion loss (g/m 2 ) 600 500 400 300 200 ZAM (Thickness 2.3mm, 90g/m 2 (one side)) Post hot dip galvanized product (HDZ55) (Thickness 2.3mm, 560g/m 2 (one side)) Occurrence of red rust 100 0 100 200 300 400 500 Test duration (hr) Appearances after 450 hours of sulfur dioxide test Corrosion loss (g/m 2 ) Corrosion loss of ZAM and post hot dip galvanized products in acid rain simulated combined-cycle corrosion test 180 160 ZAM (Thickness 2.3mm, 90g/m 2 (one side)) 140 Post hot dip galvanized product (HDZ55) (Thickness 2.3mm, 560g/m 2 (one side)) 120 100 80 60 40 20 0 0 200 400 600 cycle Nisshin Steel Quality Products 20
Appearances of coated steel sheets after salt-spray test After combined-cycle corrosion test 21 Nisshin Steel Quality Products
Scratch resistance of various types of coated steel sheets (scratch test) 18 Radius of tip of test needle : 0.05mm 16 14 Scratch load (gf) 12 10 8 6 4 2 0 ZAM 55%Al-Zn alloy coated steel Zn-5%Al alloy coated steel Galvanized steel Nisshin Steel Quality Products 22
23 Nisshin Steel Quality Products
Type Al coated steel sheet 30/30 55%Al-Zn alloy coated steel sheet50/50 Zn-5%Al alloy coated steel sheet75/75 ZAM 60/60 Galvanized steel sheet 40/40 Galvannealed steel sheet 40/40 Welding current ka Lack of strength OptimumExpulsion Pick-up Cold-rolled steel sheet nugget diameter4tt : thickness, pressure applied : 200kgf, electrification time :12cycles, thickness : 0.8mm, electrode shape : CF type, 6mm in diameter Example of proper welding conditions for various steel sheets (Figures in parentheses are the coating weight in g/m 2 ) Nisshin Steel Quality Products 24
Appearances of surface of touch-up painted part after combined-cycle corrosion test (Thickness : 2.3mm, coating weight : 85g/m 2 (one side)) Surface appearances of touch-up painted ends after combinedcycle corrosion test (Thickness : 2.3mm, coating weight : 85g/m 2 (one side)) 25 Nisshin Steel Quality Products
/ / / Appearances of surface after testing painted material Material tested : untreated material for each coated steel sheets Painting pre-treatment : zinc phosphate treatment Paint : Acrylic resin, 1coat (No.1), Super Lac F-50 made by Nippon Paint Nisshin Steel Quality Products 26
Appearances of processed part after 24 hours of humidity cabinet test (BBT) (90bend, bending radius : 1mm) Appearances after 72 hours of salt spray test (SST) 27 Nisshin Steel Quality Products
Surface appearance Surface appearances after 72 hour salt spray test (JIS Z2371) Surface appearance in salt spray test of flat part Top surface Bent section Side Nisshin Steel Quality Products 28
Certificates We have obtainedarchitecture execution technology and technology examination certificate (examination certification No.0004)at the Building Center of Japan (BCJ), a certification body of the then-minister of Construction andconstruction technology examination certificate (construction technology examination certificate No.0122) of the Civil Engineering Research Center. These awards attest that ZAM can replace post hot dip galvanized products having at least the equivalent corrosion resistance with only about one-sixth of the coating weight of post hot dip galvanized products,andcan be used in fields that could not have been properly serviced by conventional post hot dip galvanized products in terms of corrosion resistance. Also, acquisition of the Building Center of JapanConstruction technology examination certificate (building technology)(bcj Examination certificate 138) certifies that the chromium-free treatments (ZC treatment and ZG treatment), which are ZAM after-treatments, have white-rust resistance that is at least equivalent to that of highcorrosion-resistance chromate treatment (A treatment), without using chromium. 29 Nisshin Steel Quality Products
Nisshin Steel Quality Products 30
Standards 31 Nisshin Steel Quality Products
Nisshin Steel Quality Products 32
MSM - ZAM product symbol Base sheet classification (H : hot, C : cold) Type and application Surface finish Post-treatment Coating weight labeling symbol 33 Nisshin Steel Quality Products
Available sizes Cold-rolled substrate 1,325 1,250 Hot-rolled substrate 1,325 Width (mm) 1,050 Width (mm) 600 600 0.25 0.8 2.3 0.35 Thickness (mm) 1.6 6.0 Thickness (mm) Examples of processed products Processing example at the customer Nisshin Steel Quality Products 34
Quality and quantity tables 35 Nisshin Steel Quality Products
Nisshin Steel Quality Products 36
Precautions in use 37 Nisshin Steel Quality Products
38 Nisshin Steel Quality Products
SPCC SPHC ZAM