摘要 |
Dual phase steel sheet is made using a time/temperature cycle including a soak at about 1340-1425F and a hold at 850-920F, where the steel has the composition in weight percent, carbon: 0.02-0.20; aluminum: 0.010-0.150; titanium: 0.01 max; silicon: 0.5 max; phosphorous: 0.060 max; sulfur: 0.030 max; manganese: 1.5-2.40; chromium: 0.03-1.50; molybdenum: 0.03-1.50; with the provisos that the amounts of manganese, chromium and molybdenum have the relationship: Mn+6Cr+10Mo)=at least 3.5%. The sheet is preferably in the form of a strip treated in a continuous galvanizing or galvannealing line, and the product is predominantly ferrite and martensite.
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