FERRITE-AUSTENITE STAINLESS STEEL SHEET FOR STRUCTURAL MEMBERS EXCELLENT IN WORKABILITY AND IMPACT ABSORPTION CHARACTERISTICS AND PROCESS FOR THE PRODUCTION OF THE SHEET

摘要

This stainless steel sheet includes, in terms of mass %, C: 0.001 to 0.1%, N: 0.01 to 0.15%, Si: 0.01 to 2%, Mn: 0.1 to 10%, P: 0.05% or less, S: 0.01 % or less, Ni: 0.5 to 5%, Cr: 10 to 25%, and Cu: 0.5 to 5%, with a remainder being Fe and unavoidable impurities, and contains a ferrite phase as a main phase and 10% or more of an austenite phase, wherein a work-hardening rate in a strain range of up to 30% is 100MPa or more which is measured by a static tensile testing and a difference between static and dynamic stresses which occur when 10% of deformation is caused is 150MPa or more. This method for producing a stainless steel includes annealing a cold-rolled steel sheet under conditions where a holding temperature is set to be in a range of 950 to 1150°C and a cooling rate until 400°C is set to be in a range of 3°C/sec or higher.