LOAD PREDICTION MODEL OF 17-PERCENT-CR-7- PERCENT-NI STAINLESS-STEEL IN COLD-ROLLING

The load prediction model of 17%Cr-7%Ni stainless steel in cold rollin g has been developed. In this model, the flow stress equations include d deformation-induced martensitic transformation and the mathematical model of rolling load based on the approximate theory of Bland & Ford are considered. The volume fraction of martensite by ferrite scope was modified by X-ray diffraction method. The flow stress were investigat ed from the tension tests of sheets prestrained by rolling with temper ature range from 20 degrees C to 200 degrees C, and the flow stress eq uations were established from parameters of the volume fraction of mar tensite, material temperature, equivalent strain and strain rates. The rolling load, the volume fraction of martensite and the strip tempera ture calculated by this load prediction model were consistent with the experimental results. By using this load prediction model,it is made clear that the rolling load and the volume fraction of martensite depe nds on strip temperature and rolling speed greatly.