18%Crステンレス鋼のリヂングに関する研究

抄録

It is one of the disadvantages in the use of 18% chrome stainless steel that a ridging phenomenon occurs when the cold rolled and annealed sheet or strip is drawn. The principal objects of the present study was to investigate a method to eliminate the ridging phenomenon and to clarify its origin, cesing commercially produced 18% chrome stainless steel. The results obtained were as follows: (1) The optimum treatment for 18% chrome stainless steel to develop the suitable mechanical properties is to heat-treat at 1100°C for 1∼3 min. (2) The facts that any ridging phenomenon did not occur either by quenching at 1100°C or by slow cooling from 1100°C, and the ridging phenomenon appeared in the rolling direction independent of the elongated direction, prove that the ridging phenomenon is not connected directly with the martensite itself. (3) As for the stainless steel with lower C and N contents(without α-γ zone), the ridging phenomenon is always shown by any heat treatment. (4) Cr is segregated at only grain boundaries, and this segregation is considered to have no direct relation with the ridging phenomenon. Mn is almost uniformly distributed. (5) The distribution of Cr and Mn is found to be independent of the C and N contents. Therefore, there would not be direct relation between the dispersion of chromium carbide and the ridging phenomenon. (6) The ridging phenomenon is closely related to the Fe-decreased banded structure produced by cold rolling.