FERRITIC STAINLESS STEEL FOR AUTOMOBILE EXHAUST SYSTEM EXCELLENT IN FORMABILITY AND HEAT RESISTANCE

摘要

PURPOSE: To produce a ferritic stainless steel in which formability and heat resistance are secured by subjecting a stainless steel having a specified componental compsn. to hot rolling and thereafter regulating the form factor of the crystalline grains in the cross section of the sheet thickness parallel to the rolling direction. ;CONSTITUTION: The componental compsn. of a stainless steel is constituted of the one contg., by weight, ≤0.03% C+N, 0.05 to 2.0% Si, 0.1 to 2.0% Mn and 10 to 25% Cr, furthermore contg. at least one kind of 0.02 to 0.5% Ti and 0.05 to 1.0% Nb in the ranges so as to satisfy C/12+N/14≤Ti/48+Nb/93, and the balance Fe with inevitable impurities. This steel is subjected to hot rolling, and in a state being subjected to annealing after the hot rolling or as hot-rolled, the form factor of the crystalline grains in the cross section of the sheet thickness parallel to the rolling direction is regulated to ≤5. Thus, the material for an automobile exhaust system can be provided.;COPYRIGHT: (C)1995,JPO