Formability of low-interstitial 18 pct Cr-2 pct Mo ferritic stainless steel

Because of its excellent corrosion resistance, low-interstitial 18 pct Cr-2 pct Mo ferritic stainless steel is being considered for a wide range of applications, many of which involve the forming of sheet. The present investigation was undertaken to examine the effects of rolling schedule on the formability of titanium-stabilized 18 pct Cr-2 pct Mo ferritic stainless steel sheet. Formability and texture development were evaluated by utilizing 1) plastic strain ratios and work-hardening exponents derived from tensile tests; 2) Swift and Olsen cup tests; and 3) X-ray pole figure analysis. Increasing the degree of cold reduction from 70 pct to 92 pct prior to the final recrystallization anneal led to substantial increases in deep drawability through changes in the recrystallization texture. Schedules of two-step cold rolling with an intervening recrystallization anneal, leading to increased total cold reduction, produced significantly higher plastic strain ratios than those produced by the one-step schedules. The crystallographic textures of the sheets were determined and correlated with the observedr values. This paper is based on a presentation made at a symposium on “New Developments in Ferritic and Duplex Stainless Steels,” held at the Fall Meeting in Cleveland, Ohio, on October 19, 1972, under the sponsorship of the Corrosion Resistant Metals Committee on TMS-IMD and the Corrosion and Oxidation Activity of the ASM.