Effect of Zerolling on Properties of Modified Type 347 Stainless Steel

Abstract

Chromium-nickel stainless steels have excellent properties at subzero temperatures. All metallic materials increase in strength as temperature is reduced below 0 F, but unfortunately the increase in strength is often accomplished by decreased ductility and increased brittleness. However, the annealed 18-8 alloys, as shown by Colbeck, McGillivray, and Manning (1), Rosenberg (2), McAdam, Geil, and Cromwell (3), and many other investigators, show a great increase in tensile strength at subzero temperatures without any great loss in ductility, reduction of area, or impact resistance. Krivobok and Talbot (4) and Zambrow and Fontana (5) showed that 18-8 alloys rolled to high tensile strength at room temperature exhibited much better ductility at temperatures down to −320 F than at room temperature, and at the same time the tensile strengths were increased. Zambrow and Fontana also investigated the effect of temperature on the impact strength. They found that at temperatures down to −423 F, the lowest temperature investigated, cold-rolled type 304 stainless steel had better impact strength than at room temperature. Krivobok and Talbot (4) and Ziegler and Brace (6) showed that working stainless steels at subzero temperatures resulted in greatly increased tensile strengths. If these “zerolled” stainless steels are heated to temperatures up to 800 F, additional strengthening takes place. The increase was particularly noticeable in type 347 stainless steel. Thus it was decided to investigate these effects further.