DEVELOPMENT OF HIGH STRENGTH AND FRACTURE TOUGHNESS IN STEELS THROUGH STRAIN-INDUCED TRANSFORMATIONS.

摘要

An investigation was made to determine the effects of variations in alloy content,cold-working temperature,and amount of cold work,on the tensile and toughness properties of metastable austenitic stainless steels. The purpose of this program was to arrive at an alloy composition and processing procedure that results in an optimum combination of strength and toughness in a structural sheet material that can be used in the fabrication of highly stressed structures,such as rocket motor casings. It was found that the optimum combination of high yield strength and fracture toughness is obtained by cold working alloys containing about 0.04% to 0.05% carbon. The effect of post-deformation heat treatments on the properties of the cold-worked stainless steels was found to be a function of the amount of deformation. In standard Type 301stainless steel cold reduced 40% to 50%,precipitation of fine carbides in transformed (martensitic) areas was evident after exposure to 800 F for 24hr. (Author)