Tensile Strength-Hardness Relationships in Thermomechanically Treated Steels

摘要

Data have been assembled from various sources on the strength and hardness of a number of steels after various thermomechanical treatments. These processes include the following types: I. martensite formed from coldworked austenite; II. martensite formed directly during the cold working of austenite; and III. martensite or other transformation products of austenite cold worked and aged. Steels represented include various carbon and alloy steels as well as stainless steels. The published ASTM tensile strength-hardness correlation adequately describes the data for the standard quenched and tempered condition. The data for Type I thermomechanical treatment also follow this relation, although with somewhat greater scatter. For cold-worked martensite, Type III, the tensile strength is generally higher than would be predicted from the ASTM curve, and the magnitude of this deviation increases with increasing amounts of cold working of the martensite. Type II treatments occupy an intermediate position. Utilizing the known effect of thermomechanical treatments on strain-hardening properties, it is possible to extend Tabor's analysis of the tensile strength-hardness correlation to explain the behavior of thermomechanically treated steels. (Author)