Microstructure and Mechanical Properties of a Duplex Martensite Austenitic Steel Precipitation-hardened by VC Carbide

摘要

This paper presents an investigation on the primary microstructure and mechanical properties of a martensite-austenitic duplex steel precipitation-hardened by VC carbide. The results show that the mechanical properties at room temperature are strongly dependent upon the volume fraction of austenite fA. When fA 32%, with increasing the.fA. ultimate strength rises and yield strength drops down. Experimental results at elevated temperatures. show that when test temperature ≤500℃. the yield strength to modulus ratio remains unchanged, however. as the temperature rises a substantial fall in the ratio occurs. The strength values at 600 and 700℃ are increased with increasing strain rate measured by cross-head speed of testing rnachine, The law of mixtures and the contribution of strain-induced transformation from unstable austen ite to martensite to the mechanical properties are discussed.