Effect of Si on mechanical properties of low alloy steels

Abstract

The effect of Si content on mechanical properties in 0·6C–(1·0–2·5)Si–2Ni–0·2V (wt-%) steels was investigated using tensile tests, Charpy impact tests, and microstructural examination with transmission electron microscopy. The results showed that the tempering temperatures both for the maximum yield strength and for the softening of low alloy steel shifted to higher temperatures owing to the retardation of the conversion of ɛ carbide to cementite within martensite laths caused by Si addition. Additionally, it was found that increasing Si content shifted the tempered martensite embrittlement temperatures upwards, owing to the retardation of the formation and growth of cementite boundaries caused by the added Si.