Influence of Heat Treatment on Mechanical Properties and Microstructure of Low Alloy Cast Steel (ZG25MnNi)

In this paper, the influence of heat treatment temperature on the microstructure and mechanical properties of cast steel (ZG25MnNi) was investigated. The results showed that normalizing treatment can effectively refine cast microstructure of ZG25MnNi and maximum hardness achieved at 900°C. After normalized at 900°C, the sample tempered at 500°C,530°C,560°C, 590°C, 620°C, 650°C respectively. With the tempering temperature increasing, the samples tensile strength increased gradually and elongation decreased gradually. When tempered at 530-590°C, the sample had a relatively high strength plastic product. The results showed that the best normalizing temperature is 900°C and the optimum tempering temperature is 530-590°C.