硅铬系合金铸钢的组织与性能

Microstructure and Mechanical Properties of Chromium-Alloyed Silicon Cast Steel

研究了硅铬系合金铸钢在不同热处理工艺条件下的组织及力学性能。铸钢的铸态组织由片状马氏体和少量的残余奥氏体以及沿晶界呈连续网状分布的碳化物组成,经过空淬和回火处理之后得到回火马氏体和呈粒状分布的合金碳化物。硅铬系合金铸钢在1000℃奥氏体化,200℃回火时可获得最佳性能。研究表明,经过空淬和回火处理的硅铬系合金铸钢具有很高硬度和一定的冲击韧性,具有很好的耐冲击磨损性能,适合于对冲击韧性要求不是很高,但对耐磨性要求比较高的场合。

A new type of wear-resistant silicon chromium alloyed cast steel was developed. The microstructure and mechanical properties of five silicon chromium alloyed cast steels after various heat treatments have been studied. The as-cast microstructure of the various silicon chromium alloyed cast steels is composed of lamellar martensite and some retained austenite and continuous carbide network distributed on the grain boundary. The microstructure of tempered martensite and granular alloy carbide is obtained after air-cooled quenching and tempering treatment. It has been found that the optimized mechanical properties can be obtained after austenizing at about 1000°C and tempering at about 200°C. It is concluded that the silicon chromium alloyed cast steel has high hardness, proper impact toughness and high wear-resistance. This kind of steels is adequate to be used under conditions that need low impact toughness and high wear resistance.