一种中强度耐低温铸钢材料组织与性能研究

为满足高寒地区中强度低合金铸钢的低温使用要求,在B+级钢的基础上,依据合金元素对韧脆转变温度影响进行成分优化设计。试验分析3种不同热处理工艺对材料低温冲击性能的影响,理论与试验结合研究了不同Nb含量对材料力学性能及组织的影响。结果表明:该低合金耐低温铸钢材料经正火预处理+调质处理后,可以满足?60 ℃温度下冲击吸收能量达到20 J的目标要求;当Nb含量为0.04%时,组织均匀,晶粒细化,低温冲击性能最好。

Microstructure and Properties of a Medium Strength Low Temperature Resistant Cast Steel

In order to meet the low temperature requirements of medium strength low alloy cast steel in high and cold region, the composition optimization of B+ grade steel was carried out according to the influence of alloy elements on ductile brittle transition temperature. The effects of three different heat treatment processes on the low temperature impact properties of the material were investigated. The effects of niobium content on the mechanical properties and microstructure of the material were studied by combining theory with experiment. After normalizing pretreatment, quenching and tempering treatment, the impact energy absorption of the low alloy low temperature resistant cast steel can reach 20 J at ?60 ℃, whitch meets the performance requirement. When the Nb content is 0.04%, the microstructure is uniform, the grain is refined, and the low temperature impact property is the best.