HB450低合金超高强耐磨钢组织与性能

在实验室条件下,设计了一种新型Ti-Cr-B系列HB450高韧性低合金超高强耐磨钢.研究了该类钢的基本特征、显微组织、析出物形态以及冷却速度对其组织和性能的影响.研究结果表明,试验钢具有良好的淬透性,在冷速大于20℃/s时即可获得大量的马氏体组织;试验钢在控制轧制后以950℃淬火,250～300℃回火时可获得细小均匀的回火马氏体+残余奥氏体组织,其布氏硬度达到450左右,具有良好的强韧性配合,满足HB450低合金耐磨钢性能要求;透射电镜分析表明,在250℃回火时,大量ε-FexC在马氏体板条内析出,该类碳化物对试验钢的强化起着极其重要的作用.

Microstructure and Mechanical Properties of HB450 Ultra-High Strength Low-Alloy Abrasion Resistant Steel

The new type of Ti-Cr-B HB450 low-alloy abrasion resistant steel was designed on lab conditions. The basic characteristics, microstructure, precipitates and effects of cooling rate on microstructure and mechanical properties of the steel were also investigated. The results showed that the steel has high hardenability, and lots of martensite structure can be found when the cooling rate is higher than 20°C/s. After controlled rolling, quenching at 950°Cand tempering in the range from 250 to 300°C, the fine martensite plus residual austenite can be got with hardness up to HB450 in combination with high toughness, thus meeting the requirements of HB450 ultra-high strength low-alloy abrasion resistant steel. The TEM analyses showed that Ε-carbide particles precipitate in the lath martensite when tempering at 250°C, and these carbide precipitates play a very important role in strengthening the steel.