论文部分内容阅读
为提高金属材料的耐磨性,在普通低碳钢中加入B(2.5~4.0)%和Ti、N(0.20~0.40)%,获得了大量具有高硬度硼化物的铸造合金,并对其显微组织进行了观察和XRD分析。结果表明:铸造合金的铸态组织比较细密,由铁素体+珠光体+Fe2B组成,Fe2B呈连续网状沿晶界分布,铁素体呈不规则块状分布在硼化物周围,珠光体呈片层状分布在硼化物和铁素体之间;经980℃×2h+250℃×4h淬回火热处理后,铁素体和珠光体全部转变为强韧性均好的板条马氏体组织,Fe2B局部出现断网现象,仍呈网状分布;少量Ti、N元素的加入可细化奥氏体晶粒,显著改善Fe2B韧性。经测试,热处理铸造合金硬度≥60.2 HRC,冲击韧性≥25.5 J/cm2,耐磨性相对40Gr钢提高了2.5倍。
In order to improve the wear resistance of metal materials, B (2.5 ~ 4.0)% and Ti, N (0.20 ~ 0.40)% were added into common low carbon steel to obtain a large amount of cast alloy with high hardness boride, Microorganisms were observed and analyzed by XRD. The results show that the as-cast microstructure of the cast alloy is relatively fine and consists of ferrite + pearlite + Fe2B. Fe2B is continuously reticular distributed along the grain boundary. The ferrite is irregularly distributed around the boride. The pearlite Lamellar distribution between the boride and ferrite; After 980 ℃ × 2h +250 ℃ × 4h quenching and tempering heat treatment, the ferrite and pearlite all transformed into good martensitic toughness lath martensite , Fe2B partial network phenomenon, still reticular distribution; a small amount of Ti, N elements can be refined austenite grains, significantly improve the toughness of Fe2B. After testing, heat treatment cast alloy hardness ≥ 60.2 HRC, impact toughness ≥ 25.5 J / cm2, wear resistance relative to 40Gr steel increased by 2.5 times.