论文部分内容阅读
采用金相显微镜、扫描电镜和透射电镜等分析方法,研究了Rm≥1 000 MPa、ReL≥750 MPa的高强度非调质钢的组织和性能。结果表明:材料为铁素体-珠光体组织,铁素体呈网状分布;珠光体片层间距对强度的影响较大,当片层间距从207 nm减少到171 nm时,屈服强度从820 MPa上升到840MPa;其析出第二相以(V,Ti)(C,N)为主,其晶粒尺寸为30~170 nm。随着析出相颗粒直径减小,其强度变化遵循Orowan强化机制逐渐增大,钢中的硫化物夹杂一方面可以细化铁素体-珠光体晶粒;另一方面可以包裹氧化物夹杂,减少氧化物的危害,这有利于改善试验钢的切削加工性能。
The microstructure and properties of high strength non-quenched and tempered steel with Rm≥1 000 MPa and ReL≥750 MPa were studied by metallographic microscope, scanning electron microscopy and transmission electron microscopy. The results show that the material is ferrite-pearlite and the ferrite is reticular. The pearlite layer spacing has a great influence on the strength. When the distance between layers decreases from 207 nm to 171 nm, the yield strength changes from 820 MPa increased to 840MPa. The precipitated second phase mainly consisted of (V, Ti) (C, N) with the grain size of 30-170 nm. As the precipitated phase decreases in particle size, the strength changes follow the Orowan strengthening mechanism. The sulfide inclusions in steel can refine the ferrite-pearlite grains on the one hand and the oxide inclusions on the other hand decrease Oxide hazards, which is conducive to improving the machinability of the test steel.