Abstract: Effect of 0 ~0. 072% La on inclusion, structure and elevated temperature tensile properties of 0. 20C stee] melted by a 10 kg medium frequency vacuum induction furnace has been studied by scanning electron microscope, energy dispersive X-ray spectrometer and Gleeble-1500 simulating test machine. Results showed that with rare earth metal La modified treated on inclusions in steel such as MnS and Al₂O₃, the ellipsoidal and spherical RE inclusions RE₂O₃, RE₂O₂S and RES with size ≤2 μm formed in steel, the hot ductility of 0. 20C steel at 850 〜1 050 °C obviously increased and the lath martensite structure in steel water-quenched after high temperature tensile test was finer than that non-adding La.

Key words: Rare Earth Element La, 0. 20C Steel, Inclusion, Hot Ductility

摘要： 通过10kg真空中频感应炉熔炼、扫描电镜、能谱分析和Gleeble-1500试验机热模拟试验研究了0～0.072%La对20钢夹杂物、组织和高温拉伸性能的影响。结果表明,经稀土金属镧对钢中MnS、Al₂O₃等夹杂物变质处理后,形成尺寸≤2μm的椭圆体和球形RE₂O₃、RE₂O₂S和RES稀土夹杂物,显著提高20钢在850～1050℃的热塑性,与未加La钢相比,高温拉伸后水冷的马氏体板条组织更细。

关键词: 稀土元素镧, 20钢, 夹杂物, 热塑性,