Abstract: The test free-cutting stainless steel TBPS (/% : 0.02C, 0.75Si, 1.50Mn, 0.008P, 0.21S, 19.70Cr, 1.10Mo, 0.llPb, 0.008Te) is melted by vacuum induction furnace + electro-slag remelting (ESR)(Φ350 mm, 500 kg ingot) , and the relative hot plasticity of MnS inclusion in ESR ingot with deformation 10%-70% at 900-1200 °C has been tested and studied by Thermomechanical Simulator Gleeble 3800. The results show that at 900-1100 ℃ with increasing deformation the relative plasticity index γ of MnS inclusion decreases ； at 1200 °C the effect of deformation on the relative plasticity index γ of MnS inclusion is minor ； and with increasing the deformation temperature, the relative plasticity index γ of MnS trends towards decreasing, especially at 1200℃; the relative plasticity index γ decreases obviously. In order to decrease the elongation deformation of MnS to get better free-cutting performance, it available for steel TBPS to hot deform by larger pass deformation at higher temperature.

Key words: Free-Cutting Stainless Steel TBPS, MnS Inclusion, Relative Hot Plasticity, Temperature, Deformation

摘要： 试验易切削不锈钢TBPS（/%:0.02C,0.75Si,1.50Mn,0.008 P,0.21S,19.70Cr,1.10Mo,0.11Pb,0.008Te）由真空感应炉+电渣重熔（Φ350 mm,500kg锭）冶炼,用Gleeble 3800热模拟机试验研究900~1200℃、变形量10%~70%时电渣锭中MnS夹杂的相对热塑性。结果表明,在900~1100℃时,随着变形量的增加,MnS夹杂的相对变形指数γ变小;在1200℃,变形量对MnS央杂相对变形指数γ影响较小;且随着变形温度升高,MnS夹杂的相对变形指数γ减小,特别在1200℃,相对变形指数γ显著减小;为降低MnS延展变形以获得较好的易切削性能,TBPS宜采用高的温度和大的道次变形量进行热变形。

关键词: 易切削不锈钢TBPS, 硫化锰夹杂, 相对热塑性, 温度, 变形量