新型易切削不锈钢TBPS中MnS夹杂相对热塑性的试验研究

Test and Study on Relative Hot Plasticity of MnS Inclusion in a New Free-Cutting Stainless Steel TBPS

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（ΦP350 mm,500 kg锭）冶炼,用Gleeble3800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。

The test free-cutting stainless steel TBPS （/%： 0. 02C, 0.75Si, 1.50Mn, 0. O08P, 0.21S, 19. 70Cr, 1.10Mo, 0.11Pb, 0. 008Te） is mehed by vacuum induction furnace ＋ electro-slag remehing （ESR） （Φ350 mm, 500 kg ingot） , and the relative hot plasticity of MnS inclusion in ESR ingot with deformation 10% -70% at 900 ~ 1 200 ℃ has been tested and studied by Thermomeehanical Simulator Gleeble 3800. The results show that at 900 - 1 100 ℃ with in- creasing deformation the relative plasticity index γof MnS inclusion decreases; at 1 200 ℃ the effect of deformation on the relative plasticity index γ of MnS inclusion is minor; and with increasing the deformation temperature, the relative plastieity index γof MnS trends towards decreasing, especially at 1 200 ℃ the relative plasticity index γ decreases obviously. In or- der to decrease the elongation deformation of MnS to get better free-cvtting perfommnce, it available for steel TBPS to hot deform by larger pass deformation at higher temperature.