The effects of sulfur addition methods and Ca-Si treatment on the microstructure and properties of free-cutting non-quenched and tempered steel 30MnVS were investigated by using optical microscopy, SEM and tensile tes...The effects of sulfur addition methods and Ca-Si treatment on the microstructure and properties of free-cutting non-quenched and tempered steel 30MnVS were investigated by using optical microscopy, SEM and tensile test methods. The results show that sulfur addition methods influence the morphology of sulfides and the properties of 30MnVS slightly. Ca-Si treatment is beneficial for the formation of complex sulfides which normally have oxide cores, therefore, improving the distribution of sulfides in the tested steel and enhancing its toughness. The two methods, pyrite addition during LF process and S wire feeding during VD process, slightly influence the morphology and distribution of sulfides and the properties of 30MnVS; Ca addition not only promotes the nucleation of sulfides on the cores of calcium aluminate inclusions, but also creates modification effect on MnS, reducing the relative plasticity and hot deformability of sulfides during hot rolling process, thereby reducing the length/width value of sulfides and improving their distribution, and significantly enhancing its mechanical properties, in particular, the impact toughness increased by 30%.展开更多
某公司采用130 t EAF-LF-RH-CC工艺路线冶炼钙硫系易切削齿轮钢817M40QT(出口德国),通过控制钢水纯净度、夹杂物形态组成、精准钙处理、精炼渣系控制、连铸防卷渣防氧化控制,实现由连铸替代模铸,并具备钙硫系易切削齿轮钢连浇8炉以上能...某公司采用130 t EAF-LF-RH-CC工艺路线冶炼钙硫系易切削齿轮钢817M40QT(出口德国),通过控制钢水纯净度、夹杂物形态组成、精准钙处理、精炼渣系控制、连铸防卷渣防氧化控制,实现由连铸替代模铸,并具备钙硫系易切削齿轮钢连浇8炉以上能力,且钢中的夹杂物水平能控制在:A类(细系/粗系):1.5/1.5;B类(细系/粗系):0.5/0.5;C类(细系/粗系):0/0;D类(细系/粗系):1.0/0.5,满足高纯净度要求。展开更多
西宁特钢Y15易切削钢(%:0.10～0.15C、1.00～1.20Mn、0.30S)由25 t EAF-LF-657 kg铸锭流程生产。试验结果表明,通过控制电弧炉氧化终点[C]0.06%～0.10%和脱氧工艺将[O]控制在(150～250)×10^(-6),控制钢中Mn/S=2.77、O/S=0.059时,...西宁特钢Y15易切削钢(%:0.10～0.15C、1.00～1.20Mn、0.30S)由25 t EAF-LF-657 kg铸锭流程生产。试验结果表明,通过控制电弧炉氧化终点[C]0.06%～0.10%和脱氧工艺将[O]控制在(150～250)×10^(-6),控制钢中Mn/S=2.77、O/S=0.059时,钢中夹杂物大多数为(Mn,Fe)S和硫化物包裹氧化物,少数为MnS,使钢具有良好的切削性能。展开更多
基金supported by the National Natural Science Foundation of China (No.50874007) and Beijing Municipal Education Committee, China
文摘The effects of sulfur addition methods and Ca-Si treatment on the microstructure and properties of free-cutting non-quenched and tempered steel 30MnVS were investigated by using optical microscopy, SEM and tensile test methods. The results show that sulfur addition methods influence the morphology of sulfides and the properties of 30MnVS slightly. Ca-Si treatment is beneficial for the formation of complex sulfides which normally have oxide cores, therefore, improving the distribution of sulfides in the tested steel and enhancing its toughness. The two methods, pyrite addition during LF process and S wire feeding during VD process, slightly influence the morphology and distribution of sulfides and the properties of 30MnVS; Ca addition not only promotes the nucleation of sulfides on the cores of calcium aluminate inclusions, but also creates modification effect on MnS, reducing the relative plasticity and hot deformability of sulfides during hot rolling process, thereby reducing the length/width value of sulfides and improving their distribution, and significantly enhancing its mechanical properties, in particular, the impact toughness increased by 30%.
文摘某公司采用130 t EAF-LF-RH-CC工艺路线冶炼钙硫系易切削齿轮钢817M40QT(出口德国),通过控制钢水纯净度、夹杂物形态组成、精准钙处理、精炼渣系控制、连铸防卷渣防氧化控制,实现由连铸替代模铸,并具备钙硫系易切削齿轮钢连浇8炉以上能力,且钢中的夹杂物水平能控制在:A类(细系/粗系):1.5/1.5;B类(细系/粗系):0.5/0.5;C类(细系/粗系):0/0;D类(细系/粗系):1.0/0.5,满足高纯净度要求。
文摘西宁特钢Y15易切削钢(%:0.10～0.15C、1.00～1.20Mn、0.30S)由25 t EAF-LF-657 kg铸锭流程生产。试验结果表明,通过控制电弧炉氧化终点[C]0.06%～0.10%和脱氧工艺将[O]控制在(150～250)×10^(-6),控制钢中Mn/S=2.77、O/S=0.059时,钢中夹杂物大多数为(Mn,Fe)S和硫化物包裹氧化物,少数为MnS,使钢具有良好的切削性能。
