碲处理改善汽车曲轴用非调质钢38MnVS6硫化物形貌的研究

Improving Sulfide Morphology of Non-quenched and Tempered Steel 38MnVS6 for Automobile Crankshaft by Tellurium Treatment

为研究碲元素对汽车曲轴用非调质钢38MnVS6硫化物形貌的影响,在冶炼过程中喂入70 m的Mn-Te线,加入0.012%Te,通过金相显微镜及扫描电镜对Φ380 mm连铸圆坯及Φ105 mm热轧圆钢的非金属夹杂物进行研究。研究发现,硫化物的形态在连铸坯横向与纵向的形态相同;MnS与MnTe形成共晶化合物,MnTe的存在改变了MnS的析出形态,可以使硫化物形态向短杆甚至椭球态转变,整体长度尺寸变小,平均长度由45μm缩短为15μm;加入0.012%Te后,MnTe与MnS两种夹杂物发生固溶,轧材夹杂物与铸坯相似,而未Te处理的圆钢硫化物随轧制的方向被明显的拉长。

In order to study the effect of tellurium on sulfide morphology of non-quenched and tempered steel 38MnVS6 for automobile crankshaft,0.012%Te is added by feeding 70 m Mn-Te wire in the smelting process to achieve the purpose of tellurium treatment.The nonmetallic inclusions inΦ380 mm continuous casting round bloom andΦ105 mm hot rolling round bar are studied by metallographic microscope and scanning electron microscope.Through the research,it is found that the morphology of sulfide is the same in the transverse and longitudinal direction of continuous casting bloom.MnS and MnTe form eutectic compounds,and the existence of MnTe changes the precipitation morphology of MnS,which can make the sulfide morphology change to short rod or even ellipsoid,and the overall length and size become smaller performace to reduce average length from 45μm to 15μm.Affer adding 0.012%Te,MnTe and MnS inclusions occur solid solution,and the morphology of inclusions is very similar in both size and morphology in bloom and rolled bar,while the sulfide in rolled bar without Te treatment is obviously elongated with the rolling direction.