Numerical analysis of effect of the solutes on formation of MnS in non-tempered steel

Abstract

ABSTRACTTo analyse the effects of solute elements on formation of MnS in the micro-alloyed non-tempered steel, a novel coupling model of micro-segregation and MnS precipitation during solidification was built using the finite-difference method. Non-tempered 49MnVS3 steel was used to detect the effects of concentrations of elements on the precipitation behaviour of MnS. The results show that with contents of Mn at 0.05∼2%, S at 0.001∼0.3%, Si at 0.3∼0.7%, P at 0.001∼0.05%, C at 0.05∼1.0%, the precipitation temperature of MnS raised from 1360 to 1432°C, 1397 to 1447°C, 1425 to 1418°C, 1425 to 1418°C, dropped from 1488 to 1358°C, and its precipitation solidification ratio dropped from 1 to 0.785, 1 to 0.51, 0.883 to 0.866, 0.88 to 0.86, 0.96 to 0.77, respectively; the observed temperature of MnS by HT-SM was 1427.2°C, close to the calculated temperature of 1420.6°C by the proposed the diffusion control growth model.