| The non-metallic inclusions affect the quality of modulated wear-resistant steel directly.Therefore,it is of great significance to efficiently remove non-metallic inclusions in practical production.The paper aims to research the non metallic inclusions of inNanjing Iron and Steel Company in production.ASPEX was carried out to analyse the type,size,morphology and composition of inclusions through refining process.Secondly,comparing the inclusions of Nan Steel in wear resistant steel by Ca treatment to foreign.In addition,in order to further understand the influence of inclusions in steel for grain size in the steel structure,the real-time characteristics were observed using laser scanning confocal microscope.The following conclusions are obtained:（1）The size and number of non-metallic inclusions from wear-resistant steel by LF-RH--calcium tundish-finished steel processingdecreased significantly.The sizes of inclusions are mainly smaller than 10μm,TiN-Nb inclusions and CaS-CaO-Al2O3are main inclusions.（2）450 wear-resistant steel was mostly D class after being treated by calcium,and it was composed of CaO-Al2O3-CaS composite inclusions,and large particles TiN appeared in a few places.Compared with the control level of the inclusions of foreign steel,the inclusions in the thick plate of the 450 stage wear resistant steel of Nanjing Iron&steel Group Corp.are relatively large,and the hardness uniformity of the steel is relatively poor.（3）the melting point measured by a high temperature confocal microscope is similar to that of the theoretical melting point.The melting point of the steel should be 1480℃.The nucleation of bainitic ferrite will take place preferentially at twin boundaries,inclusions and dislocations.The preferential nucleation at inclusions is due to the effective reduction of interfacial energy and the reduction of phase transformation resistance.Thus it is beneficial to the nucleation. |
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