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通过对保护气氛电渣重熔工艺和普通电渣重熔工艺H13钢的锻材成分、氧化物夹杂的组成分析,研究了电渣重熔工艺H13钢中Mg-Al-O系夹杂物的形成机理及控制问题,并通过Factsage软件对Mg-Al-O系夹杂物的各优势区进行了理论计算。结果表明,保护气氛电渣重熔工艺中氧质量分数较低,仅为0.001 5%,氧化物夹杂主要是MgO·Al_2O_3,1~3μm的小尺寸占比达到了62.5%;普通电渣重熔工艺中氧质量分数较高,达到了0.002 4%,Mg-Al-O系夹杂物以72.5%Al_2O_3+27.5%MgO·Al_2O_3为主,含有4%的5~8μm大尺寸夹杂物,1~3μm小尺寸占比仅为37.8%,尺寸偏大。钢液中镁、氧质量分数的变化对MgO·Al_2O_3的优势区域影响较大,高镁、低氧有利于MgO·Al_2O_3生成,减小H13钢中氧化物夹杂尺寸。但MgO·Al_2O_3会作为大尺寸碳氮化物(Ti,Nb,V)(C,N)异质形核核心,后期对此问题还要做进一步研究。
The formation of Mg-Al-O inclusions in ESR H13 steel was studied through the composition analysis of the inclusions and oxide inclusions in ESR process and ESR H13 steel Mechanism and control of the Mg-Al-O inclusions were calculated theoretically by Factsage software. The results showed that the oxygen content in the protective atmosphere was lower than 0.001 5% in the ESR process, the inclusions were mainly MgO · Al 2 O 3 and the small size accounted for 62.5% The content of oxygen in the process is relatively high, reaching 0.002 4%. The Mg-Al-O inclusions are dominated by 72.5% Al 2 O 3 + 27.5% MgO · Al 2 O 3 and contain 4% 5 ~ 8μm large inclusions and 1 ~ 3μm Small size accounted for only 37.8%, larger size. The changes of magnesium and oxygen mass fraction in molten steel have a great influence on the dominant region of MgO · Al 2 O 3. High magnesium and low oxygen are beneficial to the formation of MgO · Al 2 O 3 and reduce the inclusion size of oxide in H13 steel. However, MgO · Al 2 O 3 will act as heterogeneous nucleation center for large-size carbonitrides (Ti, Nb, V) (C, N), and further study on this issue later.