The remelting behavior of the tempering steel 50CrMo4, was investigated with several experimental melts on a lab-scale ESR-plant. The investigated parameters included a variation of the slag compositions and the use of a protective nitrogen atmosphere. Variations of the slag composition comprised slags with different contents of CaF2, CaO and AI2O3 as well as a variation of the SiC>2-content. The remelted ingots were forged and analyzed regarding their chemical composition as well as their distribution and composition of the non-metallic inclusions (NMI) by automated SEM-EDX method. The chemical composition of the slag after remelting was analyzed as well. The results clearly show a relationship mainly of Si and Al in the steel with the process parameters. NMI changed in their total amount, type and size distribution. The protective atmosphere reduced the Si-losses during remelting. The majority of the NMI were of the Al2O3-& MnS-type. In general, remelting lead to an almost complete removal of sulfides, a reduction of oxisulfides and a shift towards more oxides. The total amount of NMI was most strongly reduced by the high CaF2-containing remelting slag.
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机译：回火钢50CrMo4重熔行为，与在实验室规模的ESR厂几个实验熔体调查。所研究的参数包括在炉渣组合物的变型和使用保护氮气氛。与氟化钙，CaO和Al 2 O 3的不同内容，以及在SiC> 2含量的变化的矿渣组合物包含炉渣的变化。重熔铸锭锻造和分析关于其化学组成，以及其通过自动SEM-EDX法的非金属夹杂物（NMI）的分布和组成。重熔后的矿渣的化学成分进行了分析，以及。结果清楚地表明在钢与过程参数的关系为主的Si和Al。 NMI在它们的总数量，类型和尺寸分布改变。保护气氛重熔过程中减少硅损失。大多数NMI的人的Al2O3-及的MnS型。一般情况下，重熔导致几乎完全除去硫化物，降低oxisulfides的并且朝向多种氧化物的转变。 NMI的总量最强烈重熔炉渣高含有氟化钙还原。
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