Abstract: The production flow sheet of steel S34MnV for marine crank is 100 t Consteel arc furnace-LF-VD + VC (vacuum casting) -ingot process. The observation and analysis on samples of defect region of steel S34MnV ingot are carried out by using scanning electron microscope and numerical simulation to get that the a large amount of non-metallic inclusions enriched at deposit cone of ingot is the cause of rejection of crank by non-destructive test. With using optimum process measures including feeding 2 m/t aluminium wire to deep-deoxidize before refining, feeding Ca-Si wire for end deoxidization, controlling type of inclusions in steel, adjusting slag series and optimizing structure of steel ingot mold etc. the defects at deposit cone of ingot reduce, the rejection rate of ingot is reduced to 6% from original 21% and the oxygen content in steel of ingot bottom decreases to 12 x 10^-6 from original 23 x 10^-6.

摘要： 曲柄用钢S34-MnV的生产流程为100 t Consteel电弧炉-LF-VD+VC(真空浇注)-铸锭工艺。运用扫描电镜和数值模拟对S34MnV钢锭缺陷部位钢样进行了观察和分析,得出造成曲柄探伤不合的原因为钢锭沉积锥处有大量非金属夹杂物富集。通过精炼前喂2 m/t铝线深脱氧、终脱氧喂Ca-si线,控制钢中夹杂物类型,调整渣系、优化钢锭模结构等优化工艺措施,减轻了钢锭的沉积锥缺陷,使钢锭废品率由原来的21%降低至6%,钢锭尾部氧含量由原来的23×10^-6降低至12×10^-6。

关键词: 船用曲柄钢S34MnV, 钢锭, 沉积锥, 夹杂物, 工艺优化