Abstract: According to metallurgical quality issue about low billet yield of hot working die steel H13 at steel works, the statistic analysis on relative quality to influence on billet yield has been carried out to get that the porosity defects caused by poor insulation of hot top make up 58%-76% of the total non-qualified ingot. With decreasing the volume density and heat conductivity of SiO₂ insulating board respectively from original 1.65 g/cm³ and 0.317 W/(m • K) to 0.87 g/cm³ and 0.21 W/( m • K) , and optimizing the ingredient of low carbon shield synthetic flux to decrease its melting point and viscosity respectively from original 1258 °C and 1.8 Pa • s to 1147 °C and 0.9 Pa • s, the average billet yield of ingot increases from original 75% to 80% .

Key words: Hot Working Die Steel H13, Ingot Hot Top, Insolating Board, Shielding Flux, Billet Yield

摘要： 针对钢厂热作模具钢H13成坯率低的冶金质量问题,对影响成坯率的相关质量进行了统计分析,得出因帽口保温性能差所造成的疏松缺陷占不合格钢锭总量的58%~76%。通过将SiO₂绝热板的体积密度和导热率分别由1.65 g/cm³和0.317 W/(m·K)降至0.87 g/cm³和0.21 W/(m·K),优化低碳复合保护渣的组成,使其熔点和粘度分别由原来的1258℃和1.8 Pa·s降至1147℃和0.9 Pa·s,使钢锭平均成坯率由原来的75%提高至80%。

关键词: H13热作模具钢, 铸锭帽口, 绝热板, 保护渣, 成坯率