以球铁代铸钢气室支架的生产工艺

介绍了某气室支架的铸件结构及技术要求,根据技术要求在铸件结构上进行了改进,在应力较大的部分增加圆角过度,并将筋板掏空,使铸件质量减轻;在材料上,选用QT600-10代替ZG310-510,利用3 t中频炉单熔炼,原铁液成分为:w(C)3.7%~3.8%,w(Si)1.6%~1.9%,w(P)≤0.04%,w(S)≤0.02%,w(Mn)0.3%~0.4%,w(Cu)0.3%~0.4%,采用低Mg低RE的球化剂,加入量1%~1.1%,冲入法球化处理,一次孕育采用含Ba的SiFe孕育剂,加入量0.5%~0.6%,二次随流孕育采用Ba-Sr孕育剂,加入量为0.1%,出炉温度1 500~1 520℃,浇注温度1 400~1 440℃。最终生产的铸件金相组织和力学性能均符合技术要求,铸件气孔、砂眼、裂纹等铸造缺陷不超过0.5%,达到技术要求。

Production Process of Chamber Bracket Made of Ductile Iron instead of Cast Steel

The structure and technical requirements of casting chamber bracket was introduced. Some improvements on casting structure were made according to the technical requirements. They were：adding fillet on large stress position and hollowing the ribs to reduce the weight of casting. QT600-10 was used instead of ZG310-510. It was melted by 3 t medium frequency furnace and its composition was w（C） 3.7%~3.8%,w（Si） 1.6%~1.9%,w（P）≤0.04%,w（S）≤0.02%,w（Mn） 0.3%-0.4%,w（Cu） 0.3%-0.4%. Pour-over nodulizer with low Mg and RE was added by 1%~1.1%. For primary inoculation,the inoculants is SiFe with Ba and added by 0.5%,~0.6%. For second inoculation with flow process,the inoculants was Ba-Sr and added by 0.1%. The tapping temperature was between 1 500℃ and 1 520℃ ,pouring temperature was between 1 400 ℃ and 1 440℃. As a result,the microstructure and mechanical properties of the final casting meet the technical requirements,which was the casting defects includes porosity,blisters and cracks were below 0.5%.