高强度灰铸铁压缩机壳体的化学成分研究(2)

An Investigation on Chemical Compositions of High Strength Gray Iron Compressor Housing(Ⅱ)

根据空气压缩机壳体的使用性能要求,研究了N、Nb元素对灰铸铁金相组织和力学性能的影响和作用,优选出合理的化学成分,应用到空气压缩机壳体铸件上。以N、Nb为微合金化元素,采取复合孕育和增S工艺措施,获得体积分数超过95%的A型石墨,对金属基体的割裂作用小,铸件耐热疲劳、抗压和抗渗性能优越,高压腔室承压≥20 MPa、低压腔室承压≥6 MPa,经无损检测,未发现缩松、气孔或夹渣类缺陷,满足空气压缩机壳体金相组织、力学性能和使用性能要求。

According to the use properties requirements of the air compressor housing,the influence and effect of elements N,Nb on the metallurgical structure and mechanical properties of gray iron were studied,the reasonable chemical composition was preferably selected and applied to the air compressor housing. By using N,Nb as micro-alloying elements,adopting compound inoculation and S-increasing measure,the volume fraction more than 95% of A-type graphite was obtained,which had small separating effect on the metal matrix,the heat resistance fatigue,compression resistance and penetrating resistance of the casting was excellent,the pressure-bearing ability of the high pressure chamber was ≥20 MPa,the pressure-bearing ability of the low pressure chamber was≥6 MPa,the nondestructive examination didn’t found shrinkage porosity,blowhole or slag inclusion,totally met requirements of metallurgical structure,mechanical properties and usage performance.