高碳当量含氮机床灰铸铁件的研制与应用(1)  

Development and Application of High Carbon Equivalent Nitrogen-containing Gray Iron Castings for Machine Tools(Ⅰ)

作　　者：徐清军 邢贝贝 张新霞 张学魁 靳存文 宋向阳 XU Qing-jun;XING Bei-bei;ZHANG Xin-xia;ZHANG Xue-kui;JIN Cun-wen;SONG Xiang-yang(Henan Golden Sun Precision Casting Co.,Ltd.,Xinxiang 453000,China)

机构地区：[1]河南省金太阳精密铸业股份有限公司,河南新乡453000

出　　处：《现代铸铁》2023年第5期12-16,20,21,共7页Modern Cast Iron

摘　　要：研究了氮含量和锡含量对灰铸铁的金相组织及性能的影响,优化出较为合理的氮含量为0.0080%~0.0100%,锡含量为0.03%~0.05%。开发了铸件厚大断面覆砂冷铁工艺,优化了冷铁尺寸及覆砂层厚度,提高了铁液中的溶氮能力,设计了型内保温工艺,降低了铸件残余应力,通过采用高碳当量+氮+锡熔炼技术在床身铸件上进行生产,铸件各项指标达到技术要求,即:碳当量3.80%~3.90%,A型石墨≥90%,石墨大小4~5级,珠光体体积分数≥98%,抗拉强度≥300 MPa,硬度190±10 HBW,弹性模量≥120 GPa,铸件铸态残余应力≤50 MPa。连续生产100炉次,各项性能全部合格。The effects of nitrogen content and tin content on the metallographic structure and properties of gray iron were studied.A more reasonable nitrogen content was optimized which was between 0.0080%and 0.0100%,and the tin content was between 0.03%and 0.05%.A sand-coated cold iron process for thick and large cross-sections of castings was developed.The size of the cold iron and the thickness of the sand coating layer were optimized.The nitrogen dissolving capacity in the molten iron was improved.An in-mold thermal insulation process was designed and it reduced the residual stress in castings.By using high carbon equivalent,nitrogen and tin smelting technology in the machine tool bed castings production,all indicators met the technical requirements.That were:carbon equivalent were between 3.80%~3.90%,type A graphite proportion was more than 90%,graphite size was between 4~5,pearlite volume was more than 98%,tensile strength was more than 300 MPa,hardness was 190±10 HBW,elastic modulus reached 120 GPa and as-cast residual stress was less than 50 MPa.All properties of the castings in continuously produced 100 batches were qualified.

关 键 词：灰铸铁 机床铸件 高碳当量 氮 锡 

分 类 号：TG251[金属学及工艺—铸造]