球墨铸铁热浸渗铝工艺研究  

Study on Hot Dip Aluminizing Process of Nodular Cast Iron

作　　者：吴笛 张杰[3] 陈汉卿 高宗华 WU Di;ZHANG Jie;CHEN Han-qing;GAO Zong-hua(Lanzhou Petrochemical University of Vocational Technology,School of Mechanical Engineering,Lanzhou 730060,China;Quality Administration Department,School of Mechanical Engineering,Lanzhou 730060,China;Lanzhou Petrochemical Company,CNPC,Lanzhou 730060,China)

机构地区：[1]兰州石化职业技术大学质量管理处,甘肃兰州730060 [2]兰州石化职业技术大学机械工程学院,甘肃兰州730060 [3]中国石油兰州石化分公司炼油厂,甘肃兰州730060

出　　处：《石油化工设备》2022年第5期17-21,共5页Petro-Chemical Equipment

基　　金：甘肃省高等学校创新基金项目(2021A-213)。

摘　　要：在实验室条件下,研究了球墨铸铁热浸渗铝工艺和工艺参数对渗层的影响,对球墨铸铁渗层形成机理进行了分析。研究结果表明,在助镀剂等试验条件确定的情况下,球墨铸铁的最佳热浸镀铝工艺参数组合为,浸镀温度740℃、浸镀时间6 min、扩散温度850℃、扩散时间5 h。扩散温度应控制在850℃以下,过高的扩散温度不会获得扩散层厚度的明显增加,而且还增大了基体中的石墨氧化的可能性,从而对基体性能造成不良影响。扩散时间应控制在5 h以内,过长的扩散时间易导致球墨铸铁表面的Al_(2)O_(3)膜开裂。热浸镀铝层由表面富铝层和扩散层构成,富铝层主要为Al相和针状FeAl_(3)相,扩散层主要成分为FeAl和Fe_(2)Al_(5)相。随着扩散时间的延长,Fe_(2)Al_(5)层厚度先增大后减小,FeAl层厚度增大,但增速逐渐放缓。The influence of the hot dip aluminizing process and process parameters on the permeable layer of nodular cast iron was studied under laboratory conditions,and the formation mechanism of the permeable layer of nodular cast iron was analyzed.The results show that the optimal hot dip aluminum plating process parameters of nodular cast iron are as follows:dip temperature 740℃,dip time 6 min,diffusion temperature 850℃,diffusion time 5 h.The excessive diffusion temperature will not result in a significant increase in the thickness of the diffusion layer,but increases the possibility of oxidation of graphite,thereby adversely affecting matrix properties.When the diffusion temperature reaches 850℃,the thickness change is not obvious,and the graphite in the matrix is easily oxidized,which affects the properties of the matrix.When the diffusion time exceeds 5 h,the Al_(2)O_(3) film on the surface is easy to crack.The hot dip aluminum plating layer is composed of a surface Al-rich layer and a diffusion layer.The Al-rich layer is mainly composed of Al phase and needle-like FeAl_(3) phase,and the diffusion layer is mainly composed of FeAl and Fe_(2)Al_(5) phase.With the extension of diffusion time,the thickness of Fe_(2)Al_(5) layer increases first and then decreases,while the thickness of FeAl layer increases,but the growth rate gradually slows down.

关 键 词：球墨铸铁 热浸渗铝 扩散处理 扩散层 

分 类 号：TQ050.4[化学工程]