阀门铸钢件的裂纹缺陷分析及工艺控制.PDFVIP

2 2 2 2 2 铸造技术 Vol. 29 No. 7 · 860 · FOUNDR Y TECHNOLO GY J ul 2008 阀门铸钢件的裂纹缺陷分析及工艺控制 陈淑惠 (陕西工业职业技术学院 ,陕西 咸阳 712000) 摘要 :分析了阀门铸钢件经常出现的裂纹缺陷的形成原因 ,从生产角度提出了防止和消除裂纹的工艺措施 。主要强调以下几 点 :提高型芯的退让性 ,以减小收缩应力 ,将芯子做成中空结构效果明显 ;严格控制化学成分 ,特别是硫 、磷等易形成低熔点共 晶物的元素 ;细化晶粒 ,净化钢液 ,以提高抗裂性 ,加入稀土元素可以兼得 ;采用冷铁 ,适当提高浇注速度 ,在保证良好补缩的 2 2 2 2 前提下减弱顺序凝固 ,使铸件局部实现同时凝固 ,减小热应力 。 2 关键词 :阀门铸钢件 ;裂纹缺陷 ;工艺控制 中图分类号 : TG269 　　文献标识码 :A 　　文章编号 :1000 8365 (2008) 07 0860 04 Anal ys is o n Cra c k Def e c t s a n d Pr oc e s s Co nt r ol of Val ve S t e el Ca s ti n g CHEN Shu hui ( Shaanxi Polytechnic Institute , Xianyang 712000 , China) Abs t rac t : The reason that causes cracks of valve castings was analyzed , the measures to prevent and eliminate cracks was propo sed. The following points were emphasized : the hollow structure of core can improve yieldability and reduce the shrinkage stress ; the chemical compo sition should be controlled strictly , particular sulfur , pho sphorus which can easily form low melting eutectic ; Adding RE can refine grains , purify liquid steel and enhance crack resistance ; Using iron chill , increasing pouring temperature and weakening progressive solidification under the premise of ensuring good feeding , can realize casting regional simultaneous solidification , thus reduce the thermal stress. Ke y w ords :Valve steel castings ; Crack defects ; Process control 　　阀门在国民经济中应用非常