树脂砂铸造球铁件表层球化不良的改进  

Reason and Prevention of Under-Nodularizing on Resin Sand Casting Ductile Iron Surface

作　　者：张福强 石利军 

机构地区：[1]一汽铸造有限公司特种铸造厂,吉林长春130011

出　　处：《现代铸铁》2017年第1期67-69,共3页Modern Cast Iron

摘　　要：对呋喃树脂砂铸造球墨铸铁砂箱加工面灰斑缺陷进行了金相组织分析,确认灰斑缺陷是由球化衰退导致,为此分析了灰斑部位和正常部位的化学成分,发现灰斑区域的S和C都明显高于正常区域,因此断定球化衰退是由于树脂砂中的S渗入到铸铁件表面,使球状石墨畸变而引起的。为解决灰斑问题,采取了如下防止措施:(1)在铸件渗S部位设置冷铁;(2)在砂型表面用涂料阻隔含S气氛渗入到铸件表层;(3)控制树脂及固化剂加入量,减小灼烧减量,使树脂砂w(S)量降低。生产结果显示,铸件加工表面灰斑问题获得解决。Metallographic structure analysis of the gray patch defect on furan resin sand casting machining surface was processed. Gray spot defect was a result of the under-nodularizing. The chemical constituents of the gray spot and the normal part were analyzed. The S and C were higher than normal in gray spot. So it could be deduced that under-nodularizing was the result of distortion of spherical graphite by S penetrating into the cast iron surface from resin. In order to solve the problem, the following measures were taken：（ 1 ）Chilling was set on the penetrating part. （2）A coating was used to prevent S penetrating. （3）Control the amount of resin and curing agent and reduce loss on ignition to reduce w（S） in furan resin. The result shown that the gray spot on the sand box machining surface was solved.

关 键 词：球墨铸铁 呋喃树脂 球化衰退 渗S 

分 类 号：TG255[金属学及工艺—铸造]