当前位置：首页 > 过刊浏览->2022年43卷第11期
Sn 元素对 CN7M 铸件裂纹缺陷影响及 控制措施分析
Analysis on the Effect of Sn on Crack Defects of CN7M Castings and Control Measures
浏览(3350) 下载(10)
- DOI:
- 作者:
- 纪洪双 1 ，李 琦 2 ，曹 峤 1 ，唐维洋 1
JI Hongshuang1 , Li Qi2 , CAO Qiao1 , TANG Weiyang1
- 作者单位:
- 1. 江苏万恒铸业有限公司，江苏 盐城 224500；2. 黄淮学院 智能制造学院，河南 驻马店 463000
1. Jiangsu Wanheng Casting Co., Ltd., Yancheng 224500, China; 2. Intelligent Manufacturing College, Huanghuai University, Zhumadian 463000, China
- 关键词:
- 不锈钢；Sn；裂纹；偏析
stainless steel; Stannum; crack; segregation
- 摘要:
- 在阀门铸钢件的生产实践中，由于使用不合格的母合金棒料熔炼浇注 CN7M 材质精铸件，导致铸件产生
大量裂纹。 通过金相分析发现裂纹是沿奥氏体晶界扩展，且裂纹附近存在大量析出颗粒。 通过扫描电镜以及能谱分析，
发现该析出相富含 Sn，其中 Sn 含量达到 0.05%~0.06%。 钢种的残余元素 Sn 严重影响了铸件的质量，Sn 含量偏高会促
使其在晶界偏聚，从而析出富含 Sn 的低熔点金属间化合物，降低晶间结合力，导致铸件产生大量裂纹。 经生产验证，采
用合适的中间合金代替原 CN7M 棒料进行配料并熔炼浇注铸件，并严格控制 Sn 含量在 0.01%以下，可完全消除裂纹。
In the production practice of valve steel castings, an unqualified master alloy bar was used to melt and pour the investment casting of CN7M material, leading to a large number of cracks in the castings. The metallographic analysis shows that the cracks spread along the grain boundary of austenite, and many precipitated particles are found near the cracks. Scanning electron microscopy and energy spectrum analysis show that the precipitated phase is rich in Sn, with the content reaching 0.05% ~0.06%. The content of the residual element Sn in steel species seriously affects the quality of castings. A high Sn content promotes segregation at the grain boundary, resulting in the precipitation of Sn-rich low melting point intermetallic compounds, thus reducing the intercrystalline bonding force and finally leading to a large number of cracks in the castings. Production demonstrates that cracks can be completely eliminated by using an appropriate intermediate alloy instead of the original CN7M rod material for batching, melting and casting and strictly controlling the Sn content below 0.01%.