双相不锈钢阀门铸件的裂纹缺陷分析及避免措施

Crack Defect Analysis and Preventing Measures of Duplex Stainless Steel Valve Castings

分析了双相不锈钢阀门铸件经常出现裂纹缺陷的原因。为避免再次投产时阀门铸件裂纹缺陷的产生,制定了相应的措施:提高砂芯的退让性;严格控制钢液的化学成分,特别是磷硫元素的含量控制;添加稀土元素细化晶粒,净化钢液以提高抗裂性;清除浇冒口和补焊注意温度的控制。结果表明,通过上述措施后,重新投产的阀门铸件没有裂纹缺陷。

The causes of frequent crack defects in duplex stainless steel valve castings were analyzed.In order to avoid the occurrence of crack defects in valve casting when the valve was put into production again,the corresponding measures were formulated:improving the deformability of sand core;Strictly control the chemical composition of molten steel,especially the content of phosphorus and sulfur;Rare earth elements were added to refine grain and purify liquid steel to improve crack resistance.Clear riser and repair welding temperature control.The results show that there is no crack defect in the valve casting after the above measures.