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

Author of the article:LIU Jinwang

Author's Workplace：CNNC Sida Construction Supervision Co., Ltd., Shijiazhuang 050000, China

Key Words：duplex stainless steel; valve castings; crack

Abstract：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.