钼合金穿孔顶头失效分析  

Failure Analysis of Mo Alloy Piercing Plug

作　　者：周红灯 徐文进 田青超 ZHOU Hongdeng;XU Wenjin;TIAN Qingchao(State Key Laboratory of Advanced Special Steel,Shanghai University,Shanghai 200444,China)

机构地区：[1]上海大学省部共建高品质特殊钢冶金与制备国家重点实验室,上海200444

出　　处：《钢管》2023年第1期78-83,共6页Steel Pipe

摘　　要：分析了钼合金顶头穿制高镍铬不锈钢管时表面发生龟裂的原因,同时以正常顶头为参照进行对比分析。结果表明,钼合金顶头的开裂为热应力疲劳开裂,裂纹源区位于钼合金顶头穿孔锥表面的复杂应力区;开裂顶头中加入了Fe、Mn、Si等合金元素,这些元素的存在会直接或间接提高顶头的脆性,Ti、Zr元素的氧化物会降低顶头力学性能;在高温复杂应力环境下,钼合金顶头表面的孔洞或夹杂物处会率先生成裂纹,随后裂纹沿着晶界开裂,继而向顶头内部延伸。Analyzed in the paper are the reasons for surface cracking of the Mo alloy plug as occurring when it is being used to pierce the high Ni-Cr stainless steel.And an analysis is conducted via a comparison with the normal plug.As a result,it is identified that the said cracking of the Mo alloy plug is a kind of fatigue cracking,and the crack source area is located in the complex stress area on the surface of the piercing cone of the Mo alloy plug;since certain alloy elements,i.e.,Fe,Mn and Si are added to the cracked plug,the brittleness of the plug shall be increased by these elements directly or indirectly,and the oxides of Ti and Zr shall get the mechanical properties of the plug reduced;and under the condition of the hi-temperature complex stress,cracks first develop in the surface areas where holes or inclusions exist,and then the cracks continuously develop along the crystal boundaries,and further extend towards the inside of the plug.

关 键 词：穿孔 钼合金 顶头 夹杂物 热疲劳开裂 

分 类 号：TG146.412[一般工业技术—材料科学与工程]