TP347H不锈钢焊接接头敏化特性分析
Study on sensitization characteristics of TP347H stainless steel welded joints
李乘安 1冯道臣 1章霖 2郑文健 1程茂 3鲁显京 3杨建国1
作者信息
- 1. 浙江工业大学,杭州, 310014
- 2. 一重集团大连核电石化有限公司,大连, 116113
- 3. 浙江省特种设备科学研究院,杭州, 310020
- 折叠
摘要
为明确TP347H不锈钢焊接接头敏化特性,对焊接接头进行不同条件的敏化处理.结果表明,焊接接头热影响区敏化倾向严重,敏化过程中由于Nb原子在晶界上的结合能高于Cr原子,会先形成了粗大的初级铌碳化合物,后形成细小的二次铌碳化合物.在 700℃下保温时,焊接接头热影响区的敏化度呈现先提高后降低的趋势,当温度达到 800℃及以上时,热处理不再提高接头热影响区的敏化度.与实际生产线上服役 21 000 h的F347H接头热影响区敏化特性对比,证实TP347H焊接接头 650℃保温 100 h即可达到敏化极限,其原因是Nb元素含量为C元素的数倍,大部分C元素与Nb元素结合形成NbC,而晶粒中扩散的C元素已与Cr元素充分结合,造成的敏化程度达到平衡状态.
Abstract
In order to clarify the sensitization characteristics of TP347H stainless steel welded joints,the welded joints were heat treated at different temperatures,and the changes of sensit-ization degrees at different temperatures were studied.The res-ults showed that an obvious sensitization trend was observed in the heat-affected zone(HAZ)of welded joints.During the sens-itization process,because the binding energy of Nb atoms on the grain boundary is higher than that of Cr atoms,coarse primary niobium carbon compounds are formed first,and then fine secondary niobium carbon compounds are formed.When the temperature is kept at 700℃,the sensitization degree of the HAZ of the welded joint shows a trend of first increasing and then decreasing.When the temperature reaches 800℃and above,heat treatment no longer increases the sensitization de-gree of the HAZ of the joint.Comparing with the sensitization characteristics of F347H joints with 21 000 h in the actual pro-duction line,it is confirmed that the sensitization limit can be reached by holding the welded joints of TP347H at 650℃for 100 h.The reason is that the content of Nb is several times that of C,most of C combines with Nb to form NbC,and the diffu-sion of C in the grain has been fully combined with Cr.The resulting sensitization reaches an equilibrium state.
关键词
TP347H不锈钢/敏化/焊接接头/热处理/耐蚀性Key words
TP347H stainless steel/sensitization/welded joint/heat treatment/corrosion resistance引用本文复制引用
基金项目
国家自然科学基金资助项目(51705461)
国家自然科学基金资助项目(51975530)
浙江省市场监督管理局雏鹰计划培育项目(CY2022218)
出版年
2024
NETL
NSTL
维普
万方数据