某核电厂楔形闸板阀阀瓣表面司太立合金堆焊层失效分析

IMR OpenIR

	某核电厂楔形闸板阀阀瓣表面司太立合金堆焊层失效分析
其他题名	Failure Analysis of Surface Stellite Alloy Overlayer on Disc of Wedge Gate Valve in a Nuclear Power Plant
	张敏 1; 明洪亮 2; 王凡 1; 张志明 2; 王俭秋 2; 韩恩厚 2; 吕群贤 1
	2019
发表期刊	腐蚀科学与防护技术
ISSN	1002-6495
卷号	31.0 期号:006 页码:622-630
摘要	某核电厂在检修中发现一楔形闸板阀阀瓣两侧表面司太立合金堆焊层密封面发生局部的疑似脱落,堆焊层在服役过程中处于一回路含B和Li的高温高压水环境。本文使用扫描电子显微镜分析了表面堆焊层的微观组织结构,观察了疑似脱落区域的表面与截面形貌,使用能谱系统对局部的化学组成进行了分析。结果表明,表面堆焊层主要发生了开裂,仅局部发生轻微脱落,在堆焊层近表面区域中存在明显的尺寸较大的结晶缩孔型焊接缺陷,以及少量的焊接孔洞和夹杂物。分析认为,由于焊接工艺不当,堆焊层凝固收缩时在内部形成了枝晶间结晶缩孔,局部连续分布,在堆焊层的厚度方向近似呈带状分布,内部焊接缺陷在密封面外力挤压作用下在堆焊层表面显现导致其发生开裂。
其他摘要	The surface Stellite alloy overlayer was found to be locally fallen off from the sealing faces of a wedge gate valve disc in a nuclear power plant.The surface welding overlayer was serviced in high-temperature and high-pressure primary water containing B and Li.The microstructure and chemical composition of the surface welding overlayer,the surface and cross-sectional morphologies of the local fallen area were assessed by scanning electron microscopy equipped with an energy dispersive X-ray spectroscopy(EDS).Results showed that cracks emerged on the Stellite overlayer,while the occurrence of falling off for the overlayer from the sealing faces was only limited in a small area.Obvious and big welding defects of shrinkage cavity during crystallization,and a small amount of welding holes and inclusions were found in the near surface layer of the Stellite overlayer.Improper welding procedure was believed to be the main reason for the formation of shrinkage cavity.These cavities were mainly distributed in the interdendrite,whilst continuous cavities with the characteristics of zonal distribution were nearly perpendicular to the overlayer surface.It is proposed that under the external pressing force of sealing faces,the internal welding shrinkage cavities may be apt to crack,therewith,initiate the cracking of surface overlayer.
关键词	失效分析司太立合金堆焊层阀瓣
收录类别	CSCD
语种	中文
CSCD记录号	CSCD:6646218
引用统计	被引频次：1[CSCD] [CSCD记录]
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/143662
专题	中国科学院金属研究所
作者单位	1.中国广东核电集团大亚湾核电运营管理有限责任公司 2.中国科学院金属研究所
推荐引用方式 GB/T 7714	张敏,明洪亮,王凡,等. 某核电厂楔形闸板阀阀瓣表面司太立合金堆焊层失效分析[J]. 腐蚀科学与防护技术,2019,31.0(006):622-630.
APA	张敏.,明洪亮.,王凡.,张志明.,王俭秋.,...&吕群贤.(2019).某核电厂楔形闸板阀阀瓣表面司太立合金堆焊层失效分析.腐蚀科学与防护技术,31.0(006),622-630.
MLA	张敏,et al."某核电厂楔形闸板阀阀瓣表面司太立合金堆焊层失效分析".腐蚀科学与防护技术 31.0.006(2019):622-630.