氢气压缩机出口缓冲罐小接管裂纹失效分析

Analysis of small nozzle crack in hydrogen compressor outlet buffer tank

某氢气压缩机出口缓冲罐小接管与加强筋板焊缝处存在疑似埋藏裂纹缺陷,通过化学成分分析、常温拉伸试验、宏观分析、金相分析、显微硬度测试、扫描电镜和能谱分析确定开裂原因。结果表明:小接管与加强筋板焊缝的熔敷金属和热影响区存在明显的夹渣、空穴和未熔合,属于制造缺陷,为清根不良和焊接操作不当造成的。建议调整筋板焊接工艺,适当增加焊接电流并降低焊速,加强清根,从而保证焊接质量。

Suspected buried cracks were found at weld seam between a small nozzle of hydrogen compressor outlet buffer tank and stiffener plate.Analysis was conducted by means of chemical composition analysis,room temperature tensile test,macroscopic analysis,metallographic analysis,microhardness testing,scanning electron microscopy and energy spectrum analysis.The tests indicated that there were obvious slag inclusions,cavities,and incomplete fusion in deposited metal and heat affected zone of welds between nozzle and stiffener plate,which were manufacturing defects caused by poor root cleaning and improper welding.Solutions were proposed to ensure welding quality,such as adjusting welding procedure of stiffener plate,appropriately increasing welding current,reducing welding speed and strengthening root cleaning.