Strain ageing embrittlement behaviour of X80 self-shielded flux-cored girth weld metal
Strain ageing embrittlement behaviour of X80 self-shielded flux-cored girth weld metal
复制标题
X80自保护药芯焊缝金属应变时效脆化行为
DOI：
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发表时间：
2023
期刊：
影响因子：
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通讯作者：
Xueda Li
中科院分区：
文献类型：
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作者：
Lei Guo;X. Su;L. Dai;Leilei Wang;Qiaofei Sun;Chaohai Fan;Yalei Wang;Xueda Li
研究了X80自保护药芯焊丝环焊缝金属在不同应变时效条件（1%预应变，150°C/100°C时效1 ~ 6 h和80°C时效1-30 d）下的应变时效脆化行为。FCAW环焊缝组织主要由粗大粒状贝氏体和板条贝氏体组成。应变时效后，韧性显著下降，时效温度升高或时效时间延长导致韧性下降，直至时效完全屈服。在应变时效初期，韧窝较多，且伴随着解理面。随着应变时效的进行，脆化现象越来越明显，解理面变大，韧窝变少，解理断裂起始点的临界尺寸变小。部分应变时效时，马氏体-奥氏体组元（1-2 μm）可诱发解理断裂，而完全应变时效时，亚微米夹杂物可诱发解理断裂。
ABSTRACT Strain ageing embrittlement behaviour of X80 self-shielded flux-cored arc welding (FCAW) girth weld metal at different strain ageing conditions (1% prestrain, and aged at 150°C/100°C for 1 –6 h, and 80°C for 1–30 days) was studied. Microstructure of FCAW girth weld generally consisted of coarse granular bainite and lath bainite. After strain ageing, toughness notably decreased, and higher ageing temperature or longer ageing induced lower toughness, until ageing is fully yielded. At initial stage of strain ageing, more dimples were found accompanying with cleavage facet. With the progress of strain ageing, the embrittlement was more obvious, while larger cleavage facet and less dimples were found. Meanwhile, the critical size for cleavage fracture initiation site became smaller. Martensite–austenite constituent (1–2 μm) was found to initiate cleavage fracture when partially strain aged, while submicron inclusions could initiate cleavage facet when fully strain aged.