硬质合金与钢电子束焊接接头缺陷及断裂分析
发布时间：2018-08-17 15:13
【摘要】：对WC-Co/40Cr进行电子束焊接试验,研究了焊缝和界面组织,同时分析了焊缝中裂纹的产生机理.结果表明,焊缝主要由马氏体和脆性η相组成,在组织和拉应力作用下生成两种典型裂纹缺陷,一类为冷却过程中尚未凝固的液态薄膜不能填充间隙产生的结晶裂纹;一类为较大残余拉应力使得焊缝中硬脆相开裂形成的淬硬脆化裂纹.界面由于元素扩散作用产生贫碳环境,在合适的温度梯度下会有η相包络生成.测试接头的力学性能,发现接头平均抗剪强度为506 MPa,断裂贯穿于硬质合金热影响区、界面、焊缝处,分别呈现沿晶断裂、准解理断裂和解理断裂的特征.
[Abstract]:Electron beam welding (EBW) of WC-Co/40Cr was carried out to study the weld and interfacial microstructure, and the mechanism of crack formation in the weld was analyzed. The results show that the weld is mainly composed of martensite and brittle_phase. Under the action of microstructure and tensile stress, two kinds of typical crack defects were formed. One is that the liquid film which has not been solidified during cooling can not be filled. Crystalline cracks formed by filling gaps; hardening embrittlement cracks formed by cracking of hard and brittle phases due to large residual tensile stress in weld seams. Carbon-poor environment is produced at the interface due to element diffusion, and_phase envelope is formed at suitable temperature gradient. Intergranular fracture, quasi-cleavage fracture and cleavage fracture occur at the HAZ, interface and weld of cemented carbide.
【作者单位】： 哈尔滨工业大学先进焊接与连接国家重点试验室;
【基金】：国家自然科学基金资助项目(51375115)
【分类号】：TG456.3
本文编号：2188043
[Abstract]:Electron beam welding (EBW) of WC-Co/40Cr was carried out to study the weld and interfacial microstructure, and the mechanism of crack formation in the weld was analyzed. The results show that the weld is mainly composed of martensite and brittle_phase. Under the action of microstructure and tensile stress, two kinds of typical crack defects were formed. One is that the liquid film which has not been solidified during cooling can not be filled. Crystalline cracks formed by filling gaps; hardening embrittlement cracks formed by cracking of hard and brittle phases due to large residual tensile stress in weld seams. Carbon-poor environment is produced at the interface due to element diffusion, and_phase envelope is formed at suitable temperature gradient. Intergranular fracture, quasi-cleavage fracture and cleavage fracture occur at the HAZ, interface and weld of cemented carbide.
【作者单位】： 哈尔滨工业大学先进焊接与连接国家重点试验室;
【基金】：国家自然科学基金资助项目(51375115)
【分类号】：TG456.3
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