Fracture toughness of martensitic stainless steel resistance spot welds
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- 作者：M. Pouranvari pouranvari@sharif.edu
- 关键词：Resistance spot weld ; Martensitic stainless steel ; Fracture toughness ; Failure mode
- 刊名：Materials Science and Engineering: A
- 出版年：2017
- 出版时间：5 January 2017
- 年：2017
- 卷：680
- 期：Complete
- 页码：97-107
- 全文大小：1932 K
- 卷排序：680
文摘
The paper is focused on the strength and fracture toughness of AISI420 martensitic stainless steel resistance spot welds under the tensile-shear loading. The failure behavior of AISI420 spot welds was featured by quasi-cleavage interfacial failure with low load bearing capacity and weak energy absorption capability which was a function of the weld fusion microstructure, predominately carbon and chromium rich martensite plus δ-ferrite. Fracture toughness of the fusion zone proved to be the most important factor controlling the peak load of the spot welds made on AISI420 failed in interfacial mode. A geometry-independent fracture toughness of the weld nugget (c.a. 23 MPam0.5) was determined using fracture mechanics concept. Through modeling it was found that there is a critical fracture toughness which beyond that the pullout failure mode can be obtained which is a function of sheet thickness and tensile strength of the base metal.