Baskutis Saulius, Baskutiene Jolanta, Bendikiene Regita, Ciuplys Antanas, Dutkus Karolis
Department of Production Engineering, Faculty of Mechanical Engineering and Design, Kaunas University of Technology, Studentu Str. 56, LT-51424 Kaunas, Lithuania.
Umega Group AB, Kauno Str. 120, LT-20115 Ukmerge, Lithuania.
Materials (Basel). 2021 Oct 18;14(20):6180. doi: 10.3390/ma14206180.
The present study utilized a metal inert gas welding (MIG) to make a dissimilar weld of stainless steel AISI 304, 314, 316L, 420 grades and a standard structural steel S355MC. It refers to a weld joining two materials from different alloy systems commonly used in heat exchangers, pressure vessels, and power plant systems. Obviously, maintaining the integrity of such welds is of paramount importance to the safety issues. Therefore, detailed microscopic and experimental studies were performed to evaluate the reliability of these welds. The microscopic analysis did not reveal any presence of weld defects such as porosity or cracks, which ensured that MIG process parameters were properly selected. The performance of dissimilar welds was assessed by hardness and tensile tests. The hardness profiles revealed differences between austenitic and martensitic steel welds that later showed extremely high values in the heat-affected zone (HAZ), which caused fractures in this zone during tensile test. The welds of all austenitic steel grades withstood the tensile test, showing an average tensile strength of 472 MPa with fractures observed in the base metal zone. It made clear that the use of a filler rod 308LSI is suitable only for the austenitic stainless and structural steel dissimilar welds and not appropriate for martensitic-structural steel welds. The achieved results revealed that the higher hardness of the martensitic phase in the HAZ of AISI 420 is closely related with the formation of untempered coarse martensitic structure and higher carbon content.
本研究采用金属惰性气体保护焊（MIG）对AISI 304、314、316L、420级不锈钢和标准结构钢S355MC进行异种焊接。它指的是将两种常用于热交换器、压力容器和发电厂系统的不同合金体系的材料焊接在一起。显然，保持此类焊缝的完整性对安全问题至关重要。因此，进行了详细的微观和实验研究以评估这些焊缝的可靠性。微观分析未发现任何诸如气孔或裂纹等焊接缺陷，这确保了MIG工艺参数的正确选择。通过硬度和拉伸试验评估异种焊缝的性能。硬度分布显示奥氏体和马氏体钢焊缝之间存在差异，随后在热影响区（HAZ）显示出极高的值，这导致在拉伸试验期间该区域出现断裂。所有奥氏体钢级别的焊缝都通过了拉伸试验，在母材区观察到断裂，平均抗拉强度为472 MPa。这表明使用填充焊丝308LSI仅适用于奥氏体不锈钢与结构钢的异种焊缝，不适用于马氏体 - 结构钢焊缝。所取得的结果表明，AISI 420热影响区马氏体相的较高硬度与未回火的粗大马氏体组织的形成以及较高的碳含量密切相关。
Zotero 插件
