Study on microstructure and mechanical characteristics of low-carbon steel and ferritic stainless steel joints
Study on microstructure and mechanical characteristics of low-carbon steel and ferritic stainless steel joints
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DOI：
10.1016/j.msea.2014.04.065
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发表时间：
2014-07-01
期刊：
影响因子：
6.4
通讯作者：
Kokabi, Amir Hossein
中科院分区：
文献类型：
--
作者：
Khorrami, Mahmoud Sarkari;Mostafaei, Mohammad Ali;Kokabi, Amir Hossein
在这项工作中，对普通碳钢和 AISI 430 铁素体不锈钢异种焊缝的显微组织和机械性能进行了检查。通过气体保护钨极电弧焊工艺，在自熔焊和使用 ER309L 奥氏体焊条条件下进行焊接。结果表明，自熔焊缝和添加填料的焊缝分别形成全铁素体和双相铁素体-马氏体显微组织。 AISI 430 钢的热影响区 (HAZ) 会发生碳化物析出、铁素体晶界处马氏体（晶间马氏体）的形成以及晶粒长大。研究发现，焊接热输入会强烈影响晶粒长大现象以及碳化物和晶间马氏体的数量和成分。使用填充金属时焊缝获得的机械特性明显高于自焊焊缝。因此，通过添加填充金属，焊缝金属的极限抗拉强度（UTS）、硬度和拉伸试验吸收能分别从662 MPa提高到910 MPa，从140 Hv提高到385 Hv，从53.6J M-3提高到79J m(-3)。从断口来看，填充金属焊接的试样主要发生延性断裂，而自焊缝金属主要发生解理断裂。 (C) 2014 Elsevier B.V. 保留所有权利。
In this work, examinations on the microstructure and mechanical properties of plain carbon steel and AISI 430 ferritic stainless steel dissimilar welds are carried out. Welding is conducted in both autogenous and using ER309L austenitic filler rod conditions through gas tungsten arc welding process. The results indicate that fully-ferritic and duplex ferritic-martensitic microstructures are formed for autogenous and filler-added welds, respectively. Carbide precipitation and formation of martensite at ferrite grain boundaries (intergranular martensite) as well as grain growth occur in the heat affected zone (HAZ) of AISI 430 steel. It is found that weld heat input can strongly affect grain growth phenomenon along with the amount and the composition of carbides and intergranular martensite. Acquired mechanical characteristics of weld in the case of using filler metal are significantly higher than those of autogenous one. Accordingly, ultimate tensile strength (UTS), hardness, and absorbed energy during tensile test of weld metal are increased from 662 MPa to 910 MPa, 140 Hv to 385 Hv, and 53.6J M-3 to 79J m(-3), respectively by filler metal addition. From fracture surfaces, predominantly ductile fracture is observed in the specimen welded with filler metal while mainly cleavage fracture occurs in the autogenous weld metal. (C) 2014 Elsevier B.V. All rights reserved.