INFLUENCE OF WELDING TECHNIQUES ON MICROSTRUCTURE AND HARDNESS OF STEEL JOINTS USED IN AUTOMOTIVE AIR CONDITIONERS

Metallurgy and Foundry Engineering Pub Date : 2017-01-01 DOI:10.7494/MAFE.2017.43.4.281

P. Noga, M. Węglowski, P. Zimierska-Nowak, M. Richert, J. Dworak, J. Rykala

{"title":"INFLUENCE OF WELDING TECHNIQUES ON MICROSTRUCTURE AND HARDNESS OF STEEL JOINTS USED IN AUTOMOTIVE AIR CONDITIONERS","authors":"P. Noga, M. Węglowski, P. Zimierska-Nowak, M. Richert, J. Dworak, J. Rykala","doi":"10.7494/MAFE.2017.43.4.281","DOIUrl":null,"url":null,"abstract":"Austenitic steels belong to a group of special-purpose steels that are widely used in highly aggressive environments due to their enhanced anticorrosive behavior and high mechanical properties. The good formability and weldability of these materials has made them very popular in automotive AC systems. This study presents the results of hardness tests and microstructure observations on plasma- and laser-welded joints. The examined joints consisted of two different stainless steel components; i.e., a nipple made from corrosion-resistant AISI 304 steel and a corrugated hose made from 316L steel. Microplasma welding was carried out on a workstation equipped with an MSP-51 plasma supply system and a BY-100T positioner. The laser-welded joint was made on a numerically controlled workstation equipped with an Nd:YAG laser (without filler material) with 1 kW of maximum power; the rotational speed of the welded component was n = 4 rpm. Microstructural observations were performed using a scanning electron microscope and an optical microscope. Vickers hardness was measured with a hardness tester. The obtained results proved that both the microplasma- and laser-welded joints were free from any visible welding imperfections. In the micro areas of the austenitic steel weld, crystals of intercellular ferrite appeared against a background of austenite. The crystallization front (depending on the welding technology) was running from the fusion line towards the weld axis. The grain size depended on the distance from the fusion line.","PeriodicalId":18751,"journal":{"name":"Metallurgy and Foundry Engineering","volume":"7 1","pages":"281"},"PeriodicalIF":0.0000,"publicationDate":"2017-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Metallurgy and Foundry Engineering","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.7494/MAFE.2017.43.4.281","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}

引用次数: 2

Abstract

Austenitic steels belong to a group of special-purpose steels that are widely used in highly aggressive environments due to their enhanced anticorrosive behavior and high mechanical properties. The good formability and weldability of these materials has made them very popular in automotive AC systems. This study presents the results of hardness tests and microstructure observations on plasma- and laser-welded joints. The examined joints consisted of two different stainless steel components; i.e., a nipple made from corrosion-resistant AISI 304 steel and a corrugated hose made from 316L steel. Microplasma welding was carried out on a workstation equipped with an MSP-51 plasma supply system and a BY-100T positioner. The laser-welded joint was made on a numerically controlled workstation equipped with an Nd:YAG laser (without filler material) with 1 kW of maximum power; the rotational speed of the welded component was n = 4 rpm. Microstructural observations were performed using a scanning electron microscope and an optical microscope. Vickers hardness was measured with a hardness tester. The obtained results proved that both the microplasma- and laser-welded joints were free from any visible welding imperfections. In the micro areas of the austenitic steel weld, crystals of intercellular ferrite appeared against a background of austenite. The crystallization front (depending on the welding technology) was running from the fusion line towards the weld axis. The grain size depended on the distance from the fusion line.

查看原文本刊更多论文

焊接工艺对汽车空调用钢接头显微组织和硬度的影响

奥氏体钢是一类特殊用途的钢，由于具有较强的抗腐蚀性能和较高的力学性能，在高腐蚀环境中得到了广泛的应用。这些材料具有良好的成形性和焊接性，在汽车交流系统中非常受欢迎。介绍了等离子体和激光焊接接头的硬度测试和显微组织观察结果。所检查的接头由两种不同的不锈钢部件组成;即，由耐腐蚀的AISI 304钢制成的接头和由316L钢制成的波纹软管。在配备MSP-51等离子体供应系统和BY-100T定位器的工作站上进行微等离子体焊接。采用最大功率为1 kW的Nd:YAG激光器(无填充材料)，在数控工作台上制作激光焊接接头;焊接构件的转速为n = 4rpm。采用扫描电子显微镜和光学显微镜进行显微结构观察。用硬度计测定维氏硬度。结果表明，微等离子体和激光焊接接头均无明显的焊接缺陷。在奥氏体钢焊缝的微观区域，在奥氏体背景下出现了胞间铁素体晶体。结晶前沿(取决于焊接技术)从熔合线走向焊接轴。晶粒大小取决于与熔合线的距离。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Metallurgy and Foundry Engineering

自引率

0.00%

发文量