Heat input effects on mechanical constraints and microstructural constituents of MAG and laser 316L austenitic stainless-steel welded joints

AIMS Materials Science

Francois Njock Bayock¹  Paul Kah²  Kibong Marius Tony³ 

[1] 1. Department of Mechanical Engineering, ENSET Douala, University of Douala, P.O. Box: 1872, Douala, Cameroon;2. Department of Engineering Science, University West, Gustava Melius gata 2 S-461 32 Trollhättan, Sweden;3. Laboratory of Technologies and Applied Sciences, University Institute of Technology, University of Douala, PO Box 8698 Douala, Cameroon;

关键词: heat input;    angular distortion;    hot cracking;    microstructural constituent longitudinal distortion;    316l stainless steel;    sem;    eds microscopy;   

DOI  :  10.3934/matersci.2022014

来源: DOAJ

【 摘 要 】

This study aims to investigate the optimum heat input required to overcome the negative consequence of the thermal properties of austenitic stainless steel to produce welded joints free of distortion. An experimental investigation using robotic-MAG and fiber-laser welding processes has been used in other to investigate angular, longitudinal distortion (bending), and microstructural constituents in the heat-affected zone (HAZ) of different welded joints. Ten 316L steel, butt-joints were made by different travel 25 speeds at the range of (7–11 mm/s). A highly sensitive 2D-laser device has been used to measure the distortion then, a microstructural investigation was done using an optical micrograph, Scanning Electron Microscopy (SEM) coupled with the Electron Dispersive Spectrometer (EDS). The laser-fiber welding process results indicated optimum parameters to prevent distortion when applying welding speed of 2.2 m/min, the power source of 2.5 kW, and the focal position of 3 mm. In MAG welding, test results revealed an increase of longitudinal distortion (bending) from 1.2 mm to 3.6 mm when raising the heat input from 0.3 to 0.472 kJ/mm. When increases welding speed (11 mm/s), angular distortion was approximately 2.1° on the left side and 1.7° on the right side. Microstructural investigations revealed the proportionality between heat input and carbides formations on the grain boundaries of HAZ. They were also the formation of etching pores and some ferrite content (10%) on the weld center.

【 授权许可】

Unknown