Int J Performability Eng ›› 2019, Vol. 15 ›› Issue (7): 1905-1911.doi: 10.23940/ijpe.19.07.p17.19051911

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7A52 Aluminum Alloy MIG Welding Residual Stress Reliable Measurement based on Hole-Drilling Method

Shiming Gana,b, Yongquan Hanb,*, and Xiaoyan Baoa,b   

  1. a College of Mechanical Engineering, Inner Mongolia University of Technology, Hohhot, 010051, China
    b Materials Forming Key Laboratory, Inner Mongolia University of Technology, Hohhot, 010051, China
  • Submitted on ;
  • Contact: * E-mail address: 447172542@qq.com
  • About author:Shiming Gan is a doctoral candidate at Inner Mongolia University of Technology. His research interests include welding residual stress tests.Yongquan Han is a professor at Inner Mongolia University of Technology. His research interests include new welding processes and automation.Xiaoyan Bao is a doctoral candidate at Inner Mongolia University of Technology. Her research interests include welding heat source simulation.
  • Supported by:
    This work is supported by the National Science Foundation of China (No. 51665044).

Abstract: To analyze the welding residual stress distributions for aluminum alloy medium and thick plates after the process of MIG welding, a residual stress testing system based on hole-drilling method was designed by virtual instrument and NI data acquisition card. To improve the accuracy and reliability of measurement results, the elasticity modulus error, strain gauge pasted error, and strain reading value time error were emphatically analyzed. The elasticity modulus error could be corrected by the curve that is fit to data measured in different MIG welding joint areas. The final measurement error caused by the strain gauge pasted error was reduced to 0 in 24 hours after the strain gauge was pasted. The final measurement error caused by the strain reading value time error was reduced to 0 in 150 minutes after the residual stress began to be measured. The experiment of MIG welding residual stress measurement was carried out on 10 mm thick 7A52 aluminum alloy plates. The results showed that the distributions of residual stresses on two sides of the weld seam were basically symmetrical about the weld center. The maximum tensile stress appeared in the fusion zone, and the maximum transverse residual stress and the maximum longitudinal residual stress were 96 MPa and 185 MPa, respectively. The residual stresses from the fusion zone to heat affected zone were all tensile stresses, which were higher than the residual stresses in the center of the welding seam. Smaller compressive stresses appeared in the base metal.

Key words: residual stress measurement, error analysis, metal inert gas welding, hole-drilling method