Neutron Diffraction Evaluation of Near Surface Residual Stresses at Welds in 1300 MPa Yield Strength Steel

Materials

Lars-Erik Svensson¹  Ebrahim Harati¹  Leif Karlsson¹  Kamellia Dalaei²  Thilo Pirling³ 

[1] Department of Engineering Science, University West, SE-461 86 Trollhättan, Sweden;ESAB AB, Lindholmsallen 9, 40227 Gothenburg, Sweden;Institut Max von Laue-Paul Langevin, 6 rue Jules Horowitz, BP156, F-38042 Grenoble, France;

关键词: residual stress;    high strength steel;    neutron diffraction;    weld toe;    low transformation temperature welding consumable;   

DOI  :  10.3390/ma10060593

来源: DOAJ

【 摘 要 】

Evaluation of residual stress in the weld toe region is of critical importance. In this paper, the residual stress distribution both near the surface and in depth around the weld toe was investigated using neutron diffraction, complemented with X-ray diffraction. Measurements were done on a 1300 MPa yield strength steel welded using a Low Transformation Temperature (LTT) consumable. Near surface residual stresses, as close as 39 µm below the surface, were measured using neutron diffraction and evaluated by applying a near surface data correction technique. Very steep surface stress gradients within 0.5 mm of the surface were found both at the weld toe and 2 mm into the heat affected zone (HAZ). Neutron results showed that the LTT consumable was capable of inducing near surface compressive residual stresses in all directions at the weld toe. It is concluded that there are very steep stress gradients both transverse to the weld toe line and in the depth direction, at the weld toe in LTT welds. Residual stress in the base material a few millimeters from the weld toe can be very different from the stress at the weld toe. Care must, therefore, be exercised when relating the residual stress to fatigue strength in LTT welds.

【 授权许可】

Unknown