Effects of preheating-induced interlaminar microstructural evolution on performance of fiber laser welded high strength low alloy steel

• DOI: 10.1016/j.jmrt.2021.12.010
• Publication Date: 2021-12-08T17:05:15Z
• Authors: Chongjing Hu; Lin Chen; Xiong Zhang; Gaoyang Mi; Chunming Wang
• Keywords: Butt joint

In this study, the induction preheating was adopted to improve microstructure and performance of high strength low alloy steel butt joints with 20 mm thickness. The could effectively change thermal cycles interlaminar zones, which beneficial restrain formation martensite inhibit microstructural inhomogeneity. As temperature increased, cooling rates zones slowed down. a consequence, time for carbon diffusion outward austenite transformation inhibited ferrite promoted in zone, led remarkable decrease amount martensite–ferrite interfaces. fluctuation hardness smoothed due elimination martensite. Cracks occurred at interfaces under cyclic stresses were greatly reduced, resulted significant increase fatigue life welded joint. Galvanic reactions caused by different potentials restrained, decreased corrosion enhanced resistance joints.