Journal of Northeastern University Natural Science ›› 2020, Vol. 41 ›› Issue (2): 208-212.DOI: 10.12068/j.issn.1005-3026.2020.02.010

• Materials & Metallurgy • Previous Articles     Next Articles

Experimental Study on Welding of Q345B/HG785D Steel Plates in Crane Frame

QI Peng-yuan1,2, LIU Jia-qi3, WANG Gang2, LIU Xiang-hua1   

  1. 1. School of Materials Science & Engineering, Northeastern University, Shenyang 110819, China; 2. Department of Materials Science and Engineering, Yingkou Institute of Technology, Yingkou 115014, China; 3. Prototyping Department, Beijing Automotive Off-Road Vehicle Institute, Beijing 101300, China.
  • Received:2019-07-15 Revised:2019-07-15 Online:2020-02-15 Published:2020-03-06
  • Contact: LIU Xiang-hua
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Abstract: Taking butt welding of dissimilar steel plates of Q345B and HG785D as the object, we studied the welding defects, mechanical properties and microstructures of the welded joint by metal active gas(MAG)arc welding under different heat input conditions. It is found that the strength of the welded joint can be improved effectively by reducing welding current in butt welding of dissimilar steel ends. When the joint is preheated before welding and slowly cool down after welding, the quenched hard area in the microstructure is reduced and the toughness of heat affected zone(HAZ)is increased. Under the heat input conditions of 140-200A welding current, 22-24V welding voltage and 28cm/min welding speed, the mechanical and bending properties of the welded joint can be optimized by the process of preheating and post-heat welding. The optimized welding process can inhibit the weld cracking effectively in crane frame.

Key words: Q345B steel, HG785D steel, butt welding of dissimilar steel, MAG welding, welding process, welding quality

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