Research Progress on Welding Technology and Joint Microstructure for 690MPa Low-Alloy High-Strength Steel
The low-alloy high-strength tempering steel with yield strength of 690 MPa has broad engineering application prospects.Cold crack,softening or embrittlement of heat affected zone,and local embrittlement of weld metal are the common problems for the high-strength tempering steel during welding production.Understanding the microstructure evolution of high-strength steel and developing high-efficient and high-quality welding technology are important to ensure the safe application of 690 MPa high-strength steel in large engineering structures.The optimization of welding process and the exploration of new welding methods of the high-strength steel in recent years were investigated.The latest research progress on the microstructure evolution of heat affected zone and weld metal of 690 MPa high-strength steel was summarized.