Abstract: Post-weld residual stress is caused by uneven temperature distribution of weldments during welding and weld metal's expanding with heat and contracting with cold, so residual stress is inevitable during welding. The purpose of post-weld heat treatment is to eliminate the post-weld residual stress in the welded joints. The tensile strength, yield strength and toughness of welded joints are related to the temperature and insulation time of post-weld heat treatment. Taking the chromiummolybdenum heat-resistant A335-P11 steel as an example, this paper tests three different post-weld heat treatment times (675 ℃×3 h, 675 ℃×4.6 h, 675 ℃×7 h) of welded joints made of this material. It analyzes the effects of different post-weld heat treatment insulation time on the performance of welded joints. The analysis results indicate that extending the insulation time of the post-weld heat treatment has little effect on the performance of the welded joints.

Key words: A335 P11, residual stress, post-welding heat treatment, insulation time