▎ 摘　　要

NOVELTY - Welding and heat treatment of P91 high temperature steel pipeline involves preparing the to-be-welded position of P91 high temperature steel pipeline to be processed in high altitude for processing groove processing, preheating the thermocouple symmetrically distributed before welding, and the thermocouple close to the P91 high temperature steel pipeline of the slope, preheating at 150-200 degrees C, inserting the bottom layer welding from the groove gap or flaw detection hole into the charging needle to P91 high temperature steel pipeline for argon protection, to be internal emptying air, then performing argon arc welding bottom welding, when the preheating temperature reaches a predetermined temperature, performing backing welding, ensuring the root fusion is good, and using internal wire feeding method. USE - P91 high-temperature steel pipeline welding and heat treatment method. ADVANTAGE - The method has simple technique, good welding effect and good comprehensive mechanical performance of the welding joint. DETAILED DESCRIPTION - Welding and heat treatment of P91 high temperature steel pipeline involves preparing the to-be-welded position of P91 high temperature steel pipeline to be processed in high altitude for processing groove processing, preheating the thermocouple symmetrically distributed before welding, and the thermocouple close to the P91 high temperature steel pipeline of the slope, preheating at 150-200 degrees C, inserting the bottom layer welding from the groove gap or flaw detection hole into the charging needle to P91 high temperature steel pipeline for argon protection, to be internal emptying air, then performing argon arc welding bottom welding, when the preheating temperature reaches a predetermined temperature, performing backing welding, ensuring the root fusion is good, and using internal wire feeding method, welding rod electric arc welding filling, covering layer welding after finishing welding, where the pre-heating temperature is set at 200-250 degrees C, starting multi-step electric arc welding, and each time welding layer thickness is not more than 4 mm, after welding the outer surface of the welding seam, checking if it is found that the outer surface does not reach the expected effect, before cooling the welding seam, performing repair welding, and after welding heat treatment, heating temperature of the P91 high temperature steel pipeline is 300-350 degrees C, the constant temperature time is 2 hours after welding heat treatment.