Publish Time: 2020-06-04 Origin: Site
Welding rotators are important in large steam turbine so welding rotators have very strict quality requirements.This article will introduce how to control the quality of welding rotator.
Welding rotator process quality control
Welding groove of welding rotator assembly
Preheating and process insulation of welding rotator before welding
Welding process of welding rotator
Post welding heat treatment of welding rotator
Post-welding inspection of welding rotator
Welding rotator is large in size and heavy in mass, and process quality control becomes more complex and difficult.Saic has carried out process test exploration for circular analog parts with the same size of welding rotator and verified the manufacturing process, forming a quality control system for welding rotator process.
Due to the larger size and increased quality of welding rotator, welding assembly becomes more difficult, so special tooling is needed to complete the assembly of welding wheel. Therefore, special lifting tooling for low-voltage welding rotor of nuclear power is designed for assembly.The machining precision of welding rotator groove and the strict assembly process ensure the requirement of welding rotator assembly coaxiality.
Welding rotator forgings made of NiCrMoV steel are required to be welded at a certain preheating temperature to prevent the formation of specific cold cracks due to their cold crack sensitivity.Saic uses induction heating to preheat and keep warm the whole rotor, and ensures the overall uniformity of the welding rotator temperature by controlling the temperature in different regions.
Welding rotator root welding requires single welding and double welding to form, so whether the first welding seam can melt through directly relates to whether the quality of welding seam can meet the requirements.During hydrogen arc welding, the welding position is horizontal welding, and 100% penetration of root weld is realized through accurate process control.Submerged arc welding filling is full automatic welding process, the welding position is flat welding, control the wire dry elongation, welding speed and interlayer temperature, ensure the welding quality.All welding processes are documented, including paper and electronic documentation, to ensure traceability of welding rotator processes.
After welding rotator is finished, post welding heat treatment is carried out in large well type heat treatment furnace.Reasonable heat treatment process ensures that the residual stress in welding rotator and welding zone is at a low level and has good comprehensive mechanical properties.By monitoring the temperature of the rotor at different positions, the heat treatment process after welding can meet the requirements.
After welding rotator post-weld heat treatment, ultrasonic sweep and magnetic particle test was carried out on the welding seam area to verify the quality of the weld.The inspection and acceptance criteria are developed to meet the design requirements of the rotor.The assurance and control of welding quality is an important link in the quality assurance system of nuclear power construction. The development of welding technology and the application of new technology will improve the overall manufacturing technology level of nuclear power key equipment, further improve the welding quality and welding efficiency of nuclear power equipment, and also provide a solid foundation for the improvement and optimization of design technical conditions.
We hope this article is helpful to you. Our company specializes in welding rotators. If you need welding rotators, please contact us.