Welding inspection work should be run through the whole process of product manufacturing, from the the welding preparation work to the non-destructive testing of welds after welding, welding inspection, not only is to identify the presence of various welding defects in the welded joint, and press technical standards to judge and deal with more important welding the whole production process is under control, according to the requirements of the relevant technical documentation and quality management system, excessive weld defects detected in the production process.
Ready to check before welding
The purpose of preparation before welding the first hurdle of the good quality of welding, check the main content: welder qualification tests; confirmation of Welding Materials; intact welding equipment, welding workpiece preparation and assembly inspection.
Welding process checks
Check the preheat temperature
When the welded joints of alloy steel, welded joints need to be preheated. Warm-up is one of the main measures to prevent cold cracking in welded joints, preheat temperature is one of the main parameters of welding procedure provisions should be strictly enforced.
Inspection of the welding process parameters
Boiler welding, Welding Assembly must debug and check, and check whether the process parameters to meet the requirements of the welding procedure. Welding, should do the welding construction records.
After welding quality inspection
After welding quality inspection is the final step of welding inspection, usually after all welding work after welding quality inspection include the following:
Macroscopic examination
Welding welders whether at a specified position marked with a own welders code stamp. Check the weld heat affected zone of the appearance of defects, weld width, weld reinforcement Higher compliance requirements, commonly used inspection tools such as weld inspection feet.
Appearance after welding inspection and approval, inspection reports submitted by the inspection department of the boiler plant, confirmed by the supervisory inspector qualified butt the appearance inspection records review confirmed the signing, supervisory inspector when necessary sampling boiler weld appearance.
Non-destructive testing of welds
Weld-ray, ultrasonic nondestructive testing JB/T4370-2005 "pressure equipment and non-destructive testing standards for testing. After welding the weld by the ray, ultrasonic non-destructive testing of qualified boiler factory inspection department will submit rays, ultrasonic testing of welds of nondestructive testing reports and ray negatives mill supervision inspectors, supervisory inspector to cope ray, ultrasonic weld review of the inspection report, carried out at least 30% of spot checks and the ray detection negatives of each boiler products, and were spot-check records confirm the signing and fill NDT, and when necessary, the supervisory inspector NDT personnel in conjunction with the boiler plant to the on-site verification film parts.
Hydrostatic test
The hydrostatic test shall be conducted according to the relevant provisions of the boiler Safety Technology Supervision.
Boiler hydrostatic test Boiler Plant inspection department should advance reported supervisory inspector, supervisory inspector hydrostatic test of the boiler must be 100% of the on-site supervisory inspection, hydrostatic testing qualified supervisory inspector signed hydrostatic test report confirmation.
Weld repair
Need repair welds found in the non-destructive testing, rework process requirements are as follows:
The repair welder should hold welder with the corresponding project certificate
The weld repair shall comply with the relevant provisions of steam, hot water boilers Safety Technology Supervision. The repair welds generally use manual metal arc welding, weld Rework length longer submerged arc welding and other methods can be used, the welding procedure qualification qualified welding process can be used to repair, in rework weld process, in addition to weld the underlying and cap weld, the hammering method may be used to release stress. Weld rework, rework welder should JB/T4308-1999 "boiler products stamp and mark transplantation provides that" the relevant provisions of branded welder stamp. Repair weld quality inspection shall be conducted in accordance with the requirements of the original weld.
Rework on the same seam position shall not be more than three times, each time to rework should fill out the the welded joints rework card ", such as the the second weld repair is still unqualified, should be the workshop welding technicians and other personnel with the first two review the changes of the times to repair defects and the original rework process analysis and develop viable rework program audited by welding responsibility engineers, quality assurance engineers approved only after the third rework.
The supervisory inspection repair welding of boiler links, supervisory inspector should weld repair process single review to confirm: boiler weld repair of non-destructive testing negative for 100% inspection, and good inspection records.