The quality control of large-caliber seamless pipe
The quality control of large-caliber seamless pipe is not only the safe operation of production, but also the necessary factor to ensure the safety of operators. The application fields are mainly in large-span grid engineering, building steel structure engineering, power and ultra-high voltage transmission and distribution engineering, mechanical engineering, sea-crossing bridge, bridge, (railway station, airport, stadium steel structure engineering), municipal pipeline network, foundation piling, water gas pipeline and highway construction and other supporting facilities.
Quality control points:
1. Check whether the specifications of wire and flux are correct according to the welding procedure rules, so as to prevent welding quality accidents caused by misuse of wire and flux.
2. Supervise the welding environment. When the welding environment is not good (temperature below 0 C, relative humidity greater than 90%), the corresponding measures should be taken before welding.
3. Check groove size before pre-welding, including clearance, blunt edge, angle and misalignment.
4. Whether the parameters of welding current, welding voltage and welding speed selected in the process of submerged arc automatic internal and external welding are correct or not.
5. Supervising welders to make full use of the length of the arc-triggering plate at the end of the steel pipe when submerged arc welding inside and outside automatically, and to enhance the efficiency of the arc-triggering plate when welding inside and outside, which will help to improve the quality of end welding.
6. Supervise whether the welder cleans the slag first, whether the joint has been thoroughly treated, and whether there are oil, rust, slag, water, paint and other dirt at the groove.