Welded steel pipe refers to the steel pipe with a joint on the surface which is welded after the steel strip or steel plate is bent and deformed into circular, square and other expected shapes. According to different welding methods, it can be divided into arc welded pipe, high frequency or low frequency resistance welded pipe, gas welded pipe, furnace welded pipe, Bondi pipe, A572 grade 55 ms steel coil, etc. According to the weld shape, it can be divided into straight welded pipe and spiral welded pipe. Electric welded steel pipes are mainly used in oil drilling and production, machinery manufacturing, etc.; furnace welded pipes can be used as water gas pipes, large-diameter straight seam welded pipes for high-pressure oil-gas transmission, etc.; spiral welded pipes are used for oil-gas transmission, pipe piles, piers, etc. Welded steel pipe has lower cost and higher production efficiency than seamless steel pipe.
At the same time of doing well in A572 grade 55 ms steel coil production and operation, Yunnan company focused on completing the four phases of technical transformation construction projects, realizing industrial upgrading, improving equipment level, and laying a good foundation for the future development of the company. In the A572 grade 55 ms steel coil technological transformation project, pollution control facilities have been built synchronously, and a large number of comprehensive utilization projects, such as comprehensive sewage treatment and recycling project, blast furnace gas waste heat and residual pressure power generation, have been invested and constructed.
Expression method of pressure coefficient of seamless steel pipe: pressure P < 7MPa coefficient S-8 7 < A572 grade 55 ms steel coil steel pipe pressure P < 17.5, coefficient 5-6 pressure P > 17.5, coefficient S-4 seamless pipe production and manufacturing: tube blank -- Inspection -- peeling -- Inspection -- Heating -- perforation -- pickling -- grinding -- lubrication and air drying -- welding head -- cold drawing -- solution treatment -- pickling -- pickling and passivation -- Inspection -- cold rolling -- degreasing -- air drying -- internal polishing -- one external polishing -- Inspection -- identification of finished A572 grade 55 ms steel coil product packaging.
Weather-resistant steel is atmospheric corrosion-resistant steel. It is a low-alloy steel that has better corrosion resistance in the atmosphere than ordinary carbon steel by adding a small amount of alloy elements. Compared with A572 grade 55 ms steel coil, weathering steel Q355NH, Q355GNHE weathering steel has better resistance to atmospheric corrosion. It is necessary to ensure that the steel plate has high strength and good plasticity and toughness. In addition, by adding a corrosion-resistant element to ensure the atmospheric corrosion resistance index I to reflect its good corrosion resistance.
When providing technical services on site, the after-sales personnel shall strictly abide by the safety rules and regulations of the construction site, consciously take safety protection measures (such as wearing safety helmet when entering the construction site), accept the supervision and management of the site; without permission on the construction site, they shall not dismantle, smear or damage any goods; the commissioning of contract goods shall be carried out under the supervision of the site supervisor If necessary, it shall be approved by the site supervisor or the person in charge of the project department.
