Differences in ERW and SAWL

Straight seam welded steel pipe, according to the welding process can be divided into high-frequency resistance welding and submerged arc welding, longitudinal submerged arc welded is short for SAWL, and high-frequency straight seam resistance welding is short for ERW.

High-frequency resistance welding steel ( ERW steel ) because of its welding and submerged arc welding in the welding process, ERW process does not add any welding materials, welding without heat melting state of weld metal, just after the recrystallization process, the formation of the weld and base material chemical composition completely consistent, steel after annealing treatment, manufacture of cold molding stress, welding stress were improved, therefore the comprehensive mechanical properties of ERW steel pipe.

Longitudinal submerged arc welding ( SAWL steel ) because it uses the welding cold expanding process pipe, so the SAWL pipe dimension precision, using SAWL steel pipe butt counterparts in good quality so as to ensure the welding quality, through expanding technology to some extent by removing a portion of the internal stress. In addition SAWL steel pipe welding multiple wire welding (three wire, the four-wire ), such that the welding process generated when welding line energy is small, the parent material of heat affected zone of influence degree is small.

Multiple wire welding after welding of former wire can rise to eliminate welding stress effect, thus the mechanical properties of steel pipes improvement. The mother can do ultrasonic flaw detection of the plate 100%, and meet the high-pressure pipeline of parent material requirements. Although the SAWL pipe performance is better than other steel tubes, its high price, makes capital tension for the user and step back.

One, raw material and production capacity difference

ERW steel is the raw material of hot rolled steel coils, and SAWL pipe material is a hot rolled steel plate. So ERW steel can achieve continuous assembly line operation, high production efficiency, and low production cost; and SAWL steel plate processing can realize continuous production line operation, low production efficiency, and high production cost.

Two, application difference

ERW pipe is mainly used in natural gas, crude oil, refined oil, pulp, and another terrestrial long-distance transmission pipeline. SAWL steel is mainly applied to the high-voltage undersea pipeline, alpine regions, and land two or three, which are four classes.

Cangzhou Shenlong Pipe Manufacturing Co., Ltd. cooperates with Baosteel and Baogang to produce large-caliber seamless steel pipe, straight-seam welded pipe, spiral steel pipe, and pipe fittings. The products comply with API, ASTM, DIN, BS, and JIS standards, and can accept SGS, BV, and other inspections. The products are used in oil, natural gas, bridge, water conservancy, and other large-scale projects, which are worthy of trust.