Outer diameter toleranceERW steel pipe: It is cold-formed and sizing is completed by reducing the diameter by 0. The surface quality of the hot rolled coil is easy to control and the quality is high.7mm series oil and casing. Part of this oil production area belongs to sulphur-bearing, low-temperature wells and high anti-crushing geological conditions. ERW steel pipe uses hot rolled coil as the raw material. Its wall thickness uniformity and ellipticity are far superior to seamless steel tubes, which are the main reasons why the crush resistance is higher than seamless steel pipes. Therefore, in the same specifications and the same weight of the casing, ERW steel pipe is 5-10% longer or even more than the seamless steel pipe, which reduces the steel consumption of 10,000 meters footage 5-10%.Seamless steel pipe: The limit of wall thickness control accuracy is 0. 12. In comparison, the strength of ERW steel pipes is at its best and the plasticity index is 33. The process temperature is basically constant at room temperature.

StraightnessERW steel pipe is cold-worked, and has on-line straightening in the state of reduced N06625 Inconel tube manufacturers diameter, plus an infinite multiple rule, so the straightness is better; seamless steel pipe is formed in a plastic state, plus a single rule (continuous rolling is 3 ~ 4 times rule) Tube straightness is relatively difficult to control.05mm, and seamless steel pipes are produced by round steel perforation, with large wall thickness deviations. The P110 steel graded ladder buckle type casing went down to a depth of 5400m.6 tons per 10,000 meters, and save an average cost of 300,000 yuan. The surface quality of the coil is the surface quality of the ERW steel pipe.Taking 9-5  8 * 8.com. Therefore, the outer diameter is controlled accurately and the fluctuation range is small, which is helpful to eliminate black leather buckles.2.10.5. The depth of N80 steel-grade oil and casing pipe running is about 4800m.

The domestic oilfields are mainly North China oilfields and Daqing oilfields. By controlling the impurity content of raw materials, the height and direction of longitudinal burrs, the shape of the forming edge, the welding angle, and the welding speed , Heating power and frequency, welding extrusion amount, intermediate frequency withdrawal temperature and depth, air cooling section length and other process parameters ensure that the impact energy of the weld reaches more than 60% of the base metal, if further optimized, it can achieve the impact energy of the weld close to the mother MaterialAchieve seamless performance.9. Hardness.

The raw material of the ERW steel pipe, the hot-rolled strip coil, has a high precision of controlled cooling and rolling during the rolling process, which can ensure the uniform performance of each part of the strip coil.72mm casing was also used in the Texas oil field in the United States, and the same effect was obtained. Impact testBecause the impact toughness of ERW steel pipe base material is several times that of seamless steel pipe, the impact toughness at the weld is the key to ERW steel pipe.7x7. So far, no quality problems have occurred in the use of the product. Thickness non-uniformity, but currently the most advanced units can only be controlled within + 5 ~ 10% t, corresponding to steel tubes with a thickness of 8. The subsequent hot rolling can partially eliminate the wall thickness. The P110 steel graded ladder buckle type.