By controlling the impurity content of raw materials

Reasonable match.6. HardnessThe raw material of ERW steel pipe, hot-rolled coil, has extremely high precision during the rolling process, which can ensure the uniform performance of all parts of the coil.7. Grain sizeThe raw material of ERW steel pipe-hot-rolled coils are made of wide and thick continuous casting billets, with a thicker fine-grained surface solidification layer, no columnar crystal regions, shrinkage and porosity, small composition deviation, and compact structure; in the subsequent rolling process The application of controlled cold and controlled rolling technology further ensures the grain size of raw materials.8. Anti-collapse testERW steel pipe is due to the characteristics of its raw materials and pipe making process. Its wall thickness uniformity and ellipticity are far superior to seamless steel pipes, China corrugated steel sheet suppliers which is the main reason why the collapse resistance performance is higher than that of seamless steel pipes.9. Impact testSince the impact toughness of the base material of ERW steel pipe is several times that of seamless steel pipe, the impact toughness of the weld is the key to ERW steel pipe.

By controlling the impurity content of raw materials, the height and direction of slitting burrs, the shape of forming edges, the welding angle, and the welding speed , Heating power and frequency, welding extrusion volume, 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, the weld impact energy can be close to the base Material to achieve seamless performance.10. Blasting testThe blasting test performance of ERW steel pipe is much higher than the standard requirement, mainly due to the high uniformity of wall thickness and uniform outer diameter of ERW steel pipe.11.StraightnessThe seamless steel pipe is formed in a plastic state, and the straightness of the pipe end is relatively difficult to control with the single ruler (3 to 4 times ruler for continuous rolling);ERW steel pipe is cold-worked, and it has online straightening in the state of reducing diameter.

In addition, it is infinite times, so the straightness is better.12.The consumption of steel for 10,000-meter footage casingThe wall thickness of ERW steel pipe is uniform, and its wall thickness tolerance can be ignored. The control accuracy limit of seamless steel pipe wall thickness difference is ±5%t, and it is generally controlled at ±5-10%t. In order to ensure that the minimum wall thickness can meet the standard requirements and performance, the solution can only be solved by appropriately increasing the wall thickness. Therefore, in the casing of the same specification and the same weight, the ERW steel pipe is 5-10% longer than the seamless steel pipe, or even more, which reduces the steel consumption of the casing for 10,000 meters by 5-10%. Even at the same price, ERW casing virtually saves users 5-10% of purchasing costs.