External rotor motor fan much higher
The raw material steel plate (coil) of ERW welded pipe is made of low-carbon microalloy steel rolled by TMCP (Thermo-Mechanical Control Process). Tensile testThe tensile performance indexes of seamless steel pipes and ERW steel pipes conform to API standards, but the strength of seamless steel pipes is generally at the upper limit and the plasticity is at the lower limit. 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.9. Blasting testThe blasting test performance of ERW steel pipe is external rotor motor fan much higher than the standard requirement, mainly due to the high uniformity of wall thickness and uniform outer diameter of ERW steel pipe.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%.B Welded refers to the material Welded steel pipe of API 5L GR.6. In comparison, the strength index of ERW steel pipes is in the best state, and the plasticity index is 33.Because ERW's current casing steel grade can only be controlled at the highest K55, if the steel grade is higher, China does not have this production capacity. The process temperature is basically constant at room temperature, so the outer diameter control is accurate and the fluctuation range is small, which is helpful to eliminate black leather buckles;2.3% higher than the standard.ASTM A53 Grade B is the material under the American steel pipe standard, API 5L Gr. The raw material composition, cooling condition and cooling state of the roller have a great influence on its outer diameter, so the outer diameter control is difficult to be accurate and fluctuates The range is larger.B is also the American standard material, A53 GR.The reason is that the performance of hot-rolled coils, the raw material of ERW steel pipes, is guaranteed by means of microalloying smelting, out-of-furnace refining, and controlled cold and controlled rolling; seamless steel pipes mainly rely on means to increase carbon content, which is difficult to ensure strength and plasticity.5. There are no welds on the pipe body itself.Seamless steel tubes refer to steel tubes manufactured by four methods: hot rolling, cold rolling, hot drawing, and cold drawing. The surface quality of the coils axial fan is the surface quality of ERW steel pipes.11. The surface quality of hot-rolled coils is easy to control and high in quality. Straight seam welded pipe has simple production process, high production efficiency, low cost and rapid development. The process can reach a certain level, but it can only be produced to N80. The subsequent hot rolling can partially eliminate the unevenness of the wall thickness, but the most advanced unit can only be controlled within ±5~10%t.
