Welded steel pipe
is a hot-rolled coil after molding machine, the use of high-frequency current skin effect and proximity effect, so that the edge of the tube is heated to melt under the action of squeezing rollers pressure welding to achieve production.
High frequency resistance welding method used in pipe production of the 1950s. Over the past decade, the production technologies are maturing, continuously improve product quality.
First, ERW steel pipe used in the production of raw material quality has been significantly improved, the steel component design of the low C, low P, S, micro-alloying; smelting process smelting, ladle refining, vacuum degassing, continuous casting and other new using technology; ERW pipe - ERW rolling process controlled rolling, controlled cooling technology enables the use of medium and large caliber ERW steel pipes hot strip appearance of size, appearance quality, physical and chemical properties greatly improved. On behalf of my hot strip highest level of Baoshan Iron and Steel Company production of steel pipeline has reached the American Petroleum Institute API 5L standards, at the international level.
Followed by medium and large diameter ERW Longitudinal molding welding and heat treatment step in the production process to achieve a computer automatic control, high-frequency welding process heat input energy with the automatic compensation system of the computer has been effectively controlled to prevent the welding heat input energy cold welding caused low, Weld heat input and high energy caused by over-burning. IF heat treatment temperature control allows heat treatment process can achieve the best results according to process requirements, to effectively guarantee the quality of the steel pipe weld and heat affected zone.
In addition, ERW Pipe - ERW detection technology progress, to achieve a full online or offline ultrasonic or eddy current weld adventure injury, the hydrostatic test may be under the supervision of a computer, as required for pressure testing and regulation. Promotion and implementation of the ISO9000 series of standards and norms APIQ1, making medium and large caliber ERW straight seam steel pipe production, testing, sales and service in a whole process of quality assurance among.
In recent years, countries are actively using ERW straight seam welded steel pipe
and spiral welded pipe seamless tube in place, in industrialized countries, ERW straight pipe diameters Ф610mm less, ERW steel pipe has reached the proportion of about 70%. Our production capacity of ERW Longitudinal also constantly enhanced.