ERW steel pipe is a collectively resistance welded steel pipe. According to different frequencies, AC welding can be divided into low frequency welding, soldering IF, IF welding and ultra high frequency welding. High frequenting welding is mainly used for thin walled steel pipe or ordinary steel pipe production. High frequency welding is divided itno contact welding and induction welding. DC welding is generally used for small diameter pipe. Overall, high frequency welded steel pipe is one kind of high frequency welding process of production. ERW steel pipe is widely used in the field of oil and gas strorage and transportation. Meanwhile, ERW steel pipe is widely used for wire casing in the power industry. The performance characteristics including 100% ultrasonic testing of the base material which ensure the inherent quality of the tubular body.