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Carbon steel seamless steel tube factory inspection process
Jan 24, 2019

Carbon steel seamless steel tube factory inspection process


The inspection of steel tube generally includes: the inspection of geometric size, surface quality;Inspection of chemical composition, mechanical properties, technological properties and high-low microstructure;Nondestructive inspection;Some special performance inspection and measuring length weighing etc.


(1) check the geometric dimensions of steel pipes

The outside diameter, wall thickness, bending degree and length of the steel tube can be checked on the inspection table with external callipers, micrometers, bending degree and length tape.


For outer diameter, wall thickness and length, automatic size measuring devices (such as automatic diameter, thickness and length measuring devices) can also be used for continuous testing.In the late 1980s, the steel pipe factories put into production generally have online automatic diameter and thickness measuring devices, and have length measuring and weighing equipment in the finishing area.For OCTG steel pipe also need to check the thread parameters.


(2) inspection of the inner and outer surfaces of steel pipes


In general, visual inspection is used for internal and external surface inspection, and in addition to visual inspection, the internal surface can also be used for reflection prism inspection.Some special purpose steel tubes are required to pass nondestructive inspection, including eddy current, magnetic flux leakage, ultrasonic, magnetic powder inspection, etc.


(3) check mechanical properties and technological properties


In order to verify that the mechanical properties of steel pipes meet the standard requirements, it is necessary to test the mechanical properties of steel pipes by sampling.


Mechanical property test mainly includes tensile strength, yield strength, elongation, impact work, etc.Process performance test mainly includes flattening test, flaring test, water pressure test, edge rolling test, cold bending test, perforation test, etc.These inspection items are selected according to the different standards and the different USES of steel tubes.


(4) nondestructive inspection


Nondestructive inspection refers to the inspection of internal and surface defects of steel tubes without damaging them.At present, magnetic flux leakage testing, ultrasonic testing, eddy current testing and fluorescent magnetic particle testing have been widely used in steel tube enterprises.In recent years, there have been great developments in nondestructive testing, and recently there have been new techniques such as acoustic emission holography, ultrasonic spectrum analysis testing, ultrasonic imaging testing and ultrasonic high temperature testing.