Quality inspection method of seamless steel pipe:
(1) Geometric specification detection of seamless steel pipes
The diameter, thickness, bending degree, and length of the seamless steel pipe can be inspected on the inspection table with external calipers, vernier calipers, bending level rulers, and length meters.
For external opening diameter, thickness and length, automatic specification inspection equipment (such as automatic diameter measuring, thickness measuring and length measuring equipment) can also be used for continuous inspection. For the OCTG seamless steel pipe, the main parameters of the external thread must also be checked.
(2) Inspection of inner and outer layers of seamless steel pipes
Generally, the inner and outer layers are inspected by estimation, and in addition to the estimation, the inner surface can also be inspected with a reflective prism. Some unique and main purpose seamless steel pipes are also required to be inspected for the internal and external process performance of seamless steel pipes according to non-destructive testing, including eddy, magnetic flux leakage, ultrasonic, and magnetic particle inspection.
(3) Physical performance and performance testing
In order to certify the physical properties of the seamless steel pipe considering the provisions of the specification, the seamless steel pipe must be sampled for physical property testing.
The key physical properties testing includes compressive strength, tensile strength, elongation, impact power, etc. The key to use performance testing includes squeezing test, flaring test, pressing test, rolling test, cold drawing test, perforation test, etc. This new testing project has certain selections based on the differences in specifications and the main uses of seamless steel pipes.
(4) Non-destructive testing
Non-destructive testing refers to the immediate inspection of the internal and surface defects of the seamless steel pipe without destroying it. At this stage, magnetic flux leakage testing, ultrasonic flaw detectors, vortex and fluorescent magnetic particle testing, etc. have long been widely used in seamless steel pipe companies. In recent years, the non-destructive testing method has a great development trend. Recently, new technologies such as acoustic emission holography, ultrasonic spectrum analysis flaw detection, ultrasonic imaging flaw detection and ultrasonic high temperature flaw detection have appeared.