Selection principles of non -destructive detection methods on the surface of straight seam steel pipes: Magnetic powder detection is selected, and non -iron magnetic steel pipes are selected for penetration test.
For welding joints with a thermal crack tendency, an important surface non -destructive detection should be performed after welding and thermal treatment. For welding joints with delayed cracks, research and detection should be performed after a period of working time for a period of cooling for a period of time.
Surface non -destructive detection application is implemented according to standard requirements. Objects and applications of non -destructive detection on the surface are generally as follows:
(1) Quality inspection of the outer surface of the pipe.
(2) Emphasized welded welding seams on the detection of surface defects.
(3) The detection of defects on the surface of important corner welds.
(4) Detection of important inheritance welding and cross -linked tri -teasing branch tube welding joint defects.
(5) Poor test of high -hardening tendency welding joint.
(6) Check the grooves of non -athlete stainless steel pipes with less than 29 degrees Celsius below 29 degrees Celsius.
(7) Test the test of double -sided welding seams after washing.
