1. Heat treatment (there is a difference between PSL2 and PSL1)
PSL1 requirements: J55 and K55 have the same method (delivery in rolled state);
PSL2 requirements: J55 and K55 products should be normalized or normalized and tempered as a whole, if they are thickened, they should be normalized or normalized and tempered after thickening.
2. Straightening (no difference)
3. Chemical composition (no difference in control)
4. Tensile test (the minimum tensile strength is different)
J55: Yield strength 379MPa~552MPa; tensile strength ≥517MPa;
K55: Yield strength 379MPa~552MPa; tensile strength ≥655MPa;
Due to the different tensile strengths, the minimum elongation required for J55 is 19% and K55 is 15%.
5. Impact test (there is a difference between PSL2 and PSL1)
Tube body: PSL1 J55 and K55 have no requirements;
PSL2 J55 and K55 require the minimum transverse impact energy of full-size specimens to be 20J, and the minimum longitudinal impact energy of full-size specimens to be 27J.
Coupling: J55 and K55 impact tests must be done. The minimum transverse impact energy of the size specimen is 20J, and the minimum longitudinal impact energy of the full-size specimen is 27J.
6. Water pressure test (no difference)
7. Wall thickness detection (there is a difference between PSL2 and PSL1)
PSL1: No measurement coverage requirements for J55 and K55 wall thickness;
PSL2: The wall thickness measurement and recording of J55 and K55 should be carried out for the full length, and the surface area covered by the automatic detection system should preferably reach 25%.
8. Non-destructive testing (there is a difference between PSL2 and PSL1)
PSL1: There is no mandatory requirement for non-destructive testing of J55 and K55 steel grade pipes;
PSL2: All Steel Pipes of J55 and K55 steel grades shall be inspected by one or more of the methods specified in the standard 10.15.5 to find that the outer and inner surfaces of the steel pipe can receive horizontal L4 longitudinal defects.
9. Identification (color band difference)
A bright green band is sprayed on the J55 grade steel pipe body, a bright green band is sprayed on the coupling, and a white band is added on top;
K55 steel grade pipe body is sprayed with two bright green bands, and the coupling is sprayed with bright green, without additional color bands.
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