• API 5CT N80 casing and tubing pipe
• API 5CT K55 casing and tubing pipe
• API 5CT J55 casing and tubing pipe
• EN10028-2 16Mo3 Boiler and Pressure Vessel steel Plate Notch impact energy
• EN10028-2 P265GH Pressure vessels steel equivalents
• EN 10210 S355J2H low alloy carbon structural steel
• EN 10210 S355J0H steel hollow materials
• GB/T 18248 34CrMo4
• GB/T 18248 35CrMo alloy steel
• 30CrMo steel Heat treatment, 30CrMo steel tube/pipe

K55 is higher than J55 steel

API-5CT K55 oilfield casing pipe is very similar to J55, there is no significant difference in the chemical composition and yield strength, however the ultimate tensile strength of K55 is higher than J55 steel, K55/J55 are 655MPa and 517MPa respectively.

Heat treatment
PSL1 requirements: J55 and K55 same way (can be rolled-state delivery);
PSL2 requirements: J55, K55 product should be normalized or normalized and tempered overall, if thick, should be normalized or normalized and tempered after thickened.
Impact test
J55 and K55 impact test must be done, the minimum size of the sample lateral impact energy 20J, the smallest full-size sample longitudinal impact energy 27J.
Wall thickness detection
PSL1: J55 and K55 for measuring the wall thickness of no coverage requirements;
PSL2: J55 and K55 for wall thickness measurement and recording deal with the entire length of the best coverage of the surface area of ​​automatic detection system should reach 25%.
NDT
PSL1: J55 and K55 on the tube did not do destructive testing mandatory requirements;
PSL2: J55 and K55 for all pipe shall be one or more of the criteria specified in 10.15.5 tested to find the inner surface of the outer surface of the pipe and can receive the level of L4 longitudinal imperfections.