1. What materials of steel pipes does GB/T 8162 apply to?
GB/T 8162 "Seamless Steel Pipes for Structures" applies to seamless steel pipes for mechanical structures and general engineering structures. Common materials include 20#, 35#, 45# and other carbon steels, as well as some alloy steels such as 20Cr, 30Cr, etc. Shandong Suyang Special Steel Co., Ltd. operates seamless pipes that meet GB/T 8162 standards, including 20G, 15CRMOG, 12CR1MOVG, etc.
2. What material grades have been deleted and added in GB/T 8162?
Compared with GB/T 8162-2008, the 2018 version of the standard deleted the grades and related technical requirements of Q235, Q275, Q295, 12CrMo, 15CrMo, 12CrMoV, 12Cr1MoV; added the grades and chemical composition and carbon equivalent table of low-alloy high-strength structural steel, as well as the grades and related technical requirements of Q500, Q550, Q620, Q690 low-alloy high-strength structural steel.
3. What is the difference in material selection between GB/T 8162 steel pipe and GB/T 8163 steel pipe?
GB/T 8162 standard is applicable to seamless steel pipes for general structures and mechanical structures, and GB/T 8163 standard is applicable to general seamless steel pipes for conveying fluids. GB/T 8163 steel pipes need to be hydraulically tested or ultrasonic, eddy current, and magnetic flux leakage tested one by one, so GB/T 8162 is not suitable for the standard selection of pressure pipeline steel pipes.
4. What aspects are included in the mechanical property testing of GB/T 8162 steel pipes?
The mechanical property testing of GB/T 8162-2018 seamless steel pipes for structures mainly includes tensile testing and cold bending testing. The tensile test tests the yield strength, tensile strength, and elongation of the steel pipe; the cold bending test evaluates the cracks and cracking of the steel pipe after bending to ensure its toughness. For example, the tensile strength of Xiangyang GB/T 8162-2018 seamless steel pipe is 370MPa~480MPa, the yield strength is 280MPa, and the elongation δ5(%) is 26%.
5. How to ensure that the chemical composition of GB/T 8162 steel pipes meets the standard?
To ensure that the chemical composition of GB/T 8162 steel pipes meets the standard, it is necessary to conduct chemical composition analysis on the steel pipe materials. Through professional analysis methods, the content of various elements in the steel pipe is tested to ensure that it is consistent with the low-alloy high-strength structural steel grade specified in the standard. During the testing process, the chemical composition requirements specified in the GB/T 8162-2018 standard must be strictly followed.
