JIS G3444 STK540 LSAW Steel Pipe DN1400

STK540 is a high-strength structural steel specified in JIS G3444, commonly used for demanding load-bearing applications. The material typically provides a minimum yield strength of approximately 390 MPa and tensile strength ranging from about 540 to 720 MPa. Its controlled chemical composition, generally maintaining carbon below about 0.25 percent with balanced manganese content, ensures both strength and good weldability. These characteristics make STK540 particularly suitable for large structural members and heavy engineering projects.

At Huayang Steel Pipe, DN1400 LSAW pipes are produced using high-quality wide steel plates through the JCOE forming process, which ensures consistent roundness and stable wall thickness distribution. The longitudinal weld seam is completed using double submerged arc welding to achieve deep penetration and strong metallurgical bonding. Comprehensive inspections including ultrasonic testing of the base metal, weld seam non-destructive testing, and hydrostatic pressure testing are carried out to guarantee structural reliability when the pipes are used in large-scale infrastructure and structural engineering applications.