With the accelerated expansion of global offshore oil and gas exploration and development into deep-sea and ultra-deep-sea areas, and the booming development of emerging industries such as offshore wind power and deep-sea mining, marine engineering structures are placing higher demands on the reliability, corrosion resistance, and ability to withstand extreme working conditions of core pipe materials. LSAW (Straight Seam Submerged Arc Welded Pipe), with its outstanding advantages such as large diameter, thick wall, and stable mechanical properties, has become the preferred pipe material for core structures such as offshore platform foundations, subsea oil and gas pipelines, and risers, providing solid technical support for the implementation of my country's maritime power strategy.
Marine engineering projects long face extreme working conditions such as high salt spray, high pressure, strong ocean currents, and microbial corrosion. As the "lifeline" of offshore oil and gas fields, the quality of subsea pipelines directly affects the safety and efficiency of marine resource development. Previously, some marine engineering projects experienced corrosion leaks and structural deformation due to insufficient pipe material compatibility, highlighting the importance of scientific material selection for core pipe materials. In recent years, with continuous breakthroughs in materials technology and manufacturing processes, the performance of LSAW (straight seam submerged arc welded) pipes has been continuously upgraded, gradually solving the service challenges in extreme deep-sea environments.
Industry experts point out that the widespread application of LSAW pipes in marine engineering is inseparable from three core breakthroughs. In terms of material compatibility, the industry generally adopts low-carbon micro-alloyed steel, strictly controlling the content of impurity elements. Acid-resistant steel grades such as X65MO and X70, developed specifically for the acidic environment of the deep sea, can effectively resist risks such as chloride ion corrosion and stress corrosion cracking. In terms of manufacturing processes, advanced forming processes such as UOE and JCOE, combined with double-sided submerged arc welding technology and post-weld stress-relieving heat treatment, ensure the dimensional accuracy and weld reliability of the pipes, with wall thickness deviation controllable within ±0.5mm. In terms of standards and compliance, all products strictly adhere to international standards such as API 5L PSL2 and DNV-ST-F101, as well as relevant domestic specifications, passing mandatory tests such as drop hammer tear tests, hydrostatic tests, and full-process non-destructive testing to ensure service safety.
With the completion of my country's 14th Five-Year Plan for oil and gas pipeline networks and the release of demand from emerging fields such as deep-sea mining and offshore wind power, the market demand for LSAW (submerged arc welded) pipes continues to climb. Data shows that in 2025, the market size of my country's LSAW pipe industry reached 48.236 billion yuan, with a significant increase in demand from the marine engineering sector. The market size is projected to further increase to 50.505 billion yuan in 2026. Currently, domestically produced LSAW pipes have achieved full-chain integration from technology verification and domestic demonstration to international commercial application, with products exported to more than 10 countries and regions, breaking the international monopoly on high-end products.
Industry insiders indicate that as deep-sea development extends to ultra-deep water areas of 6000 meters, LSAW pipes will be upgraded towards higher strength, better corrosion resistance, and intelligent manufacturing. Research institutions and enterprises will continue to strengthen independent innovation, tackle key material technology challenges in extreme deep-sea environments, optimize manufacturing processes and quality control systems, and promote the large-scale and high-end application of LSAW straight seam submerged arc welded pipes in the field of marine engineering, injecting new momentum into the efficient development of marine resources and the guarantee of energy security.
