国内外螺旋焊接钢管制管概况
A Survey of Spiral-welded Steel Pipe Fabrication at Home and Abroad
-
摘要: 分析了国内外螺旋焊接钢管的制造情况, 通过对母材的物理、化学性能对比指出, 国外生产的X65、X70低合金钢, 在强度、韧性、可焊性等方面, 比国产的A3、16Mn钢更适合当今输油管道的制管要求。在钢材冶炼过程中, 加入多种微量元素是提高钢材材质的重要措施, 高强度、低合金钢是解决轧制过程中板卷问题的关键。制管机组成型器的大桥和转盘由固接改为铰接后, 在调整焊缝间隙时, 不再会影响管径的尺寸了。由内成型器替代外成型器, 减少了成型管子的残余应力, 使管子的后变形小, 保证了管子的几何尺寸, 提高了制管质量。在国内, 加强老机组的改造和成型理论的研究是制管行业的迫切任务。Abstract: This paper analyses the spiral-welded steel pipe fabrication both at home and abroad. By comparing the physical and chemical performances of base materials, it is pointed out that, in terms of strength, ductility and weldability, the X65 and X70 low alloy steel pipes made abroad are more applicable for the current requirements of oil transportation than the A3 and 16Mn steel pipes made in China. Alloying of multiple microelements in the cause of rolling process is a major measure to improve steel quality. High strength and low alloy steel shall be adopted to prevent plate from bending during rolling process. Pipe size will no longer be affected during weld clearance adjustment by changing the fixed joint to hinge joint between overbridge and rotary table of the pipe forming mechanism in pipe fabricating machine. The replacement of outside former with inside one can reduce the residual stress in the formed pipe, resulting in smaller after-deformation, therefor, the pipe geometric size is guaranteed-and the quality of pipe fabricated improved. The urgent task for the domestic industry of pipe fabrication is to speed up the upgrading of the old machines and the theoretical studies on pipe formation.