Straight seam welded steel pipe standard treatment

Straight seam steel pipe weld heat treatment is a new skill to eliminate residual stress. The data preheated before welding to the heat treatment temperature after the welding process and welding pieces of the heating was continued to adhere to this temperature, after completion of welding heat applied to its cotton insulation slow cooling. This approach could usefully down welding residual stress, progressive metal's resistance to stress corrosion.

Useful heat treatment after welding the welding residual stress decrease, and the heat treatment temperature is higher, the better the effect of residual stress relief. Large diameter steel pipe weld heat treatment can also be useful for the progress of large-diameter pipe resistance to stress corrosion ability, after the heat treatment temperature is higher, resistance to stress corrosion can progress more obvious. Dispersion of metal carbide coating the workpiece is placed special skill medium, dispersed appearance of acting on the workpiece to form a layer of several tens of microns microns metal carbide layer. Large diameter steel pipe anti-corrosion of buried pipes and tubes inside out corrosion, are made of galvanized wire hanging, spraying compressive strength of not less than 30 N/mm2 cement mortar fabric.

Because the internal weld destructive testing of the pipeline project in the water supply pipe attributed to large, especially the thickness t = 30 mm steel tube is utilized as a pipe bridge, we must accept the internal water pressure, but also bear the weight of steel pipes and water bodies constituted moment, so the welding quality requirements are particularly high. About the pipe bridge of t = 30 mm thick with a large-diameter steel pipe, the longitudinal seam and girth welds were attributed to a class, the demand for 100% of the X-ray film viewing and 100% of the ultrasonic flaw view; while the thickness t = 24 mm buried steel pipe, welded longitudinal seam attributed to a class for 20% of the X-ray film viewing and 50% of the ultrasonic flaw viewing.