Cracks may appear in the welding process of high-frequency welded pipe, which are manifested in long cracks, some regular cracks, irregular cracks, etc

According to the importance ofthe structure, load characteristics, weld form, working environmentand stress state, different quality grades shall be selectedaccording to following principles.

Inthe welding process, the metal to be welded undergoes heating,melting, subsequent solidification and continuous cooling due to heatinput and transmission. This is called the welding thermal process.

Basedon the skin effect, proximity effect, eddy current thermal effect andelectromagnetic induction principle of charge, high frequency welded pipe locally heats the steel at the weld edge to the molten state.The purpose of weld welding is achieved through the extrusion ofbonding between crystals. Do you know what factors affect it's quality?

The heat treatment after welding is a new technique to eliminate residual stress. Preheating the material to the post-heat treatment temperature before welding and welding of the workpiece continued to keep the heating temperature, the use of insulation after the completion of the insulation of cotton to its slow cooling. This method can effectively reduce the welding residual stress and improve the stress corrosion resistance of metal.

Hydrostatic test is necessary to ensure the quality of welded pipe production equipment. Currently, the market is on the market pipe hydrostatic testing machine working process: feeding, clamping, filled with water, pressure, pressure, pressure relief, the material.

Extrusion method refers to the metal blank into the extruder barrel, extrusion molding and extrusion rod composed of "closed" container by applying pressure to force the metal extruded rod extrusion die orifice outflow from, and access to metal plastic molding the method, which is a historic seamless manufacturing methods

Hot dip galvanized steel processing will be part of the lubricant remains in the inner and outer surfaces, after annealing in the hot dip galvanized steel surface will form a carbon film in 1980 has galvanized experts on the surface of the carb​on steel pipe a lot the study proposed carbon galvanized tube life will be adversely affected. Although since then there is no final conclusion on quantitative indicators of carbon steel pipe life impact and influence of carbon, but carbon on hot dip galvanized steel harmful but agreed to eliminate the carbon surface of the tube, it became a hot-dip degreasing zinc processing an essential part.

drilling for oil is a difficult thing in winter, the temperature is too low, ordinary steel pipe to transport trouble, so the general use of anti-corrosion pipe insulation, pipe insulation is a kind of corrosion resistance of steel, and has a good insulation performance, construction has been widely

construction machinery with a large number of rectangular pipe steel structure, which is generally used rectangular tubing.rectangular welded seam components will inevitably lead to a large section of the larger welding deformation, which must try to prevent it. the main deformation as: transverse s