In addition to the additional stress in the axial direction, there are additional stress in the tangential direction in the process of empty drawing. Longitudinal crack is caused by additional tangential tension stress produced during pull-out.
Hebei shengtian pipe-fitting group Co., ltd is usually used if there is no special requirement. Seamless steel pipe is made of No. 20 steel, which is not hardened and has no tempering brittleness. The cold deformation has high plasticity and is generally used for bending, calendering, bending and hammer arch processing. The welding performance of arc welding and contact welding is very good, and the thickness of gas welding is relatively small. Generally, it is used for manufacturing under conditions of low pressure resistance but high toughness requirement.
Seamless steel pipe is made of ingot or solid billet through perforation, and then hot-rolled, cold-rolled or cold-drawn. Seamless steel pipe plays an important role in China's steel pipe industry. It is also one of the advantages of the seamless steel pipe that its manufacturing process is rigorous and it is not allowed to make a millimeter difference outside the specified scope.