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How to avoid cracking of stainless steel seamless steel pipe?

How to avoid cracking of stainless steel seamless steel pipe?

Time:2022-03-17 Source:China Wuxi JiaNuo Special Steel Co.

Domestic high-precision seamless steel pipe is generally through the increase of alloy in the metal to improve the performance of the material, seamless steel pipe after cold-drawing, are required to stress relief annealing, eliminate the residual stress of the material, improve the organization of the material, improve the plasticity of the material, so as to achieve the purpose of preventing the occurrence of fracture failure of seamless steel pipe.

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At present, the material of stainless steel seamless steel pipe in China are ordinary 45# or 20# steel 27SiMn steel, through cold-drawn deformation to improve the strength of the metal; however, it is at the expense of the plasticity and toughness of the metal. High precision cold drawn seamless steel pipe is based on its high dimensional accuracy and high strength performance in the market, it must ensure that the deformation is within a certain range to maximize the performance of the material and reduce the adverse effects on the material.

Seamless steel tube deformation is too small, can not achieve the requirements of surface finish and dimensional accuracy, but also can not reach the strength index of the components; deformation is too large, seamless steel tube plasticity, toughness reduced too much, and, the grain is pulled excessively thin, the formation of fibrous tissue, the metal will have obvious anisotropy. The axial direction of cold-drawn seamless steel pipe, parallel to the elongation direction of the grain, the strength increases; the radial direction of cold-drawn seamless steel pipe, perpendicular to the elongation direction of the grain, the strength decreases, and the maximum stress of the hydraulic cylinder is present in the radial direction of the seamless steel pipe, so the deformation is too large to give full play to the performance of the cold-drawn tube.