Seamless pipe extrusion production method

The conventional process of precision seamless pipe is furnace+ESR->forging or forging. Product shape round bar, square flat bar and forgings. The steam turbine factory conducts deep processing, but the shape of the processing technology is relatively special, and the metal utilization rate after processing is about 30%. After being produced by extrusion, it will have the following advantages:

1. The precision seamless steel pipe is in the best stress state during the hot extrusion process, reducing internal defects of the product.
2. It is easy to realize a variety of cross-sectional shapes, suitable for multi-variety and small-batch production.
3. Uniform performance in all directions.

The main production method of extrusion process: electric furnace + electroslag furnace -> forging or rolling blank -> induction heating -> extrusion -> annealing.

The difference between extrusion and forging is:
1. The heating temperature of precision seamless extrusion is 30-60℃ higher than that of forging and rolling production;
2. Deformation and fast speed (deformed steel only needs 2-4S).
3. There are many processes and the metal consumption is large.

broken seamless pipe

After cold drawing metal alloys and seamless carbon steel pipes, stress relief annealing is required to eliminate the residual stress of the material, improve the structure of the material, improve the plasticity of the material, and prevent the material from failing. The purpose of seamless steel pipe fracture failure.

At present, the stainless steel seamless pipe adopts ordinary 45# or 20#27SiMn steel, which increases the strength of cold-drawn metal; however, its price is the metal cost of plastic and toughness. On the basis of high dimensional accuracy and high strength performance, the precision cold-drawn seamless steel pipe needs to ensure a certain deformation range in order to maximize the performance of the material and reduce the negative impact of the material.

The deformation of the seamless steel pipe is too small to meet the requirements of surface finish and dimensional accuracy, and cannot meet the strength index of the component; Significant anisotropy appears. The axial elongation of the cold-drawn seamless steel pipe increases parallel to the grain strength direction, while the radial-drawn seamless steel pipe is perpendicular to the grain in the elongation direction, but the strength is lower. The maximum pressure of the seamless steel pipe is radial, and the deformation is too large, which can give full play to the unfavorable performance of the cold drawn steel pipe.

Article source: https://article-realm.com/article/Finance/39083-Seamless-pipe-extrusion-production-method.html