Seamless steel pipe production process

Seamless pipes have a hollow cross-section and are widely used as pipes for transporting fluids, such as pipes for transporting oil, natural gas, gas, water, and certain solid materials. Compared with welded steel pipes, steel pipes are lighter in weight when they have the same flexural and torsional strength, and are economical section steels. Widely used in the manufacture of structural parts and mechanical parts, such as oil drill pipes, automobile drive shafts, bicycle frames, and steel scaffolds used in construction, etc., use steel pipes to make ring parts

The production process of seamless steel pipe mainly includes:

1. Hot rolled. The hot rolling process is made by heating the steel billet to above 1000°C and undergoing rough rolling, finishing rolling and other processes. It is mainly suitable for the production of carbon steel and low alloy steel pipes, and can produce large diameter steel pipes. Generally, there is a minimum order quantity requirement, and the minimum order quantity of hot-rolled seamless steel pipe is relatively high. When the demand is low, production can be combined according to the production progress of different specifications in steel mills. For large-diameter hot-rolled seamless pipes, small orders of tens of tons mostly follow the production plan of the steel mill, and the production plan will not be arranged separately. The production speed of this product is fast. However, the production cycle of small batch orders is generally more than 20 days (the specific time needs to be arranged according to the production schedule).

2. Cold drawn. Cold drawing is a processing method to reduce the diameter of seamless steel pipes, and is mainly used to produce small diameter steel pipes. The production quantity of cold drawn seamless tubing is flexible, the minimum order quantity is low, and both large and small orders can be produced. The outer diameter error of empty drawing is small and the surface is smooth, which is suitable for products with higher requirements on the outer diameter, but the inner diameter error is large. If there is a high error requirement for both inner and outer diameters, you can choose sandwich (inner diameter sandwich rod) for cold drawing. The production speed is fast, and the production cycle is generally about 7-10 days (the specific time needs to be arranged according to the production plan schedule).

3. Cold rolling. Cold rolling is carried out at room temperature and rolled by a cold rolling mill to produce small-diameter seamless steel pipes. The surface of the inner and outer diameter of the steel pipe is bright, and the error is small. Both large and small batches are suitable for customization, and the processing speed is slow. The production cycle is generally about 10-15 days (the specific time needs to be arranged according to the production plan schedule).

4. Machining. Machining is the machining of seamless steel pipes such as drilling and threading to make them into the desired shape and size.

5. Inspection. The produced seamless steel pipes are inspected in terms of size, appearance and performance to ensure product quality.

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