Cold Drawn Seamless Mechanical Tube

According to different production methods, it can be divided into hot rolled tube, cold rolled tube, cold drawn tube, extrusion tube and so on. Cold drawn seamless steel tube with hot rolled seamless steel tube is the biggest difference between cold drawn seamless steel tube precision is better than hot rolled seamless steel tube, cold drawn seamless steel tube of the general accuracy about 20 silk, and the precision of the hot-rolled seamless pipe in about 100 silk, so cold drawn seamless steel tube is a mechanical processing manufacturing industry, the first selection of parts and components manufacturing.

1.1. Cold Drawn Seamless Mechanical Tube, Generally, it is produced on automatic pipe rolling set. The solid tube blank is checked and cleared of surface defects, cut into the required length, centering on the perforated end face of the tube blank, and then sent to the heating furnace for heating, and perforated on the punch machine. In the perforation at the same time continuous rotation and forward, under the action of the roll and the top, the tube blank gradually formed a cavity, called the wool tube. Then it is sent to the automatic pipe mill to continue rolling. Finally, the wall thickness of the whole machine is even, and the sizing (reducing) machine is sizing (reducing) to meet the specification requirements. It is an advanced method to produce hot rolled seamless steel tube with continuous rolling tube set.

1.2. Extrusion method: The heated tube blank is placed in a closed extrusion cylinder, and the perforated rod moves together with the extrusion rod to extrude the extruded parts from the smaller die hole. This method can produce smaller diameter steel pipe.

Use

2.1, seamless pipe is widely used. General purpose seamless pipe by ordinary carbon structural steel, low alloy structural steel or alloy structural steel rolling, production is the most, mainly used for conveying fluid pipes or structural parts.

2.2. Supply in three categories according to different uses: a. Supply in accordance with chemical composition and mechanical properties; B. Supply according to mechanical properties; C. Supply according to water pressure test. Steel tubes supplied under class A and CLASS B, if used to withstand liquid pressure, are also subjected to hydrostatic test.

2.3, special use of seamless tube boiler seamless tube, geological seamless tube and oil seamless tube, etc.

Cold Drawn Seamless Mechanical Tube, species

3.1 Seamless steel tube can be divided into hot rolled tube, cold rolled tube, cold drawn tube and extruded tube according to different production methods.

3.2 according to the shape classification, there are circular pipes and special-shaped pipes. Special-shaped tube except square tube and rectangular tube, there are elliptical tube, semicircle tube, triangle tube, hexagonal tube, convex tube, plum tube and so on.

3.3, according to the different materials, it is divided into ordinary carbon structure tube, low alloy structure tube, high quality carbon structure tube, alloy structure tube, stainless tube and so on.

3.4. According to special purposes, there are boiler pipes, geological pipes, oil pipes, etc.

Specifications and appearance quality

Seamless pipe according to GB/T8162-2018 regulations

4.1 Specification: Hot-rolled pipe diameter 32 ~ 630mm. The wall thickness is 2.5 ~ 75mm. Cold rolled (cold drawn) tube diameter 5 ~ 200mm. The wall thickness is 2.5 ~ 12mm.

4.2 Appearance quality: The internal and external surface of the steel pipe shall not have cracks, folding, rolling, lamination, hair lines and scar defects. These defects shall be completely removed without allowing wall thickness and od to exceed negative deviations.

4.3 Both ends of the steel pipe should be cut at right angles and burrs removed. Steel pipes with wall thickness greater than 20mm allow gas cutting and hot saw cutting. By the agreement of both sides of supply and demand also can not cut the head.

4.4 Cold-drawn or cold-rolled precision seamless steel pipe Surface Quality refer to GB3639-2018.

Component test

5. Chemical composition test

5.1 The chemical composition of domestic seamless tubes supplied according to chemical composition and mechanical properties, such as Steel No. 10, 15, 20, 25, 30, 35, 40, 45 and 50, shall conform to the requirements of GB/T699-88. Imported seamless pipes shall be inspected according to relevant standards stipulated in the contract. The chemical composition of 09MnV, 16Mn, 15MnV steel should comply with the provisions of GB1591-79.

5.2 Refer to gb223-84 "Methods for Chemical Analysis of Steel and Alloy" for specific analysis methods.

5.3. Refer to GB222-84 "Allowable Deviation of chemical Composition of steel samples and Finished products for chemical Analysis".

Physical properties of

6.1 For domestic seamless pipes supplied according to mechanism performance, ordinary carbon steel shall be made according to GB/T700-88 Class A steel (but the sulfur content shall not exceed 0.050% and phosphorus content shall not exceed 0.045%), and its mechanical properties shall conform to the values specified in the TABLE GB8162-2008.

6.2 The domestic seamless pipes supplied according to the hydrostatic test must meet the hydrostatic test stipulated in the standard.

6.3 Physical performance inspection of imported seamless tubes shall be carried out according to relevant standards stipulated in the contract.