1. manufacturing method (1) using hot rolled strip as billet, high temperature spiral forming is often adopted, automatic submerged arc welding is used for spiral seam, and internal and external submerged arc welding seam is not less than 1. (2) the allowable weld head on the steel pipe should not be less than 300mm from the pipe end. The buyer agrees with the manufacturer to allow the head to be welded to the tube end, but the circumference between the head and the corresponding tube end spiral candle should be at least 150mm. (3) the length of each short steel pipe shall not be less than 2m for each section of the pipe which allows two short sections of the same size and the same model. The two sides of the annular weld should be interlaced and the distance of the ring is less than 150mm.

High precision cold drawn steel pipe is a new type of high-tech energy-saving product. In recent years, the technology used in the production of precision steel pipes has been widely used in the domestic hydraulic, pressure cylinder, coal mine support (pillar), oil pump pipe, Jack and other manufacturing fields. The high precision cold drawn precision steel pipe is important to popularize the use of saving steel, improving machining efficiency, saving energy, and reducing investment in hydraulic cylinder and cylinder processing equipment.

The inner and outer wall of the cold drawn precision steel pipe has no oxidation layer. It bears high pressure and no leakage, high precision, high finish, cold bending, no deformation, smooth flared mouth without cracks, and rust prevention treatment on the surface. It is mainly used for mechanical structure, hydraulic equipment and pneumatic or hydraulic components for automobile and motorcycle, such as cylinders or cylinders.

Thin-walled seamless pipe fittings are increasingly used in the industrial sector because of their compact structure, light weight, and material-saving features. However, thin-walled thin-walled tubes have low strength, poor rigidity, and are easily deformed during processing, making it difficult to ensure the accuracy of parts processing. Thin-walled parts processing has become a prominent problem. There are many factors that affect the machining accuracy of thin-walled seamless pipe parts. Machine tool, cutting tool, workpiece and workpiece clamping, cutting force during cutting process, cutting heat, etc. all cause parts machining errors. Thin-walled seamless pipe parts are more difficult to machine, especially for hole machining. Due to the effect of cutting forces on the part during the cutting process, it is prone to deformation. Cause oval or medium and small, two "waist" phenomenon. In addition, thin-walled parts due to poor heat dissipation in the process, easy to produce thermal deformation, size and shape errors can not meet the requirements of the drawings, so that parts of the shape and error increases, it is not easy to ensure the quality of parts processing. How to reduce the impact of cutting force on the deformation of the workpiece, so as to fully consider the impact of process problems on the quality of the part processing, preparation test of the workpiece clamping, tool geometry, cutting amount and other processes, effectively overrun. During the deformation process of thin-walled parts, the machining accuracy is guaranteed. The characteristics of thin-walled parts: According to the technical requirements of the drawings, the workpiece material is processed using seamless steel tubes. The surface roughness Ra1.6 of the hole and outer wall can realize turning processing. However, the requirements for the hole diameter of 0.03 for thin-walled seamless pipe fittings are relatively high. In mass production, the process route is roughly: cutting heat treatment - vehicle end car hole - quality inspection.

According to foreign media reports, the India iron and steel minister, Aruna Sharma (Aruna Sharma), in a recent event, said the India government will try to relax the market access of large foreign enterprises to encourage them to invest in new steel projects in India. By 2020, India's steel output is expected to increase from 1.34 billion tons to 1.5 billion tons. "Previously, there were some problems in the process of new steel projects in India, but now India has great room for developing large-scale steel projects. If anyone wants to build large steel projects in India, we will lay a red carpet for them and welcome them. Aruna Sharma said. It is understood that at present, India has not yet received applications for new steel projects by foreign enterprises, and most foreign investors are still on the sidelines. In addition, Aruna Sharma also urged the India steel industry to use new technologies to reduce the use of coking coal in steel production, because the coal reserves in India and most of the Asian countries are not much.

(A) Seamless steel pipe size accuracy In order to determine the position of the shaft, it is usually required for its dimensional accuracy (IT5 ~ IT7). The accuracy of the journal size of the assembly drive is generally low (IT6 ~ IT9).

P91 steel is filled with pearlite heat-resisting steel and austenitic heat-resisting steel, martensitic heat-resisting steel in the temperature range of new soda pipe line steel 600~650°C. The maximum temperature is 650°C in the original 9Cr-1Mo. Actual production based on steel. Added strengthening elements such as V, Nb, and N to form a new type of steel deterioration.

P92 high-pressure boiler tube is based on P91 steel, using a variety of enhanced new ferritic heat-resistant alloy steel pipe, good high temperature strength and creep properties of the research and development approach. Compared to P91, which is used at the highest temperature, P91 is used as a replacement for heads and steam pipes in the high temperature and pressure parts of large metal-fired boilers. Due to the tungsten, molybdenum compound solution, and reinforced multi-reinforcement devices, the P92 performance test P91 difficult-to-grind device is quite large, and the temperature selection scroll range is narrow. The team members of the technology center, based on summing up past experience, put high alloy tube system technology into full consideration of the equipment's production capacity and production process conditions, and actively explored the two-tube Assel rolling mill to improve the heating system, optimize the process parameters, and tools. The distribution of shape and deformation, in strict accordance with the internal control standards of production units, successfully rolled Φ168×30mmp92 high-pressure boiler tubes.

High-precision cold-drawn steel pipe is a new type of high-tech energy-saving product. In recent years, the use of precision steel pipes produced by this technology has been widely used in domestic manufacturing fields such as hydraulic and pneumatic cylinders, coal mine underground supports (pillars), oil pump pipes, and jacks. High-precision cold-drawn precision steel tubes promote the use of economizing steel, improve processing efficiency, save energy, and reduce investment in hydraulic cylinders and block processing equipment is very important.

A106B seamless steel pipe thread inspection is more complex and divided into the screw thread test and pipe thread test. 1. Collar thread inspection After the processing of the wire, the internal taper, the inner pitch, the thread height and the concentricity are tested, and the tightness and the comprehensive parameters are checked by the thread plug and the incomplete head. In addition, the thread surface according to API standards for artificial eye inspection.

Resistance-welded tubes (abbreviated as welded tubes) can only occur under certain circumstances and have the following characteristics: (1) Stress corrosion cracking occurs only when stress (especially tensile stress) is present. This stress can be applied stress, or residual stress introduced during welding and joining, or expansion stress caused by wedge action of the corrosion product. (2) Stress corrosion cracking is a time-dependent lag damage that is completely similar to hydrogen hysteresis cracking. (3) Stress corrosion cracking is a kind of low stress brittle fracture.

SA 213 Standard Specification for Seamless Ferritic and austenitic alloy steel boilers, superheater and heat exchanger tubes. 1. surface state: The austenitic stainless steel pipes should be cleaned and descaled. When using bright annealing, no pickling is necessary.

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Seamless steel pipe can be divided into two kinds of seamless pipe and seamless square pipe. Seamless pipe is the most important use in pipeline and machinery industry, such as oil pipeline and natural gas pipeline, natural gas pipeline, etc. . Seamless pipe is mainly used in the construction industry. Seamless steel pipe needs antirust paint before pipe, and seamless square pipe is galvanized first, galvanizing is mainly divided into two ways of galvanizing and hot-dip galvanizing. We usually see that the galvanized seamless square pipe is usually hot-dip because hot-dip galvanized seamless steel pipe is much stronger than galvanized seamless steel pipe, because the main use of seamless steel pipe is built. Steel structure, color steel room and so on will inevitably be weathered and eroded. It may rust and rot for a long time. So it is necessary to have a whole outside the protective film, but the paint looks too ugly, and can not help revealing, so someone came up with a galvanizing method. Sure, galvanized seamless square tube is very popular. The seamless square tube is also used as the main frame of motorcycle, the main frame of electric vehicle and so on. It also serves as a conduit to send wires and so on. In recent years, the development of the oil pipeline industry and the steel structure construction industry has been developing very rapidly in our country. At the same time, the development of seamless steel pipe has been promoted. Accordingly, we will become the largest seamless steel pipe producing country in the world.

1, chemical composition In order to improve the uniformity of chemical composition and purity of steel, reduce non-metallic inclusions in the pipe and improve its distribution, steel refining is often used by furnace steelmaking equipment, and even the electric slag furnace is used for remelting refining tubes.

The main production processes of high pressure pipe are: tube billet heating, tube billet perforation and steel pipe extension.

Differences in manufacturing process: Galvanized steel pipe and seamless steel pipe are two kinds of steel tubes. The surface of galvanized steel tube is galvanized. It may be welded pipe, it may also be seamless tube. Seamless steel pipe is the corrosion resistance of seamless galvanized pipe in the manufacturing process, and seamless steel pipe can bear high pressure. Galvanized steel pipe is not easy to rust, galvanized steel pipe is not easy to rust, galvanized steel pipe is more than seamless steel pipe. If it is used for balcony, it is best to use galvanized light tube, not suitable for using seamless steel tube balcony, because the wall thickness of seamless steel pipe is heavy, and the cost of seamless steel pipe is higher than that of galvanized steel pipe, and the galvanized steel pipe is very durable. Longer life than seamless steel pipe. If the quality is good, the use of more than 20 years should not be a problem, of course, welding and painting should be done, and will not affect the service life of galvanized steel tube.

ERW steel pipe is made of hot-rolled steel plate as raw material, its wall thickness can be controlled uniformly at ±0.2mm, and the two ends of steel pipe are according to American APl standard or GB/T9711.1 standard, repaired end beveling, fixed length delivery, etc. advantage. In recent years, various natural gas pipeline network projects and gas companies have widely adopted ERW steel pipes as the main steel pipes of urban pipe networks.

On April 23rd, Shanghai Baoye won the bid for the 3,500-ton iron and steel conglomerate No. 2 high line and No. 3 bar construction general contracting project of the Malaysian Zhongguandan Industrial Park in Malaysia. The project is located in Kuantan Industrial Park, Malaysia. The contract period is 150 days. The 2# high-line project will build an annual output of 650,000 tons of 5.5 to 16.0 millimeter round steel wire rods. The steel grades will be rolled carbon steel, high-quality steel and low-alloy steel rolling projects and supporting facilities; the newly-built No. 3 bar shop will be designed to produce 13 10,000 tons, the main products are hot rolled smooth round steel and rebar. The successful bid of this project was based on the results of Malaysian Mazhong Kuantan Industrial Park Steelmaking, Vietnam River Jing Steelmaking, Cambodian Conch Cement and other projects, combined with the national “One Belt and One Road” initiative, gaining a firm foothold and expanding market results, further enriching The overseas market performance of the company has created the brand of “National Team of Metallurgical Construction” for the company. It has unswervingly exerted the advantages of technology, management and brand in the metallurgical field, and has further laid a foundation for further strengthening, further development, and entrepreneurship, and has continued to consolidate the leading position of the metallurgical market. .

According to foreign media reports, Indian Ministry of Industry and Commerce officials stated that India is “seriously considering” the WTO's complaint against the US steel and aluminum tariffs unless India receives Trump's metal tariff exemption.

(1) groove pickling. After installation, the installed pipeline is decomposed into acid bath bath after two installation. This method is suitable for a few occasions such as short pipe diameter, large diameter, easy disassembly, small pipeline system and hydraulic pipeline construction, such as pump station and valve station, can be washed by trough acid.