Market analysis of oil pipe

　This week, the decline of oil pipe remained unchanged. It is understood that in recent years, the domestic foundry industry has been depressed, resulting in the dim demand for oil pipe, and the price has been falling. Faced with the low price of cast pig iron, the merchants are mainly wait-and-see, there is no plan to stock up for the time being. In view of the current situation, it is expected that the price of late cast pig iron will continue to decline. Beijing building materials market demand weakened, large shipment in 300-2300 tons.

　　At present, oil pipe will face the steel mill settlement price, the market rising power is insufficient, the market merchant operation is cautious, the downward range is small, the short-term market will consolidate mainly. Steel traders lack confidence in the future market. It is learned from the market that with the increase of the steel mill's shipment volume and the continuous increase of the market quantity of various specifications, the shortage of goods and the shortage of goods have been improved before. The steel traders are actively shipping in order to reduce the inventory, and they are not optimistic about the future market.

　　From the specific situation, although steel traders have actively reduced the price in order to ship, but the downstream terminal site procurement psychology is not strong, most of them are on-demand procurement, and the market transaction volume is reduced. The price of oil pipe is not stable. In order to improve the income, steel traders have to reduce the price to stimulate demand, but the effect is not ideal.

　　On the whole, the current market demand is insufficient to follow up. To sum up, oil pipe is expected that the domestic medium and heavy plate market prices will continue the weak consolidation pattern in the short term. Affected by the high level of inventory and poor shipment, the iron mills which shut down the furnace and reduced production in the early stage still have no plan to start operation in the near future. The shipment is mainly to digest the inventory in the early stage, and the future market is not very optimistic. Some iron mills said that the current transaction price is close to the bottom, and there is little profit space left. Some iron mills have increased the margin of preference.

Application of spiral steel pipe in water conservancy

　The construction of water conservancy projects requires very high data. Most water conservancy projects are built by government departments. The cost of completing a project is relatively high. There are hundreds of millions or even tens of billions of cases. The use of spiral steel pipe is only one of many guesses. The development of water conservancy project can promote the development of spiral steel pipe market, and there is a certain relationship between them.

　　Faced with a whole year of spiral steel pipe shopping mall downturn, if there is a large water conservancy project construction will certainly drive the development of spiral steel pipe shopping mall. In water conservancy construction, spiral steel pipe is essential information. The construction of dams, pools and canals in water conservancy projects requires a lot of spiral steel pipes, wire rods, round steel, etc., while the pipeline engineering in water conservancy projects needs a lot of steel pipes and various matching valves.

　　Spiral steel pipe market downturn or rely on the support of relevant departments, otherwise can not really reverse attack to change the sales situation of the pipe industry.

Elasticity of precision seamless steel pipe

Precision seamless steel pipe is a kind of steel with high elasticity. In application, especially in large-scale buildings, precision seamless steel pipe is used in most places with high elastic requirements. Why is the elasticity of precision seamless steel pipe so good? The reason is that a lot of elements are added in it.

　　The manganese steel plate which requires elasticity can be considered as "Mn series" or "SIMN series" spring steels, which belong to special alloy steels. Both 65Mn and 60Si2Mn can be used as selective materials. It can be used in the cold forming process of steel tube with large cross-section.

　　However, for the parts with small cross-section made of two materials, the cold drawing process is required to be above 500 ℃ and the tempering process is required to be above 200 ℃. And need the appropriate molding equipment and perfect process specification, ordinary heating can not achieve the effect.

What are the anticorrosion methods of anticorrosive welded steel pipe

Anticorrosive welded steel pipe is a kind of interpenetrating network polymer, which can initiate polymerization at room temperature. The two networks can learn from each other and produce a cooperative effect. It is a new type of anticorrosive coating with strong adhesion, high strength, abrasion resistance, hydrolysis resistance, corrosion resistance, water resistance and weather resistance. The requirements for rust removal on steel structure surface are not high, and the service temperature can be between - 20 and 120 Within ℃

　　What are the anticorrosion methods of anticorrosive welded steel pipe

　　1. Protective layer method of anticorrosive welded steel pipe

　　The protective layer method of anti-corrosion welded steel pipe is widely used. This kind of anti-corrosion method is to make protective layers of various materials on the surface of metal to isolate the metal products from the external corrosive medium, so as to achieve the effect of preventing corrosion. The protective layer of anticorrosive steel pipe can be formed by coating, spraying, electroplating, hot plating, spray plating, etc.

　　There are many kinds of protective coating materials for anticorrosive welded steel pipe, such as oil, paint and other coatings, and non-metallic materials such as ceramics and plastics. The electroplating and hot-dip plating of anticorrosive steel pipes generally use non corrosive metals, such as zinc, tin, chromium and nickel. Another material of anticorrosive welded steel pipe is the oxide film formed on the surface of steel, that is, black ferric oxide film, which can also play an anti-corrosion role.

　　2. Structural change method of anticorrosive welded steel pipe

　　One of the common methods of anticorrosive welded steel pipe is to change the structure of metal. There are many kinds of metals. Some heavy metals have low chemical activity and are not easy to be corroded by other substances. Some metals can effectively improve the anti-corrosion ability when used with other metals. For example, adding chromium, nickel and other materials to ordinary steel to make stainless steel can obtain better anti-corrosion effect.

Production process of pipe fitting tee

Pipe fitting tee is a kind of pipe fitting used at the branch of pipe. For the seamless pipe fittingtee, there are two kinds of Technology: hydraulic bulging and hot pressing.

　　a. Hydraulic bulging

　　The hydraulic bulging of pipe fitting tee is a forming process of expanding branch pipe by axial compensation of metal material. The process is to use a special hydraulic press to inject liquid into the tube blank with the same diameter as the pipe fitting tee, and extrude the tube blank through two horizontal side cylinders of the hydraulic press synchronously, the volume of the tube blank becomes smaller after extrusion, and the pressure of the liquid in the tube blank increases with the volume of the tube blank becoming smaller. When the pressure required for the expansion of the pipe fitting tee branch is reached, the liquid pressure in the side cylinder and the tube blank of the metal material is double Under the heavy action, the branch pipe flows along the inner cavity of the mold and expands.

　　The hydraulic bulging technology of the pipe fitting tee can be formed in one time with high production efficiency; the wall thickness of the main pipe and shoulder of the pipe fitting tee is increased.

　　b. Hot press forming

　　Hot press forming of pipe fitting tee is to flatten the tube blank larger than the tee diameter to the size of tee diameter, and open a hole at the position of drawing branch pipe; the tube blank is heated, put into the forming die, and put into the stamping die of drawing branch pipe; under the effect of pressure, the tube blank is compressed radially, in the process of radial compression, the metal flows towards the branch pipe and forms the branch pipe under the drawing of the stamping die 。 The whole process is formed by the radial compression of the tube blank and the drawing of the branch pipe. Different from the hydraulic expansion pipe fitting tee, the metal of hot pressed pipe fitting tee branch is compensated by the radial movement of tube blank, so it is also called radial compensation process.

　　Due to the use of heating and pressing tee, the tonnage of equipment required for material forming is reduced. Hot pressed tee has wide adaptability to materials, which is suitable for low-carbon steel, alloy steel and stainless steel; especially for large-diameter and thick pipe wall tee, this forming process is usually adopted.

45# seamless steel pipe characteristics

45# refers to the carbon content of this material, about 450. This kind of material in seamless steel pipe, compared with other excellent carbon steel, is also common.

　　45# steel: the average carbon content is 0.42-0.50%, the average silicon content is 0.17-0.37%, the average manganese content is 0.50-0.80%, the average sulfur content is less than 0.035%, the average phosphorus content is less than 0.035%, the average chromium content is less than 0.25%, and the average nickel content is less than 0.2545%

　　Recommended heat treatment temperature tensile strength: no less than 600MPa yield strength: no less than 355MPa elongation: 10% shrinkage: 40% impact energy: 39j steel delivery state hardness: no more than no heat treatment: 229hbs annealed steel: 197hbs application example: used to manufacture gears, racks, sprockets, shafts, keys, pins, impellers of steam turbines, compressor pump parts. %, product model 45 × product specification φ: 756mm; wall thickness: below 100mm.

Demand of ERW pipe in July

The de stocking of ERW pipe market is still continuing, but with the arrival of Meiyu season, the steel market demand is changing from the peak season to the off-season. The release of rigid demand will be limited by the rain water potential. It is difficult to recover the micro stimulation measures in the short term. In addition, the capital pressure at the end of the month aggravates the interference, and the steel rebound is weak. Although the market is good, it is still difficult to reverse the weak situation of the steel market. It is expected this week The price of erw pipe steel is weak and stable, and the stock may be increased

　　ERW pipe inventory: data show that the national steel inventory accelerated to decline last week, the largest weekly decline since this round of decline cycle. The cumulative decline of national steel inventory in recent 12 weeks has reached 29.43%, and the current inventory level has decreased by 20.64% compared with the same period last year. At present, the social inventory has been reduced to a low level, and it only takes 2-3 weeks to reach the low point in December 2013 according to the current de chemical speed. The market is excessively pessimistic, which leads to the insufficient supply capacity of social inventory of ERW pipe.

Cutting method of thick wall spiral steel pipe

　　The most common pipe cutting method of spiral steel pipe manufacturers is plasma cutting. When cutting, there will be a lot of metal vapor, ozone, nitrogen oxide smoke and dust, which will severely pollute the surrounding environment. The key to deal with the problem of dust is how to inhale all the plasma dust into the dust removal equipment, and then avoid air pollution.

　　As for plasma cutting of spiral steel pipe, the difficulties of dust removal are as follows:

　　1. When the nozzle of plasma gun is cut, the air blows out in two opposite directions together, and then the smoke and dust will come out from both ends of the spiral steel pipe. However, it is difficult to recover the smoke and dust from the suction port of the device in one direction of the spiral steel pipe.

　　2. The cold air outside the suction inlet enters the suction inlet from the outside of the machine open space, and the air volume is large, so that the total amount of smoke and cold air in the spiral steel pipe is larger than the effective air volume inhaled by the dust remover, and then it is impossible to completely absorb the cut smoke.

　　3. Because the cut part is far away from the dust suction inlet, the wind force reaching the suction inlet is difficult to pump the dust.

　　For this reason, the design principle of the dust cover is:

　　1. The air volume inhaled by the precipitator should be larger than the total amount of smoke and dust produced by plasma cutting and the air inside the pipe. A certain amount of negative pressure cavity should be formed inside the spiral steel pipe, and a lot of external air should not be allowed to enter the steel pipe as far as possible, so as to effectively absorb the smoke and dust into the precipitator.

　　2. In the future, the smoke and dust shall be blocked at the cutting point of the spiral steel pipe, and the cold air at the suction inlet shall be avoided to enter the spiral steel pipe as far as possible. A negative pressure chamber shall be formed in the internal space of the spiral steel pipe to prevent the smoke and dust from emerging. The key is that the equipment to prevent the smoke and dust shall be designed and manufactured firmly, which will not affect the normal production and convenient use.

　　3. Shape of suction inlet and device position. It is necessary for the suction inlet to absorb more smoke and dust inside the steel pipe into the pipe to achieve the effect. A baffle shall be added in the future direction of the plasma gun cutting point to retain the smoke and dust inside the steel pipe, and it can be completely removed after a period of buffer.

　　Specific measures:

　　Put the dust baffle device on the traveling trolley inside the steel pipe and place it at the cutting point of the plasma gun about 500mm. After the spiral steel pipe is cut off, stay for a while to absorb all the dust. Note that the soot baffle should be precisely positioned in the cut-off position. In addition, in order to make the traveling trolley supporting the soot baffle and the spiral steel tube roll in accordance with each other, the traveling wheel angle of the traveling trolley must be consistent with the inner roll angle.

　　This method can be used for plasma cutting of large-diameter spiral welded pipe with a diameter of about 800mm; as for the pipe with a diameter less than 800mm, the smoke and dust with a small diameter can not be emitted from the direction of the pipe outlet, and it is not necessary to install internal baffles. However, there must be an external baffle to block the cold air at the smoke suction inlet of the shaper.

How to process galvanized steel pipe

　　Galvanized steel pipe is widely used in construction steel structure, car production, mechanical production, bridge construction, container keel, ship production and other fields because of its excellent corrosion resistance, deep processing formability, painting and weldability, as well as good surface quality and inductive mechanical function.

　　The processing of galvanized steel pipe is to accumulate a layer of metal or alloy on the surface of the product through the electrolytic process of metal ions based on the principle of electrolysis, so as to change the physical and chemical functions of the product surface, eventually making the galvanized plate have wear resistance, decoration and impact resistance.

　　The electroplating process of galvanized steel pipe mainly includes pretreatment, electroplating and post-treatment. The quality of the coating depends on the electroplating process of the material, and the electroplating process is affected by many factors. The six factors are summarized as follows:

　　1. Sodium hydroxide: sodium hydroxide has two layers of influence on the response. When its content is too high, it is easy to be burnt in the process of high temperature operation; when its content is too low, the solution will be poor in laxity, which will reduce the quality of zinc layer.

　　2. Iron content: when the iron content is too high, there will be more iron in the coating, which will lead to the lack of brightness of the passivation film of the product; and if the iron content is too low, it will lead to the low iron content in the zinc coating, which will reduce the corrosion resistance of the car board, and will lead to the olive color on the car board surface.

　　3. Temperature: too high temperature in the electroplating process will cause solution laxity to decrease, iron content in the coating will increase, and the passivation will be uneven; however, when the reaction temperature is too low, the high current density area will be slightly burnt, and the coating brittleness is large and the stacking speed is slow.

　　Cathode moving speed: it is necessary to ensure that the cathode is in the moving state in the electroplating process. If the moving speed is too fast, the coating in the high current density area will be rough in the electroplating process. If the moving speed is too slow, air flow may occur, resulting in uneven coating of materials

API 5CT oil casing and finished pipe process

　　After nearly 20 years of efforts, China's oil casing production from scratch, from low price to high price, from low steel grade to API series products, and then to non API products with special requirements, from quantity to quality, they are close to the level of foreign oil and casing products. The domestic market share of China's oil well tubing has exceeded 80%, and it has become a net export product for many years.

　　According to the regional distribution in China, the demand for oil and casing is no longer concentrated in the eastern region. From the perspective of the development trend of domestic oil and gas fields, the development of Daqing, Liaohe, Shengli and other Eastern oilfields has turned to the development of Western oilfields such as Sichuan and Xinjiang, paying attention to the trend of offshore oil fields. In addition, it will develop from land to beach and from shallow sea to deep sea. In addition, the drilling depth is getting deeper and deeper, and the drilling work is becoming more and more complex, and the requirements for oil and casing must be higher and higher.

　　Different types of casing used in the process of oil production: surface oil casing - protecting the well from being polluted by shallow water and gas layers - supporting wellhead equipment and maintaining the weight of other layers of casing. Technical oil casing - separate the pressure of different layers, so as to ensure the normal circulation of drilling fluid quota and protect the production casing. -In order to install anti burst device, leak proof device and liner in the well. Oil casing - oil and gas are transported from the reservoir below the surface. -Used to protect the well and separate the drilling mud. In the production of oil casing, the outer diameter is usually 114.3 mm to 508 mm.

　　The well head is protected by the weight of the casing in shallow water.

　　Technical oil casing - separate the pressure of different layers, so as to ensure the normal circulation of drilling fluid quota and protect the production casing. -In order to install anti burst device, leak proof device and liner in the well.

　　Oil casing - oil and gas are transported from the reservoir below the surface. -Used to protect the well and separate the drilling mud. In the production of oil casing, the outer diameter is usually 114.3 mm to 508 mm.

　　According to SY / t6194-96 "petroleum casing", oil casing can be divided into short thread casing and its coupling and long thread casing and coupling.

carbon steel pipe fitting