Monday, August 18, 2014

Mechanical expanding and hydraulic expanding characteristics

(1) the production of large diameter steel pipe aging rate. Because when you need to charge hydraulic expanding low-pressure water and then pressurized to achieve further boost when the steel yield. With the production of pipe diameter increases, the efficiency is greatly reduced, for example, pipe length 12m dollars, when 609.6mm (24in) diameter steel pipe hydrostatic expansion, 36 per hour, while the mechanical expanding, each Hour 28. Right 1067mm (42in) steel pipe, expanding the use of water pressure, 18 per hour, while 23 per hour when mechanical expanding. That mechanical expanding, not its efficiency and diameter size relationship, so relatively speaking diameter increases, the efficiency also high.

(2) easy to meet the stringent requirements of the inner diameter of the pipe. When laying long-distance pipelines, welded steel pipes installed in the field site, with an inner diameter of the base, the smaller inner diameter of the wrong side of two steel tube end after docking, transport resistance also smaller, so the pipe inner diameter of the dimensional accuracy requirements increasingly stringent, and the pressure outside the enlarged diameter of the die case is precisely controlled with pipe diameter, the inner diameter accuracy can not be guaranteed. Mechanical expanding head is inserted into the expanded diameter steel pipe were expanding, therefore, can control the pipe diameter size precision, regardless of wall thickness.

(3) good ovality. When the pressure expanding, because contact with the outer mold outer sleeve seam to the wall near the depression, the degree of damage to the oval steel tubes. When the expanding machine, as long as the weld head aligned with the enlarged diameter groove segments, expanded diameter when unconstrained weld area to form a smooth surface, thus effectively reducing the damage caused by the welded parts.

(4) the shape and size of the pipe end and high accuracy. Weld expanding effect when compared to both ends of the pipe need to push the conical indenter pressed against the head set in radial seal ring seal up, so steel tube end portion of the indenter in contact with the pipe flaring effect the tubular body portion inconsistent. The expanding does not have this phenomenon, good shape and size of the pipe end of the Field Installation and butt are favorable.

Tuesday, August 12, 2014

What is a steel pipe extrusion

The extrusion process is the heating of the ingot into the extruder barrel, the extrusion cylinder is placed at one end of the extrusion die, a pressure is applied to the other side, forcing the metal flow from the die orifice to produce a cross-section reduction, increasing the length plastic deformation method. Principle of the extrusion process, the first heated to a suitable temperature, to release the billet in the extruder barrel, extruder barrel at the end of the extrusion die is placed at the other end of the extruder barrel into the extruder barrel is slightly less than the pressing pressure washer, and then insert the shaft extrusion, extrusion shaft diameter smaller than the cylinder diameter 3 ~ 10mm. The pressure of the extruder through the extrusion axis, the metal billet is passed to the spacer, forcing the metal flow from the die hole, the hole size with the mold to obtain the shape of the same products. When the article is extruded hollow tube extrusion axis to an inner diameter of the pipe is determined by the punch pin. Wear larvae L needle is passed through the hollow shaft mounted on perforated extrusion systems extruder.

After the extruded steel pipe, first extrusion ingot axis by applying pressure to the pads, so that the metal tube full of extrusion, extrusion axis again after exiting some distance, then piercing needle to move forward through the ingot center and with the diameter of the extrusion die with a predetermined fit, is moved forward again after the extrusion axis, the pressure is transmitted to the billet forcing the annular gap between the metal of the mold formed by the punch pin hole and flows out to obtain the desired pipe. When the perforation, the central part of the metal billet to form a solid rod out from the die orifice to form the perforated first material. The degree of perforated material head size and full Extrusion ingots, diameter die hole piercing needle and relevant. At the end of extrusion, extrusion axis in the extrusion barrel remaining residual material that pressure more than the introduction of squeeze tube, by separating shears or hot saw the article and the pressure of more than cut off, and then by the separation mechanism will be pressed over the pad sheet separation, various tools and moving parts of the extruder to return the original state, the next pressing cycle.

Tuesday, July 15, 2014

Seamless coiled tubing manufacturing technology

Seamless steel coiled tubing is a kind of new oil pipe,several kilometers long, being bend repated,and generating plastic deformation many times. Coiled tubing and its operation equipments are called "universal operating machine". In foreign countries such as the United States, Canada and other countries, coiled tubing has become an essential oil equipment in oilfield operations. Currently the longest coiled tubing is 9000m long. And for this particular pipe, the core manufacturing technologies are as below:

1, The chemical elements
Due to the harsh environment,there are some higher requirements for the properties of the coiled tubing material mechanical and corrosion resistance. To optimize the design of the chemical composition of the material,we must also implement clean control of the whole process of smelting, rolling, etc, to minimize the containing of inclusions and S, P and other harmful elements.

2, Processing
after the combined effects of working hardening caused by the proliferation of dislocation and Bauschinger effects, take control of the transformation law of tube intensity.

3, Heat treatment
To achieve optimal control of microstructure and properties through the tube heat treatment, especially for the high strength and high ductility and low residual stress.

4, Welding Technology
For low carbon microalloyed steels, HFW welding technology is currently used. What need to study is the optimal welding parameters (such as current, voltage, frequency, welding speed, forming angle, extrusion volume, etc.), welds technology and weld heat treatment technology.

5, Plate butt
To achieve continuous production of HFW pipe, you must first take a long plate. Currently,butt plate is mainly using TIG, MAG and plasma welding methods. What is under study is friction stir welding methods.

6, Pipe butt
Coiled tubing may suffer local damage when in use, injury or defective parts must be cut off, and the rest parts are connected by welding. The traditional methods, which is commonly using manual TIG butt welding, but the welding quality is difficult to control, what is popular used currently is making automatic welding technology.

7, New manufacturing technologies
CVR technology, which uses a continuous tube of the same specifications, heated to 940 ℃ through online medium frequency induction and rolled by thermo-mechanical.On the one hand, to achieve seamless HFW weld optimization , on the other hand to achieve variable wall thickness or reducers. In addition, there are special stainless steel continuous tube laser welding technology.

Mine plastic pipe

Mine coated plastic tube have a wide range of uses in our life, some of its processing method are as below:
1, nozzle grinding:after cutting, Angle grinding machine should be used to polish the nozzle plastic layer, its purpose is to avoid to make plastic layer in flange welding melt even burning causing pipe damages.Using the grinder to polish the nozzle plastic layer.

2, grinding processing:when flange welding is completed, we should use the Angle grinder to make the nozzle smooth level off, may leave pits but no welding slag.

3, flange welding, after grinding, welding machine should be used to weld single flange and pipe together.Before welding,monolithic flange holes of single flange shall be corrected to avoid dislocation phenomenon during the connection process.

4, plastic coated treatment: polishing finished, using oxygen, acetylene on the outside of the pipe to heat pipe, heating to appear partial melting phenomenon inside plastic layer, then technical workers will use plastic powder prepared for nozzle to evenly daub, pay attention to it must be fully daub, plastic coated flange plate to daub to check above water line.This process should strictly control the heating temperature, if the temperature is too high,it will have the air bubbles in the plastic coated process, if the temperature is too low,  plastic powder will melt incompletely in the process of plastic coated, the above conditions will appear plastic layer falling off phenomenon after putting into use, in the end part of pipeline, steel pipe will suffer corrosion damage.

5, cutting: according to the actual required pipe length, pipe should be cut by metal saws or toothless saw .When using water in the process of cutting welding, there must be protection methods for raw materials. On both ends of fracture in the location of the cutting made baffle catches fire heat resistant material cutting down when sparks and hot molten iron beans, protect the original plastic raw material layer.

6, pipe connection: After fill plastic , connect and install the pipes and pipe fittings , add rubber mat in the process of connection between the flange, and fasten the bolt to seal condition.

Friday, July 11, 2014

Steel industry development in 2014

It is said that the steel industry has only just entering the winter, in the cold pressing of the environment, steel production accounted for 7.5% of the steel industry and naturally can not be spared. 2013, China's steel industry is still suffering from overcapacity, disorderly competition, torture and other diseases run profit. Branch in China Steel Pipe Association recently held its sixth meeting secondary members, steel branch chairman Li Qiang bluntly, the domestic steel production release faster, domestic production continued to show oversupply last year, steel prices up and low down run, industry profitability is still at a low level.

According to preliminary statistics, China has formed steel production close to 108 million tons, of which the production of seamless and welded steel pipe can be close to 43 million tons, respectively, and 65 million tons. 2013, China's steel production was 79.79 million tons, an increase of 5.686 million tons, an increase of 7.67 percent, down 0.79 percentage points from the growth rate over the previous year. Same period, the apparent consumption of steel was 71.208 million tons, an increase of 5.54 million tons, an increase of 8.44 percent, down 0.23 percentage points from growth. And an incentive overcapacity in steel industry concentration is low. According to statistics, China's seamless pipe production in the top 10 companies, and its production accounts for about 40 percent of the total production of seamless steel tubes; welded steel output of the top 10 companies, accounting for its production of welded steel and the total 20% yield. "Under the strict control of new capacity, expedite restructuring of steel enterprises, is the only way to improve the degree of concentration of seamless steel industry." Li Qiang think, according to the "steel industry" second five "development plan" 2015, for the top ten of seamless steel pipe production enterprises and 70% of the total production of seamless steel tubes. Which, for those who do not have the tube and strip (volume) of the company, should pay attention to the production of raw materials and steel enterprise restructuring, in order to obtain a stable tube and strip (volume) resources. This will not only facilitate the development of steel variety, improve product quality and ensure delivery, and can reduce steel production costs, enhance core competitiveness of enterprises.

Under low concentration of excess, will inevitably lead to business efficiency "shabby." Into the Lunar Year of the Horse, steel market did not "immediately brought the matter", steel prices did not "immediately bounce", but all the way down. As of mid-March, steel price index has dropped 89.11 points, the lowest price of all varieties of steel. "Space steel enterprise survival and development is undergoing a severe test of the steel industry is currently faced with an embarrassing situation: a leading technology and equipment, the production scale, product self-sufficiency rate, coverage expanded, industries are losing money, and a serious decline in the level of corporate profits.

The domestic market, "low-end" dogfight, China's steel exports have suffered a lot of obstacles. In recent years, China's steel products experienced foreign trade friction cases continue to increase, in addition to Europe and other developed countries, emerging countries and third world countries have started to implement the steel pipe from China's "double reverse" investigation. Earlier this year, the Eurasian Economic Committee intends to Chinese seamless OCTG countervailing investigation, prosecution and Russia TMK OMK Group. In addition, with Mittal, TMK production plant in Saudi Arabia, the Middle East, or will Chinese steel products as a "dual" goal, China's steel export outlook is not optimistic. It is worth mentioning that in 2013, China's steel export price of $ 1,209 / ton, steel import price at $ 4,006 / ton; although the import and export price has declined, but the average import price of steel exports are still 3.31 times the price, the average price difference of $ 2,797 / ton.

Due to the world for the revitalization of the national economy, protect local businesses and promote employment, constantly resorted to trade protectionism banner, the difficulty of increasing steel exports. 2013 net export volume of steel was 8.58 million tons, an increase of 1.68 percent, down 5.16 percentage points from growth. This is our country since 2003 to become a net exporter of steel since the first export volume increased slightly but the growth slowdown appears. 2014 will be more in the future will show a normal trend, steel companies must have a full mental preparation and marketing measures, and actively respond to the "double reverse" survey of China's steel products trade friction encountered. The pattern of China's steel industry profit this year, running is still difficult to change. On the one hand, the price of imported iron ore and steel price movements showed asymmetrical running posture, namely steel prices, with ore prices rose; However, when steel prices, ore prices only fell behind, and the decline is relatively small. Expects iron ore prices are still high, and showed soaring trend of slow down, so that weak steel prices rebound. On the other hand, with the national increase energy conservation efforts, resources, energy, environment and transportation prices, fiscal reforms accelerated, steel production costs will be further enhanced.

It is foreseeable that in the operating profit of the situation, the steel industry transformation and upgrading, will accelerate the pace of structural adjustment. Upgrade and change First, resolve excess capacity, improve quality and efficiency. With the gradual slowdown in China's economic growth rate, the demand for steel market growth will be slowed, steel market will be long-term in a situation of oversupply, and resolve conflicts pipe serious excess capacity, must take positive and effective measures to seriously implement the "group of four" requirements, to promote enterprise development mode transformation, turning variety, quality and efficiency from economies of scale, improve the quality of enterprise reform and innovation through the country. Second, identify the product positioning, expand competitive advantage. The current status of the steel industry is a lack of high-end products, the low-end surplus products. For this reason, not only to increase oil production, electric power, aerospace, defense, chemicals, energy, heavy walled structures, machinery and other fields with a special high-end seamless and natural gas project, undersea pipelines, pipelines and other mega projects field seamless steel pipe with a special high-end research and development efforts; imported products also aim at "replacement" of product development. Third, speed up environmental governance, to achieve green development. Steel industry must accelerate backward, strict implementation of environment standards, and strengthen environmental protection and other legal constraints, and actively develop recycling economy, low carbon development. Finally, even with their own advantages, do the fine steel main industry, the scientific development of non-steel industry, and to speed up the "going out" pace of implementation of international strategy layout.

Welded pipe prices trendency

The price of domestic welded steel pipe continues to fall recently, which is particularly prominent in North China area, Tangshan is the main representative . In June, welded steel pipe prices have been followed by the reduction in strip steel prices fell after the settlement conference, strip prices despite a rebound, but the price of welded pipe did not immediately follow up with signs,, what is the reason for such a trend for welded pipe prices? Here to make a specific analysis:

Firstly, the Steel market is still in the off-season, multiple high temperature and heavy rains, outdoor operating situation has not improved also. Engineering projects remain small, limited end-user demand, few stocking, and excessive inventory will also cause backlog in the pipe factory.

Secondly, in the background of the whole industry being at a loss, many large trader dealers are reducing their inventories, and some smaller agreement clients choose the operation mode shipping directly from steel household not taking inventory of steel to avoid risks. Besides,with the strict limits to bank loans for the steel industry , many traders find it difficult to survive here.it would be difficult to achieve a breakthrough If there is no support of national policy,, the latter situation is still not  optimistic.

Thirdly, although have the intention to control the inventory and avoid becoming a drag on stock funds , once the market improves, increase production, steel mills control action on the power loss in the collapse, is a "temporary solution"

To sum up: steel mills to take reasonable measures to control inventory, but for the price adjustment is not positive, most think the price adjustment action to stimulate the turnover is limited, so to stabilize the main quote. Further plants are considered excessive tube and steel pipe price spread between the price decrease in profit margins narrowed, there is not enough profit, few companies are willing to loss Paohuo. In the case of weak demand, welded pipe market is difficult to quickly reverse the vulnerable situation, there is no real price rally conditions. Short-term pipe prices still weak consolidation, Change dilemma appears.

Wednesday, November 27, 2013

Precision tube rusting reasons and how to avoid the rusting way

Introducing performance precision tubes, precision tubes often said that it is not easy to rust, and say this is because of the precision tubes containing chromium ingredient, in the air, it combines with oxygen to form a solid surface and dense film is not oxidized state, this film is not oxidized steel surface to prevent oxidation (rust), and may play a role in protecting the surface to prevent corrosion of various corrosion factors. However, if this layer of protective film destroyed, its corrosion occurs, let's look at what causes for the oxide film is destroyed and its corresponding approach.

The main reason for the destruction of the oxide film from its floating iron or harmful atmospheric gas composition affected, because adhesion, accumulation, and sea salt contained in the adhesion caused. These attachments will gradually gather, plus moisture and fixed, so that will destroy the surface of the stainless steel pipe materials are not oxidized film and hinder regeneration of this film, which began rusting stainless steel pipe materials. Rust caused by this situation, mainly precision tube surface rust inside and no rust, so the direct use of artificial means to get rid of surface rust can, once the rust removal, precision tubes can still restore the original shiny, re-use.

For precision tubes are often not in use, before use, when found rusted, they need to be cleaned, in peacetime, we should pay attention to the maintenance of precision tubes, precision tubes not only to avoid corrosion, but also to save a lot of waste of human and financial resources for our business, after all, under the rusty precision tubes if the number of its relatively large number of cases, cleaning up is also a troublesome thing.