Steel - high chromium cast steel bimetallic composite pipe, due to its composite properties, the inner layer of high-chromium cast steel material, so that its hardness can reach 40HRC-60HRC, the outer layer of ordinary cast steel material, has good mechanical impact resistance, Thermal shock performance, widely used in the coal industry, coal washing plant coal handling, ash transport, slag system, power plant ash removal system.
Steel - high-chromium cast iron bimetallic composite pipe is a new type of wear-resistant pipe developed by our company. The outer straight pipe is made of ordinary steel pipe and is formed by compounding of high-chrome cast iron lining by centrifugal forming process. Bending pipe wall with hot simmer elbow, the inner cast high chromium cast iron. Compared with the traditional wear-resistant alloy cast iron, wear-resistant alloy cast steel, steel-ceramic composite pipe and cast stone pipe, the pipe has many advantages.
Excellent features: good wear resistance, give full play to the wear resistance of high-chromium cast iron. High pressure, can be applied to any pressure level. The inner lining is tightly combined with the outer steel pipe, and the special process is adopted to form the welding between the composite layers to ensure the operation reliability. Has good resistance to mechanical shock, thermal shock performance, easy installation and connection. Can be flanged, flexible joints, can be cut, welded.
Applications: Power plant pulverized coal conveying system, dry ash pipe; thermal power plant stone coal system; bimetallic composite pipe is mainly used in civil construction and drainage, fire protection, HVAC, solar energy, food, chemical, petroleum and other fields .
Domestic and foreign wear-resistant pipe status: In electric power, mining, metallurgical and other industries, material delivery, output, are the use of close, high pressure transport, the pipeline under considerable pressure, and subjected to very serious wear and tear, a single material Pipeline is difficult to meet the requirements of this condition, especially the elbow, due to its use of safety, and service life, with emphasis on improving the liner ductility, impact resistance, and wear resistance. Also consider the overall strength of the pipe and elbow. The domestic and foreign common use of A316Mn seamless steel pipe, resulting in serious pipeline wear, frequent replacement, a more mature cast stone Although the cast stone itself has a higher hardness, but due to process reasons, the larger the thickness of cast stone , Silly, big, stupid, rough, in the use of a great restriction. In addition, the brittle stone more easily broken, to the delivery and installation of great difficulties. Some research institutes and manufacturers to produce composite ceramic steel pipe, but there are many shortcomings, easy to fall off, failure phenomenon, in the high temperature and pressure and the material contains some harmful elements such as sulfur. Prone to high temperature oxidation. Can not meet the existing operating conditions.
According to long-term production system, in many failures summed up, more reasonable scientific new experience, adding a certain amount of rare earth elements to improve the quality of steel alloy. Also play a role in refining the grain; the formation of a protective film on the surface; adding a certain amount of Mo alloy at a certain temperature, has a certain antioxidant effect, increase service life; add a certain amount of boron carbide, the hardness control HRC45 ~ 65 Of the range, at the same time to solve the hardness of the wear-resistant steel and solderability of the conflict between, with high wear resistance, wear-resistant materials in other applications can not be compared with its beauty. Other powder body pneumatic conveying system; Hydraulic slag conveying system and larger size slurry conveying.
Steel - high-chromium-nickel alloy composite pipe by the outer wall and the liner compound, the outer wall of 5-12mm thick seamless steel pipe, lined with 6-25mm thick high-chromium nickel alloy, straight pipe using centrifugal composite, elbow vacuum negative Forging from pressure, the product takes full advantage of the pressure capacity of seamless steel tubes, welding performance and high-chromium-nickel alloy high hardness (HRC55 ~ 60), is an ideal wear-resistant pipe.
Wear-resistant pipe, including wear elbow, straight pipe, tee, size head, radius section, adjustable tube and other structural parts, mainly for pneumatic, pumping slurry and other material pipe. As the transmission medium with high hardness, fast flow, large flow rate and other characteristics, can effectively reduce the transmission medium on the long-term continuous impact on the wall, wear, corrosion, resulting in pipe fatigue resulting gradually worn out of the speed.
Transportation has been throughout the power, metallurgy, coal, petroleum, chemical, building materials, machinery and other industries, and the rapid development. When the wear-resistant pipe transport abrasive materials (such as ash, pulverized coal, mineral flour, tailings, cement, etc.), there is a wear-resistant pipe wear fast problems, especially elbow wear faster . When a strongly corrosive gas, liquid or solid is transported inside a wear-resistant pipe, there is a problem that the wear-resistant pipe is corroded and quickly destroyed. When transporting materials with higher temperatures in wear-resistant pipes, there is a problem that the use of heat-resistant steel pipes is very expensive. After the wear-resistant pipe market, these problems are solved. Wear-resistant pipe is widely used in severe wear and tear mine fillings, ore and tailings delivery, coal-fired power plant to send powder, slag, ash and other wear-resistant pipe is also very suitable. Wear pipe is strongly acid corrosion, acid, alkali, salt and abrasion of both solid, liquid delivery of the ideal wear-resistant pipe. Wear-resistant pipe in the high temperature corrosion, high temperature wear or high temperature corrosion in the case of the use of very safe and reliable.
Steel - high chrome-nickel double-metal wear-resistant pipe features:
1, good wear resistance:
The composite tube lined with high-chromium nickel alloy, hardness HRC55 ~ 60, is a highly wear-resistant materials. The use of special compound modifier grain refinement, greatly improving the product's toughness, tensile strength. Elbow eccentric production, wear resistance is much better than steel - ceramic composite pipe.
2, under pressure:
The outer wall of the product adopts seamless steel pipe, which is a hub technology with large bearing pressure. It is lined with high-chromium nickel alloy to resist abrasive wear without being under high pressure. Compared with rare earth wear resistant steel pipe and steel-ceramic composite pipe, the product can guarantee safe operation Combined for high pressure, high concentration, long distance pipeline delivery.
3, high temperature:
Lined with high-chromium nickel-nickel alloy can be applied under the premise of 600 ℃ without deformation, oxidation, and maintain a high wear resistance.
4, good erosion resistance:
High chromium-nickel alloy 5% or less of sulfuric acid, hydrochloric acid, hydrofluoric acid, caustic soda corrosion resistance up to 99%.
5, good appearance, anti-fouling:
The appearance of the product using seamless steel tubes, the appearance of the product quality has greatly improved, after installation can improve the engineering standards, the use of centrifugal and vacuum lining forging, wall smooth, greatly improving the anti-fouling ability of the pipeline.
6, install convenient:
Outer wall seamless steel pipe series specifications, greatly facilitate the design and installation of pipe fittings, while welding performance, welding, flange connection.
Steel - high chrome nickel dual-metal wear-resistant pipe main application areas:
Thermal power plant pulverized coal transportation system, wet and dry gray pipe, stone coal system
Other powder power delivery system
All kinds of mine material transport
Hydraulic slag delivery system and larger size slurry delivery
skills requirement
Bimetallic composite tube diameter deviation: single tube diameter deviation of 0 ~ + 1%.
Concentricity deviation: single tube at both ends concentricity ≤ 1mm / m.
Both ends face parallel, should be perpendicular to the centerline.
Metal wear elbow and both ends of the transitional section takes over the ovality should meet the acceptance requirements of the state and industry (≤ 5 ‰).
Lined surface smooth, no edge, no flash, no burr, with sand and cold iron and so on.
Pipe fittings shall not affect the mechanical properties, use requirements, the appearance of quality slag, loose, cracks, cellular pores and other defects.
Pipe fittings in accordance with the drawings provided by the demand side and the list of requirements. The buyer is responsible for the specifications of the drawings provided, and the supplier ensures that the processed products conform to the geometric tolerances of the drawings.
Pipe fittings weight tolerance in accordance with GB / T11351MT10 implementation.
All pipe fittings have been pressure tested to ensure on-site installation without leakage.
Technical quality assurance
Equipment delivered to the construction site is guaranteed to be complete and brand new.
Straight pipe to ensure that the service life of more than 6 years.
Warranty: installation test run after a year of acceptance.
Provide inspection reports of composite pipe, including product quality assurance and product certification and other detailed information, such as the appearance of product quality and technical problems, the supplier bear the corresponding loss.
Provide welding and the overall composite pipe drawing test, hardness testing, metallographic analysis of the content of the report.
The inner and outer diameter and wall thickness of the bimetallic composite pipe shall not exceed the national standards, the port of the composite pipe shall be smooth, and the plane of the port shall be perpendicular to the inner and outer walls of the anti-wear pipe to be favorable for contact and welding.
The construction site to arrange someone to guide, to ensure that the installation process of composite pipe wear-resistant tube is not deformed, does not fall off, does not break, to ensure foolproof.
Common four bimetal wear-resistant steel pipe processing technology
Common bimetal composite wear-resistant steel surface treatment technologies include surface bleaching, surface mirror bright treatment, surface coloring treatment has the following treatment:
Surface color bleaching: bimetal composite wear-resistant steel pipe in the process of processing, after the coil, bar edge, welding or heat roasting artificial surface, resulting in black oxide skin. This hard black oxide mainly NiCr2O4 and NiF EO4 two components, the former generally used hydrofluoric acid and nitric acid to remove the strong corrosion method. However, this method is costly, polluting the environment, harmful to human beings and is more corrosive and gradually being eliminated.
Currently there are two main ways to deal with scale:
Sand blasting (pill) method: The main method is to use spray glass beads to remove the surface of the black oxide.
Chemical method: Use a non-polluting pickling passivation paste and non-toxic room temperature non-toxic cleaning agent with inorganic additives for dipping.
So as to achieve the bimetal composite wear-resistant steel pipe whitening treatment purposes. After handling basically looks a dull color. This method is suitable for large and complex products.
Bimetallic wear-resistant steel pipe surface mirror Bright treatment: According to the complexity of bimetallic wear-resistant steel pipe products and user requirements may be different using mechanical polishing, chemical polishing, electrochemical polishing and other methods to achieve the mirror gloss.
Surface coloring: Bimetallic wear-resistant steel pipe coloring not only gives a variety of colors of bimetal composite wear-resistant steel pipe products, increase product color varieties, but also improve product wear resistance and corrosion resistance. Bimetal composite wear-resistant steel pipe has a unique strength, high wear resistance, superior corrosion resistance and not easy to rust and other excellent features. It is widely used in chemical industry, food machinery, electrical and mechanical industries, environmental protection industry, household appliances industry and home decorating, finishing industries.
Power plant double metal wear-resistant steel pipe life
Bimetal composite wear-resistant steel pipe mill power plant generally used at the entrance, due to the working fluid (coal block) relatively large, strong impact on the process of falling coal abrasion outer wear of the pipeline is serious, the inner arc Part of no wear. According to this use of the environment, our company developed a dedicated dual-metal wear-resistant steel pipe.
1, bimetal composite wear-resistant steel pipe According to the design requirements of the outer steel body, the outer wall of the steel outer wear-resistant layer need to do part of the welding hanging point, making the wear-resistant layer can be firmly posted in the bimetal composite wear-resistant steel pipe wall.
2, the production of lost mode abrasives, outer wear layer of the thickest part of the thickness of 40mm, slowly thinning on both sides, the thinnest at 20mm, with the pipe outside the arc as the center point to both sides of the pipe wall to expand 105 ° -100 ° , Will disappear pattern clothing in the pipe wall outside the arc part of the brush and drying.
3, the dried finished products will be buried in the casting sand, XZTBCR28 casting, natural cooling after casting is completed, the repair part of the uneven and burrs, paint, do marking.
4, the advantages of dual-metal composite wear-resistant steel pipe: For various parts of the pipeline wear, using a unique design to extend the service life of dual-metal wear-resistant steel, making the life of dual-metal wear-resistant steel pipe in about 20 years, Reduce the weight of bimetal composite wear-resistant steel pipe, greatly lower the cost of input costs. XZTBCr28 material guarantee excellent wear resistance, a unique design to solve the bimetallic wear-resistant steel wear-resistant layer of steel off problems.
Preparation of bimetal composite wear-resistant steel pipe - centrifugal casting and centrifugal aluminum
Centrifugal casting is developed to adapt to offshore oil and gas production and is suitable for the manufacture of composite pipes with a lower melting point than the outer metal. Lining and substrate are made of liquid metal. The outer tube of molten steel is introduced into a rotating mold, the outer tube during solidification monitoring tube temperature. When the outer tube solidified and reached a certain temperature, poured into the inner metal corrosion-resistant alloy. By controlling the casting conditions, it is possible to produce a bimetallic composite wear-resistant steel tube that is strongly metallurgically bonded.
When applying liquid metal for surface deposition, the use of centrifugal technology to eliminate the complex layer of pores and inclusions prone. At this time, the lower density slag, the impurities and the gas in the molten metal rise to the surface, while the heavier metal component sinks to form a dense layer on the pipe wall, thereby improving the quality and reproducibility of the weld. So its advantages and disadvantages are:
1, Advantages: Metallurgical interface to achieve high density, slag, exhaust good.
2, Disadvantages: If there is no subsequent thermal deformation, limited to the use of as-cast, the coarse as-cast structure resulting in mechanical properties of various layers of metal can not give full play. In addition, the method can not produce a composite steel tube with a light alloy outer layer.
Centrifugal aluminothermic method is also known as shs-centrifugal method, shs is an abbreviation for self propagating high temperature synthesis. Centrifugal pyrometallurgy is the essence of the thermal field in the centrifugal force caused by aluminum reaction, the so-called thermite reaction is the aluminum metal powder and other metal oxide powder mixed together, through the ignition occurred very rapid exothermic reaction (mo + al → m + al2o3 + q). The reaction adiabatic temperature can be close to 3000k, so the products are in liquid state, under the action of centrifugal force, the products with large specific gravity such as fe, cr, ni etc. are concentrated near the inner wall of the carbon steel pipe to form a lining metal layer; al2o3 forms the innermost residue , By mechanical methods to remove, then prepared bimetallic composite wear-resistant steel pipe.
Centrifugal casting + hot extrusion (hot extrusion + cold rolling) method
"Centrifugal Casting + Hot Extrusion" is a new method for preparing short pipe of composite pipe. The hollow composite pipe is manufactured by centrifugal casting, and then heated, hot-extruded or hot-extruded and cold-rolled, and subsequent heat treatment to obtain the finished product Composite pipe. It effectively combines the advantages of both centrifugal casting and hot extrusion methods to shorten the production process and achieve complete metallurgical bonding of the composite interface. Its uniqueness is that he combines primary industrial materials with high-tech metallurgical processes by adopting techniques such as centrifugal casting technology, plastic thermal compounding technology such as hot extrusion, cold-rolling (or cold drawing) production methods and high-quality composite Pipe.
Explosive welding forming method
Explosive welding molding process is based on blast shock explosions, plastic deformation of the inner tube, close to the outer tube, forming a composite tube. The use of explosive molding, the coating can be less than 0.2mm, the fusion ratio can be as small as 5%; coating tight, wide product applicability. In addition, the use of explosion welding can be achieved a variety of metal connections, and some can not be achieved using other methods. The main disadvantage of this method is that the interface non-diffusive metallurgical bonding is difficult to accurately determine the explosive volume of the long composite tube and has some risks.
Powder metallurgy method
In the carbon steel or similar materials made of metal tubes and thin-walled tube between the filler layer, the tube ends were sealed with a floor. Heated at a predetermined temperature, and then hot extruded into a composite steel pipe. With pickling method to remove the floor and metal thin-walled tube. Depending on the application, the composite layer can be the outer or inner layer.
Laser cladding method
High-power laser equipment to cover the steel pipe. The alloy powder is sent to the laser beam irradiation area of the mother pipe by the automatic feeder. After the laser beam melts the powder and the surface of the workpiece, the whole steel pipe can be completely covered by a spiral coating method to form a bimetal composite wear-resistant steel pipe .
Wear-resistant alloy bimetallic composite pipe in line with the current use of the relevant national standards and ministerial standards. These standards and specifications include:
GB223, "Methods for Chemical Analysis of Steel and Alloys"
GB228, "metal tensile test method"
GB229, "Metal Charpy impact test method"
GB230, "Metal Rockwell hardness test method"
GB241, "Metallic pipes hydraulic test method"
GB / T13298, "metal microstructure test method"
DL / T680, "wear-resistant pipe technical conditions"
