Concept: seamless pipe is a kind of hollow, no seams around a strip of steel. According to different production methods can be divided into hot-rolled pipes, cold rolling mill, cold drawn tubes, extruded tubes, etc.
Main category:
Type of stainless steel tube:-rolling hot-rolled, hot-extrusion and drawing (rolling) of stainless steel tubes.
Stainless steel microstructure-different semi-semi-Markov systems of ferrite stainless steel pipes, Martensitic stainless steel, austenite system stainless steel tubes, austenitic-tiesutie stainless steel pipe and so on.
Stainless steel pipe specifications and quality:
A, according to the GB14975-94 provisions of the stainless steel seamless pipe, steel pipe lengths usually (indefinite) hot-rolled steel 1.5~10m, hot extrusion pipe equal to or greater than 1M. Drawing (rolling) wall thickness 0.5~1.0mm, 1.0~7m; the wall thickness is greater than 1.0mm, 1.5~8M.
B, hot-rolled (hot extruding) the diameter of the steel tube 54~480mm total 45; thickness 4.5~45mm total 36. Drawing (rolling) of the diameter of the steel tube 6~200mm total 65; thickness 0.5~21mm total 39.
C, inside and outside the pipe surface without cracks, collapse, cracking, cracking, folding, rolling and scabbing defects exist, which should be completely removed (except for machining tubes), cleared that the wall thickness and outside diameter shall not exceed tolerance. Other minor surface defects does not exceed the allowed tolerance is not clear.
D, allows the depth of the straight. Hot-rolled, hot-extruded steel, diameter is less than and equal to 140mm is not greater than the nominal wall thickness of the 5%, the maximum depth is not greater than 0.5mm; cold drawing (rolling) of the nominal wall thickness of the pipe not more than 4%, the maximum depth is not greater than 0.3mm.
E, both ends of the pipe should be cut at right angles, and remove burrs.
Stainless steel seamless pipe manufacturing processes:
1. hot-rolled (squeeze seamless steel tubes): round tube perforation → → → heated three-roll cross rolling, continuous rolled or extruded-cannula → sizing (or reducing) the straightening → → → cooling water pressure test (or testing) → tags → storage
Rolling of seamless pipe material is round the tube, tube embryo to undergo the cutting machine cutting billets into lengths of about 1 m, and the conveyor belt to the furnace heats up. Billet is fed into a furnace heating temperature of about 1200 degrees Celsius. Fuel for hydrogen or acetylene. Furnace temperature control is the key issue. circular tube due to stress after piercing wear empty. Generally more common Mole is cone shaped roll piercer, this punch high production efficiency, product quality, and perforation of expanding capacity, can be worn a variety of steel grades. After the punch, round tube has been three-roll cross-rolling, rolling or extrusion. Extrusion pipe sizing. Sizing machine with a conical drill drilling of high speed steel embryo, forming tube. Outside diameter of the pipe inner diameter sizing machine drill bit length to determine. After sizing, it tube into the cooling tower through cooling water, after cooling, it tube, will be straightened.
2. cold drawing (rolling) seamless steel pipe: round tube perforated → heat → → → → start → annealing pickling oil (copper) → multi-pass drawing (cold rolled) steel tube heat treatment straightening → → → → hydrostatic test (testing) → tags → storage.
Drawing (rolling) seamless steel pipe rolling method of hot-rolled (squeeze seamless steel tubes) complex. Their production process steps are basically the same. Differences from the fourth step, after empty, it tube, to start annealing. After annealing with a special acid pickling. After pickling, oiling. Then is a multi-pass drawing (cold rolled) steel tube special heat treatment. After heat treatment, must be straightened. After straightening, it tube sent by conveyor belt to the crack detection machine (or pressure) for internal testing. If the pipe cracks, bubbles and so on, will be detected. Pipe inspection also strict hand-selected. After a steel pipe inspection, sprayed with paint numbers, specifications, production batch, and so on. And by crane into the warehouse.
Basic criteria:
1. seamless tubes for structures (GB/T8162-2008) is a seamless tubes for general structure and mechanical structure.
2. seamless tubes for fluid transport (GB/T8163-2008) was used to carry water, oil, gas and other fluids generally seamless.
3. low/middle-pressure boiler seamless steel pipe (GB3087-2008) is used in the manufacture of low and medium pressure boiler steam pipes, tubes in boiling water and superheated steam locomotive boiler pipes, drag pipes, small pipes and arched brick pipe hot-rolled quality carbon structural steel and drawing (rolling) seamless tubes.
4. high pressure boiler seamless steel pipe (GB5310-2008) is used in the manufacture of high pressure and the pressure of water-tube boiler heating surfaces with high quality carbon steel, alloy steel and stainless steel seamless pipe.
5. chemical fertilizer plants with high-pressure seamless tube (GB6479-2000) is suitable for working temperature is-40~400℃, the working pressure is 10~30Ma chemical equipment and pipeline of high quality carbon steel and alloy steel seamless pipe.
6. seamless pipe for oil cracking (GB9948-2006) is applied to oil refinery furnace tubes, heat exchangers and pipes seamless pipes.
7. geological drilling pipe (YB235-70) is used for core drilling by the Geological Department of steel pipes, can be classified by use of the drill pipe, drill collars, core pipe, casing, and settling tube.
8. seamless tube for diamond core drilling (GB3423-82) is used for diamond core drilling pipe, the core rod, seamless casing.
9. oil-drilling pipe (YB528-65) is used for oil drilling ends within the thickened or plus thick seamless pipes.
10. carbon steel seamless pipe for ship (GB5312-85)
China classification society and welding materials--China classification society (CCS)
Norway Det Norske Veritas (DNV) specification--Norway Det Norske Veritas (DNV)
United Kingdom Lloyd classification society (LR) specifications--United Kingdom Lloyd classification society (LR)
Germany Lloyd classification society (GL) specification--Germany Lloyd classification society (GL)
United States classification societies (ABS) specifications--United States classification societies (ABS)
France Det Norske Veritas (BV) specifications--France Det Norske Veritas (BV)
Italy classification societies (RINA) specifications--Italy classification societies (RINA)
Japan classification societies (NK) specifications--Japan classification societies (NK)
I-level pressure pipe is manufactured ships, ⅱ class pressure piping, boiler and superheater for carbon steel seamless pipe. Carbon steel seamless pipe wall temperature does not exceed 450 ℃, alloy steel seamless pipe wall temperature over 450 ° c.
11. seamless tubes for automobile axle (GB3088-82) was manufactured car axle and driven bridge shell axis effective quality carbon structural steel and alloy steel hot-rolled seamless pipes.
12. the diesel used high-pressure tubing (GB3093-86) is to create diesel injection system of cold-drawn seamless tubes for high pressure pipe.
13. precision hydraulic and pneumatic cylinder diameter seamless pipe (GB8713-88) is a manufacturer of hydraulic and pneumatic cylinder with precision for dimension of inner diameter of cold-drawn or cold-rolled precision seamless tubes.
14. cold-drawn or cold-rolled precision seamless pipe (GB3639-83) is used for mechanical structures, hydraulic equipment, high precision and good surface finish of cold-drawn or cold-rolled precision seamless tubes. Use seamless precision manufacturing of mechanical or hydraulic equipment.
15. stainless steel seamless tubes for structures (GB/T14975-2002) is widely used in chemical, petrochemical, textile, medical, food, machinery and other industrial corrosion of piping and structural parts and components made of stainless steel and hot-rolled (squeeze, expansion) and drawing (rolling) seamless tubes.
16. the fluid transport stainless steel seamless pipe (GB/T14976-2002) is used for conveying fluids made of stainless steel and hot-rolled (squeeze, expansion) and drawing (rolling) seamless tubes.
17. shaped seamless tube is in addition to tube section other than of seamless pipes in General. Steel of different shape and size can be divided into equal thickness shaped seamless pipe (code d), unequal thickness shaped seamless (code-named BD), variable diameter shaped seamless pipe (code named BJ). Special shaped seamless tubes are widely used in various structures, tools, and machine parts.
18. the low-temperature pipeline seamless pipe (GB/T18984-2003) is used for level-45 ¡æ ~-195 ¡æ pipes for low temperature pressure vessels and heat exchangers seamless steel tube for pipe
Seamless pipe is made of 10, 20, 30, 35 and 45 high quality carbon structural steel 16Mn, 5MnV or low-alloy structural steel 40Cr, 30CrMnSi, 45Mn2, 40MnB, alloy structure made of steel, hot-rolled or cold-rolled. 10, 20, made of low carbon steel seamless pipes are mainly used for fluid pipelines. 45, 40Cr, carbon steel seamless pipe used in the manufacture of mechanical parts, such as automotive, tractor mechanical parts. Flattening test for seamless steel tubes to ensure strength and. Hot-rolled steel hot-rolled or heat treatment State delivery cold rolled steel to heat to heat delivery. Low and medium pressure boiler seamless steel tubes: used in the manufacture of low and medium pressure boilers, steam pipes, water pipes, water wall tube locomotive boiler superheated steam pipes, drag pipes, small pipes and arched brick pipe, etc.
Quality carbon structural steel, hot-rolled or cold-rolled (a) seamless pipes. Used steel, 10, 20th, in addition to ensuring chemical composition and mechanical properties to do pressure testing, crimping, expanding and flattening tests. Hot-rolling hot rolling condition delivery, cold rolled (dial) to heat treatment delivery.
Seamless management on the weighing mode: seamless management on the calculation formula: (outer diameter – wall thickness) x0.02466= x wall thickness seamless pipes per metre weight {kg}
Chemical composition:
1, according to chemical composition and mechanical properties of the supply of domestically produced seamless tubes, such as 10, 15, 20, 25, 30, 35, 40, 45 and 50th of the chemical composition of steel shall conform to the provisions of GB/T699-88. Standard inspection of imports of seamless pipes according to the contract. 09MnV, 16Mn, 15MnV, the chemical composition of steel shall conform to the provisions of GB1591-79.
2, specific analytical methods according to GB223-84 of the iron and steel and alloy chemical analysis method of part of the building.
Analysis deviation 3, reference to GB222-84 the chemical analysis of steel samples and chemical tolerances of finished products.
Physical properties:
1, according to property the supply of domestically produced seamless tubes, ordinary carbon steel GB/T700-88 steel manufacture (but must ensure that the sulphur content of not more than 0.05% and phosphorus content of not more than 0.045%), the mechanical properties should conform to the values set out in the GB8162-87 table.
2, supplied by water pressure test of Chinese-made seamless standard hydrostatic testing must be guaranteed.
3, imports of seamless physical performance test carried out according to the standards stipulated in the contract.
Uses:
1, seamless pipe use is very extensive. General purpose seamless tube made of ordinary carbon structural steel, low-alloy structural steel or alloy structural steel rolling production, mainly as a transmission fluid pipe or structural parts.
Supply of 2, depending on the uses fall into three categories: a, supplied by chemical composition and mechanical properties; b, according to the mechanical properties of supply; c, supplied by the hydraulic test. Press a, b class supply of steel pipes, such as a liquid under pressure, and water test.
3, special-purpose seamless tube boiler seamless steel pipe, geology and seamless pipe and seamless pipe for oil and so on.
Category:
1, according to different production methods can be divided into hot-rolled seamless steel pipe pipe, cold rolling mill, cold drawn tubes, extruded tubes, etc.
2, classified by shape round tube, profiled tubes of the points. Special tube except for square and rectangular tubes, and oval tube, half pipe, triangle tube, and convex-shaped hexagonal tube, plum-shaped tubes.
3, according to the different material, divided into ordinary carbon structural tubes and low alloy structural tubing, high quality carbon structural tube, alloy tube, stainless steel pipe and so on.
4, according to specific purposes, boiler tubes, geological pipe, oil pipe, and so on.
With a wide range:
Fluid pipes, boiler factory, engineering, machinery and plant.
Production process: seamless tube size: 6-1240x1-200mm
Process flow
Tube billet--test--peeling--test--heating--perforation--pickling--repair mill--lubrication dried--welding head--drawing--solid dissolved processing--pickling--pickling passivation--test--cold rolled--to oil--cut head--dried--within polishing--outside polishing--test--identifies--finished packaging
Manufacturing process
Hot rolled, cold drawing, thermal expansion
According to different production methods can be divided into hot-rolled pipes, cold rolling mill, cold drawn tubes, extruded tubes, etc.
1, hot-rolled seamless pipes generally manufactured on automatic rolling unit. Check for and remove solid billet surface defects, cut into desired lengths, centering on the perforated tube end to end, and then sent to the furnace heat, perforated in the punch. Piercing while continuing to rotate and move forward, in rolls and head under the formed cavity within the tube, capillary. Then sent to the automatic mill continued to roll on. Finally the whole wall thickness, warp sizing machine sizing, meet the specification requirements. Production hot-rolled seamless steel tube continuous rolling method is more advanced.
2, if you desire to get better quality and smaller size of seamless pipe, cold rolling, cold-drawing must be used or a combination of methods. Cold rolling is usually conducted in two-roller rolling mill, steel tapered round slot and fixed cone composed of the head of the ring groove rolling. Cold drawn usually in 0.5~100T single-chain-or double-stranded in the cold-drawing machine.
3, extruding tube to be heated in a closed extruded cylinder, perforated bar movement with the extruded rod, extruded parts extruded from a smaller die. This method can produce a smaller diameter pipe.
Specifications: seamless pipes provided by GB/T8162-87
1, size: hot-rolled tube outer diameter 32~630mm. 2.5~75mm wall thickness. Cold rolled (cold drawn) outer diameter 5~200mm. 2.5~12mm wall thickness.
2, surface quality: inside and outside surface of the pipe without fracture, fold, roll fold, separation, hairline and scarring defects exist. These shortcomings should be completely removed, cleared that the wall thickness and outside diameter shall not exceed tolerance.
3, both ends of the pipe should be cut at right angles, and remove burrs. Wall thickness is greater than 20mm pipe allows gas cutting and hot saws. Supply and demand may also by mutual agreement without removing the head.
4, cold-drawn or cold-rolled precision seamless steel tube of the surface quality of the reference GB3639-83.
Packing provisions:
Provided by GB2102-88. Pipe packing in three: banding banding, packing, oiling or greasing packing. Steel is a kind of hollow, no seams around a strip of steel. Steel hollow sections, large pipes used as transmission fluid, such as oil, natural gas, coal gas, water, some solid material piping and so on. Steel and solid steel round bar compared to resistance to bending and torsional strength is the same as light in weight, is a kind of economic section steel, widely used in the manufacture of structural components and mechanical parts, such as drill, propeller shafts, bike racks and construction steel scaffolding used in the construction. Steel pipe manufacturing ring parts can increase material utilization, simplifying the manufacturing process, saving material and processing time, such as Jack and bearing rings, has been widely used to make. Steel or a variety of indispensable materials of conventional arms, the barrel, the barrel must steel pipe manufacturing. Pipe cross sectional area can be divided into different shapes round tube and tube. Because the perimeter under equal conditions, the largest, with circular tube can deliver more fluid. In addition, the ring cross-section when subjected to internal or external pressure, force more evenly, so most of the steel pipe is the pipe.
However, the tube has certain limitations, such as under plane bending conditions, the tube is not square and rectangular
