In the hot-rolled seamless pipe , hot rolling is related to cold rolling, cold rolling is rolling performed below the recrystallization temperature, and hot rolling is rolling performed at a temperature above the recrystallization temperature. According to different uses and materials, hot-rolled seamless pipe is divided into many types, such as alloy pipe, mainly used in petroleum, smelting, chemical and other fields; high-pressure boiler pipe, mainly used for heat pipe, steam pipe and other high-pressure boiler related equipment Pipeline manufacturing; high-pressure chemical fertilizer pipes; pipes used in ultra-low temperature (-40 degrees) or ultra-high temperature (400 degrees) working environments and high pressure environments. Hot-rolled seamless pipes have a wide variety of classifications, and the corresponding uses of each small classification are different. Therefore, each type also has different specifications and follows different implementation standards. Below we list the execution standards and specifications of the ten most commonly used steel pipes for everyone.
Hot rolled seamless tube classification
Hot rolled seamless tube
Hot-rolled seamless steel tubes are divided into general steel tubes, low- and medium-pressure boiler steel tubes, high-pressure boiler tubes, alloy steel tubes, stainless steel tubes, petroleum cracking tubes, geological steel tubes, and other steel tubes.
Cold rolled (dial) seamless steel pipe
In addition to general steel pipes, low and medium pressure boiler steel pipes, high pressure boiler steel pipes, alloy steel pipes, stainless steel pipes, oil cracking pipes, and other steel pipes, it also includes carbon thin-wall steel pipes, alloy thin-wall steel pipes, stainless thin-wall steel pipes, and special-shaped steel pipes. . The outer diameter of hot-rolled seamless pipe is generally greater than 32mm, and the wall thickness is 2.5-75mm. The outer diameter of cold-rolled seamless steel pipe can reach 6mm, the wall thickness can reach 0.25mm, the outer diameter of thin-wall pipe can reach 5mm, and the wall thickness is less than 0.25mm. Cold rolling has higher dimensional accuracy than hot rolling.
Hot rolled seamless tube features
advantage
It can destroy the ingot casting structure, refine the grain of the steel, and eliminate the defects of the microstructure, so that the steel structure is dense and the mechanical properties are improved. This improvement is mainly reflected in the rolling direction, so that the steel is no longer isotropic; to a certain extent, the bubbles, cracks and looseness formed during casting can also be welded under high temperature and pressure.
Shortcomings
After hot-rolling, the non-metallic inclusions (mainly sulfides and oxides, and silicates) inside the steel are pressed into thin sheets and a delamination (sandwich) phenomenon occurs. Stratification greatly degrades the properties of the steel in the thickness direction, and it is possible that interlayer tearing occurs when the weld seam shrinks. The local strain induced by weld shrinkage often reaches several times the strain at yield point, much larger than the strain caused by load; 2. Residual stress caused by uneven cooling. Residual stress is the stress of internal self-phase equilibrium under no external force. Hot rolled steel of various sections has such residual stress. The larger the section size of general steel, the greater the residual stress. Although the residual stress is self-balanced, it still has some influence on the performance of steel components under external forces. Such as deformation, stability, anti-fatigue and other aspects may have an adverse effect. 3. Hot-rolled steel products have poor control over thickness and side width. We are familiar with thermal expansion and contraction, because at the beginning of hot rolling even if the length, thickness are up to standard, and finally there will be a certain negative difference after cooling, the wider the width of the negative difference, the thicker the more obvious the performance. So for large steels, there is no way to be too precise about the width, thickness, length, angle, and edges of the steel.
Hot Rolled Seamless Pipe Execution Standards and Specifications
Alloy tube
Implementation standards: GB5310-2008, GB6479-2000, GB9948-2006, DIN17175-79, ASTMSA335, ASTMSA213, JISG3467-88, JISG3458-88
Specifications: ∮8-1240*1-200
Stainless steel tube
Executive Standard: GB/T14975-2002, GB/T14976-2002, GB13296-2007, ASTMA213, ASTMA269, ASTMA312, JISG3459, DIN17458
Specifications: ∮6-630*0.5-60
3. Low temperature tube
Executive Standard: GB/T18984-2003, ASTMA333
Specifications: ∮8-1240*1-200
4. High pressure boiler tube
Executive standard: GB5310-1995, ASTMSA106, ASTMSA210, DIN17175-79, GB6479-2000
Specifications: ∮8-1240*1-200
5. Petroleum Cracking Tube
Executive Standard: GB9948-2013
Specifications: ∮8-630*1-60
6. Low and medium pressure boiler tubes
Executive Standard: GB3087-2008
Specifications: ∮8-1240*1-200
7. Delivery fluid tube
Executive Standards: GB/T8163-2008, ASTMA106, ASTMA53
Specifications: ∮8-1240*1-200
8. General structure
Executive Standard: GB/T8162-2008, GB/T17396-1998, ASTMA53
Specifications: ∮8-1240*1-200
9. Oil casing
Executive Standard: APISPEC5CT, ISO11960
Specifications: ∮60.23-508.00*4.24-16.13
10. Straight seam steel pipe
Implementation standards: GB/T13793-1992, GB3091-2001
Specifications: ∮32-630*1-30
Hot rolled seamless tube preparation
Generally used seamless steel pipe: is used 10,20,30,35,45 and other high-quality carbon steel 16Mn, 5MnV such as low-alloy structural steel or 40Cr, 30CrMnSi, 45Mn2, 40MnB alloy steel such as hot or cold rolled into. 10,20 and other seamless tubes made of low carbon steel are mainly used for fluid transportation pipelines. 45, 40Cr and other medium carbon steel seamless tubes are used to make mechanical parts, such as parts for cars and tractors. Generally used seamless steel pipe to ensure strength and flattening test. The hot-rolled steel pipe is delivered in a hot-rolled state or a heat-treated state; the cold-rolled steel is delivered in a heat-treated state.
1. Hot rolling (extrusion seamless steel pipe): round billet → heating → perforation → three-roller oblique rolling, continuous rolling or extrusion → de-spooling → sizing (or reducing) → cooling → straightening → hydrostatic test (or Flaw Detection) → Mark → Inbound
2. Cold drawn (rolled) seamless steel pipe: round billet → heating → punching → start → annealing → pickling → oil coating (copper plating) → multi-pass cold drawing (cold rolling) → blank tube → heat treatment → straightening →Hydrostatic Test (Flaw Detection) → Marking → Storage
Calculation formula
(OD - wall thickness) * Wall thickness * 0.02466 = kg/meter (weight per meter)
Editor's summary: Hot-rolled seamless pipes are mostly used for fluid transportation in large-scale construction processes, which are beneficial to petroleum smelting plants, geological exploration, gas hydraulics, and transportation of corrosive materials. Therefore, the quality requirements for pipes are very high, and they are required to be The material has high corrosion resistance and pressure resistance, and the production process needs precise and accurate, strictly complete and seamless, to prevent leakage of the transport liquid. Because there are many types of hot-rolled seamless pipes, when users use them, they need to choose the most suitable pipe according to their actual construction needs.
Steel Tube Metal Tube Steel Imported Steel Hot Rolled Seamless Tube
Ultra strong wear resistance property, able to provide effectively protection for engines that adopting exhaust gas recirculation technology;
.Ultra strong acid neutralization property, prevent engine parts from corrosion and corrosion wear;
.Ultra strong cleaning and dispersing ability, effectively control Engine Oil sludge and piston deposits;
.Stable oil film, maintain strong power;
.Excellent high temperature oxidation resistance property, effectively prolong oil change cycle;
.Meet European IV emission regulation requirements, applicable to fuels with different sulfur content.
2. Scope of application:
Applicable to various engine lubrication systems of construction machineries, like bulldozer ,roller, excavator,loader,pipe hoist, grader,crane,paver,push rake machine ,forklift and large transport vehicles.
3.Qality Grade: CI-4
4.Viscosity Grade:5W-30 10W-30 10W-40 15W-40 20W-50
5.Packing Specification: 4L 16L 18L
Excavator Spare Parts ,Bulldozer Spare Parts,Construction Machinery Oil,Pipelayer Spare Parts, Loader Spare Parts ,Construction Machinery Attachment.
Hydraulic Oil
Hydraulic Oil, Anti-Wear Hydraulic Oil, High Pressure Hydraulic Oil, Hydraulic Transmission Oil,Anti-wear Engine Oil
Jining Changsong Construction Machinery Co., Ltd. , https://www.jncsmachinery.com