Welded pipes and tubes
1 ) Ferritic Stainless Steel :
Ferritic stainless steel is a type of chromium alloy that has ferritic structure at elevated and room temperature with body-centered cubic crystal structures. It has a chemical composition consisting of C≤0.02% and Cr 10.5%~32% and cannot be hardened by heat treatment. Ferritic stainless steel is used in comprehensive applications with excellent general properties, and is taken as a kind of primary nickel-saving stainless steels.
Standard：
ASTM A268 Standard Specification for Seamless and Welded Ferritic and Martensitic Stainless Steel Tubing for General Service
JIS G3463 Stainless Steel for Boiler and Heat Exchanger Tubes
GB/T 30065 Welded ferritic stainless steel tubes for feedwater heater
GB/T 30066 Welded ferritic stainless steel tubes for heat-exchanger and condenser
Performance：
A. Ferritic stainless steel magentic
B. Ferrtic stainless steel of the themal expansion rate is low ,close to ordinary carbon body
C. Ferrtic heat transfer rate is high ,1.3 to 1.6 times of austenitic stainless steel,even the heat conduction and can improve the efficiency of heat exchange
D. Containing stabilizing element Nb ferritic stainless steel ,have good creep resistnce
E. Ferritic austenitic stainless steel can be more easily than cutting and procssing
F. When cold deformation,ferritic stainless steel deformation recovery is smaller than austenitic stainless steel ,deep drawing forming performance is better than austenitic stainless steel
G. Ferritic stainless steel have high strength of yield
H. Ferritic stainless steel have good uniform corrosion resistance,resistance to pitting and crevice corrosion resistance
I . As cost performance ,ferritic stainless steel haven’t contains Ni,so the costes are relatively cheap ,and will not affect by price fluctuation of Ni .
2) Ultra-pure Ferritic Stainless Steel :
Utral-pure Ferritic is refers to the gap element such as carbon,nitrogen content of ferritic stainless steel wich are very low, C+N≤120ppm-400ppm(250ppm,150ppm)，at any temperature,its mircrostructure is ferritic structure,chromium content of 17%-30% and 0-4% molybdenum content of iron base chrome molybdenum alloy.
Specifications：
409L、444、436L and so on hyperpure ferritic stainless steel,
The current development of steel grades: exhaust system (409 l, 429, 436 l, 439 m, 441), decoration (439, 443), water system (444、445/445J1/445J2）/446
Features：
A, good resistance to stress corrosion, all kinds of partly corrosion resistance and good oxidation resistance medium uniform corrosion ability (including high temperature oxidizing)
B, low density, under the condition of the same weight, material can be saved 2.5%
C, heat conduction performance is good
D, small thermal expansion coefficient
E, the large modulus of elasticity
F, good processing performance
1. The cold hardening tend to be low, for larger cold deformation, generally without intermediate annealing
2. Easy to cold bending, stamping, beading, pressure testing, cold forging and cutting
3. Good deep drawing performance.
3) Austenitic Stainless Steel Weld Pipe/Tube
Austenitic stainless steel has austenite as its primary phase at both elevated and room temperature. A stable austenite structured steel contains about 18% Cr, 8% ~ 10% Ni and about 0.1% C. Chrome-nickel austenitic stainless steel including the most familiar stainless steel 18Cr-8Ni (TP304) and the series of high Cr-Ni steel developed by increase Cr, Ni contents and add Mo, Cu, Si, Nb, Ti and other elements. Austenitic stainless steel is characterized by non-magnetic, high plasticity and ductility but lower strength. It can be only strengthened via cold working (by adding S, Ca, Se, Te and etc, austenitic stainless steel can have excellent machinability).
Specifications：
ASTM A312 Standard Specification for Seamless, Welded, and Heavily Cold Worked Austenitic Stainless Steel Pipes
ASTM A790 Standard Specification for Seamless and Welded Ferritic/Austenitic Stainless Steel Pipe
ASME SA213 Seamless Ferrite and Austenitic Alloy Steel Pipe for Boiler, Superheater and Heat Exchanger
ASME SA249 Standard Specification for Welded Austenitic Steel Boiler, Superheater, Heat-Exchanger, and Condenser Tubes
ASME SA789 Standard Specification for Welded Austenitic Steel Boiler, Superheater, Heat-Exchanger, and Condenser Tubes
GB/T14976-2002 Stainless steel seamless tubes for fluid transport
GB/T12771-2008 Stainless steel welded tubes for fluid transport
Features：
- Excellent corrosion resistance
2.Good for cold working or hot working
3.High plasticity and ductility
4.Optimum general performance
5.A wide range of applications
4) Super duplex stainless steel weld tubes/pipes
Specifications：
ASTM A249 / A249M Standard Specification for Welded Austenitic Steel Boiler, Superheater,
Heat-Exchanger, and Condenser Tubes
ASTM A269 : Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubing for General Service
ASTM A312 / A312M : Standard Specification for Seamless, Welded, and Heavily Cold Worked
Austenitic Stainless Steel Pipes
ASTM A358/A358M: Standard Specification for Electric-Fusion-Welded Austenitic
ASTM A778 : Standard Specification for Welded, Unannealed Austenitic Stainless
Steel Tubular Products
ASTM A789 / A789M : Standard Specification for Seamless and Welded Ferritic Austenitic Stainless Steel Tubing for General Service
ASTM A790 / A790M: Standard Specification for Seamless and Welded Ferritic Austenitic Stainless Steel Pipe
We also supply products with BS, JIS , DIN , EN , GOST.
Features：
1.Superior resistance to general and local corrosion, especially to stress corrosion, pitting corrosion, crevice corrosion, corrosion fatigue and abrasion & corrosion.
2.Good weldability
3.Good mechanical properties
4.Excellent intergranular corrosion resistance
5.High cost-effectiveness, long life time
5) Nickel based alloy welded pipes and tubes
Specifications：
SB-468 Specification for welded UNS N08020,N08024,and N08026 alloy tubes
SB-515 Specification for welded UNS N08120,UNS N08800,UNS N08810,and UNS N08811 alloy tubes
SB-516 Specification for welded nickel-chromium-iron alloy UNS N6600,UNS N06603,UNS N06025,and UNS N06045 tubes.
SB-517 Specification for welded nickel-chromium-iron alloy UNS N6600,UNS N06603,UNS N06025,and UNS N06045 pipes.
SB-619 Specification for welded nickel and nickel-cobalt alloy pipe
SB-626 Specification for welded nickel and nickel-cobalt alloy tube
SB-674 Specification for UNS N08904,UNS N08925,and UNS N08926 welded tube
SB-704 Specification for welded UNS N06625,UNS N06219,and UNS N08825 alloy tubes