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Sep 11, 2025

ASTM A312 TP321 Stainless Steel Seamless Pickled Annealed Tube

 
ASTM A312 TP321 stainless steel seamless pickled annealed tube
 

Gnee Steel

 

ASTM A312 TP321 stainless steel seamless pickled annealed tube

321 stainless steel seamless pickled and annealed tubes offer excellent corrosion resistance, particularly intergranular corrosion, due to the stabilization effect of the titanium alloy. They also exhibit good oxidation resistance at high temperatures, making them ideal for applications such as furnace components, heat exchangers, and aircraft exhaust systems. After manufacturing, the tubes undergo a pickling process to remove thermal oxide scale and are then softened by annealing, resulting in an excellent surface finish, enhanced corrosion resistance, and improved mechanical properties.

ASTM A312 TP321 stainless steel seamless pickled annealed tube

Gnee Steel

 

What is 321 grade stainless steel pipe made of?

321 grade stainless steel pipe is a titanium-stabilized austenitic steel. Titanium stabilization imparts good corrosion resistance to the material. However, the presence of titanium also limits its use as a welding material due to its poor migration properties during arc welding.

21 grade stainless steel pipe

ASTM A312 321 seamless stainless steel pipe is a high-performance, versatile pipe used in a wide range of industries. Available in a wide range of sizes, with outer diameters typically ranging from 6 mm to several hundred millimeters, and a wide range of wall thicknesses. Its production adheres to the ASTM A312 standard, ensuring product quality and performance meet international standards.

 

ASTM A312 321 seamless stainless steel pipe is primarily composed of chromium (Cr), nickel (Ni), and a small amount of titanium (Ti). The addition of these elements imparts unique properties to the pipe:
Chromium (Cr): Significantly improves the material's corrosion resistance, effectively resisting attack by various corrosive media.
Nickel (Ni): Enhances the material's toughness and resistance to high-temperature oxidation.
Titanium (Ti): As a stabilizing element, it effectively prevents the precipitation of chromium carbides during welding, thereby preventing intergranular corrosion in the weld and heat-affected zone, and ensuring the overall stability of the pipe's performance.

 

321 stainless steel seamless pickled annealed tube Specifications

Outer Diameter 1/4" - 24"
Wall Thickness Sch5s - XXS
NPS 1/4"-18"
Schedule 10/10S,40/40S,80/80S
Material Grade TP304L,TP316L,TP317L,TP321/321H,TP310S,TP316Ti,TP347H
Standard ASTM A321
Application Used in Fluid and Gas Transport, Structure and Machining, etc
Process Method Cold Drawn/Cold Rolled
Quality Requirement 100% inspection for every pipes, including but not limited to dimensional inspection, chemical components, mechanical property and ET performed.

 

ASTM A312 321 Stainless Steel Seamless Pipe Chemical Composition

SS GRADE

UNS.

ASTM A312 CHEMICAL COMPOSITION % MAXIMUM
C MN P S SI CR NI Ti
TP321 S32100 0.08 2.00 0.045 0.030 1.00 17.0-19.0 9.0-12.0

5 × (C+N) min,

0.70 max

 

ASTM A312 TP321 stainless steel seamless pipe maintains excellent corrosion resistance in various harsh environments such as high temperature and high pressure, including corrosive media such as acids, alkalis, and salts. The high nickel content enables TP321 stainless steel seamless pipe to maintain high strength and toughness under high temperature conditions. At the same time, the addition of titanium makes TP321 stainless steel seamless pipe less prone to cracking and embrittlement during welding, making it easy to process and weld, ensuring the quality and reliability of the welded joints. The austenitic structure gives the pipe excellent mechanical properties, with sufficient strength to withstand working pressure while also having good toughness.

 

ASTM A312 TP321 Stainless Steel Seamless Pipe Mechanical Properties

SS GRADE HEAT TREATMENT Tensile Strength, min ksi [MPa] Yield Strength, min ksi [MPa]
Cold Finished Hot Finished
TP321

2000 °F [1100 °C]

1925 °F [1050 °C]

75 [515] 30 [205]

 

ASTM A312 TP321 Seamless Stainless Steel Pipe Applications

Oil and Gas Industry: ASTM A312 TP 321 seamless stainless steel pipe is becoming an ideal choice for oil and gas transmission pipelines, refinery process piping, and offshore platforms.

Chemical Industry: TP321 seamless stainless steel pipe is widely used in the manufacture of chemical equipment, piping systems, and storage tanks to meet high corrosion resistance requirements.

Nuclear Energy: TP321 seamless stainless steel pipe has become a key material for primary and secondary systems in nuclear power plants.

Aerospace: TP321 seamless stainless steel pipe is used in the manufacture of critical components such as aircraft engine parts, fuel systems, and heat exchangers.

Food Processing: Due to its smooth interior surface, non-toxicity, and easy cleaning, it has become the material of choice for food processing equipment, piping, and containers.

 

Gnee Steel

 

About Gnee Steel

Gnee Steel specializes in the production and sale of a wide range of stainless steel products, including 304, 316, 321, 904, 904L, 2205 Duplex, 2205 Duplex, and 316L stainless steel. Gnee Steel's products are widely used in the kitchen, aerospace, chemical, power, automotive, and nuclear energy sectors. We also provide custom stainless steel solutions tailored to customer needs. For stainless steel pricing or custom alloy solutions, please email ru@gneesteelgroup.com for a quote.

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