UNS N08904|1.4539|TP904L Seamless Stainless Steel Pipe

Seamless Stainless Steel TP904L Pipes (UNS N08904 / W.Nr. 1.4539) are premium super-austenitic solutions engineered for exceptional resistance to pitting, crevice corrosion, and stress corrosion cracking (SCC) in aggressive media. As a premier manufacturer based in Wenzhou, China, XinZhe produces high-integrity seamless piping that strictly complies with ASTM B677, ASTM A312, and ASME SB677 international standards.

Distinguished by its high Nickel and Molybdenum content and the strategic addition of Copper (Cu), our 904L tubing offers superior resistance to strong reducing acids, particularly dilute sulfuric acid, across the entire concentration range. These pipes are indispensable for mission-critical applications in chemical reactors, seawater cooling systems, and pharmaceutical processing. Through advanced cold-drawing and precise solution annealing, XinZhe ensures every pipe maintains a uniform microstructure and optimized mechanical strength for the most demanding industrial environments.

PREN≥35,higher than TP316L PREN≥24

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What Is TP904L Seamless Pipe?

Seamless Stainless Steel TP904L Pipe | UNS N08904 Super Austenitic Pipe for Severe Corrosion Environments

1. What is TP904L Seamless Stainless Steel Pipe?

Product Overview

TP904L seamless stainless steel pipe (UNS N08904 / EN 1.4539) is a high-performance super-austenitic stainless steel designed for the most aggressive corrosive environments, especially where standard 316L and 317L grades fail.

Manufactured using a seamless process (hot extrusion / hot piercing + cold drawing or cold rolling), TP904L pipes feature:

Uniform microstructure
No weld seam risk
Superior pressure resistance
Enhanced reliability in critical applications

The alloy is characterized by:

Very low carbon content (≤0.020%) to prevent sensitization
High Nickel (23–28%) for corrosion and SCC resistance
High Molybdenum (4.0–5.0%) for pitting resistance
Copper (1.0–2.0%) for excellent resistance to reducing acids

Additional Information

This combination makes TP904L one of the most corrosion-resistant stainless steels available.

2. Key Features and Technical Advantages

Outstanding Resistance to Strong Acids

TP904L exhibits exceptional resistance to reducing acids, especially:

Sulfuric Acid (H₂SO₄)
Phosphoric Acid (H₃PO₄)
Acetic Acid

This makes it ideal for chemical processing and acid handling systems.

Superior Pitting & Crevice Corrosion Resistance

With a high PREN (Pitting Resistance Equivalent Number) due to Mo and Ni content, TP904L performs excellently in:

Chloride-rich environments
Seawater
Offshore applications

Excellent Stress Corrosion Cracking (SCC) Resistance

The high nickel content significantly improves resistance to chloride-induced SCC, making it suitable for:

Marine environments
Chemical plants
Heat exchanger systems

Fully Austenitic & Non-Magnetic Structure

TP904L maintains:

Stable austenitic microstructure
Very low magnetic permeability
Excellent performance after cold working

High Mechanical Strength & Pressure Integrity

Manufactured according to ASTM A312 / ASTM A269 / EN 10216-5, ensuring:

Reliable performance under high pressure
Consistent wall thickness
Safe operation in critical systems

3. Chemical Composition (UNS N08904 / TP904L)

Key insight: The synergy of Mo + Cu + high Ni is what gives TP904L its superior acid resistance and corrosion performance.

Table 2: Typical Mechanical Properties of Stainless Steel 904L

Stainless Steel 904L is specifically designed to maintain its strength and shape in high-stress, corrosive environments.

Table 3: Typical Physical Properties of Stainless Steel 904L

These physical properties highlight the material's ability to perform reliably under a wide range of conditions.

Table 4: The Standard of Stainless Steel Seamless Pipe Size Tolerance Size Chart :

6. Typical Industrial Applications

TP904L seamless stainless steel pipes are widely used in industries requiring extreme corrosion resistance:

Chemical & Petrochemical Industry Sulfuric acid, phosphoric acid production equipment
Oil & Gas Offshore Systems Seawater cooling systems, subsea pipelines, scrubbers
Pulp & Paper Industry Bleaching equipment and corrosive process lines
Pharmaceutical & Food Processing High-purity and CIP/SIP systems
Hydrometallurgy Copper, nickel, and zinc extraction processes

7. Quality Assurance & Inspection

Each TP904L pipe undergoes strict quality control to ensure full compliance with international standards:

Testing & Inspection

100% Positive Material Identification (PMI)
Non-Destructive Testing (NDT):
Ultrasonic Testing (UT)
Eddy Current Testing (ET)
Hydrostatic Testing
Corrosion Testing:
ASTM A262 (Intergranular Corrosion)
Pitting resistance tests

Certification & Traceability

EN 10204 3.1 / 3.2 Material Test Certificates (MTC)
Heat treatment records
Full traceability from raw material to finished product
Third-party inspection: SGS, BV, TUV, DNV, ABS

Tensile Strength	Yield Strength	Elongation	Hardness
≥ 490 MPa	≥ 220 MPa	≥ 35%	≤ 192 HBW

Density	Melting Point	Thermal Expansion	Thermal Conductivity	Modulus of Elasticity	Electrical Resistivity
8.0 g/cm³	1300 - 1390 °C approx.	16.5 µm/m·°C (20-100°C)	13.9 W/m·K (20°C)	195 GPa	0.85 x 10⁻⁶ Ω·m (20°C)

Chemical Composition

Cr	Ni	P	S	Mo	Cu	Mn	Si	C
19.00 - 23.00	23.00 - 28.00	≤ 0.040	≤ 0.030	4.00 - 5.00	1.00 - 2.00	≤ 2.00	≤ 1.00	≤ 0.02

Size Tolerance Chart

Standard	OD(D)	Tolerance （MM)		Thickness(S)	Tolerance(MM)	Length	Tolerance
	MM	Common	High	MM			MM
ASTM A312	D ≤48.3	+0.4/-0.8		10.3 ≤73	+20%-12.5%		+6.0/0
	48.3 ≤114.30	±0.8		88.9 ≤457.2,t/D ≤5%	+22.5%/-12.5%
	114.3 ≤219.1	+1.6/-0.8		88.9 ≤457.2,t/D >5%	+15%/-12.5%
	219.1 ≤457.2	+2.4/-0.8		D ≥508, t/D≤5%,SMLS	+22.5%/-12.5%
	457.2 ≤660.4	+3.2/-0.8		D ≥508, t/D>5%,SMLS	+15%/-12.5%
	660.4 ≤863.6	+4.0/-0.8		D ≥508, WELD	+17.5%/-12.5%
	863.6 ≤1219.2	+4.8/-0.8
JIS 3459 Hot-Finished Smls Pipe	D ＜50	±0.51		S ＜4	±0.5
	D ≥50	±1.0%		S ≥4	±12.5%
JIS 3459 Cold-Finished	D ＜30	±0.3		S ＜2	±0.2
	D ≥30	±1.0%		S ≥2	±10.0%
JIS G3463 Hot-Finished Smls Pipe	100	+0.4/-0.8		D ＜100， S	/	D	+7/0
				D ＜100， 2≤S	+40%/0	D	+10/0
				D ＜100， 2.4≤S	+35%/0
				D ＜100， 3.8≤S	+33%/0
				D ＜100， 4.6≤S	+28%/0	D	+13/0
	100 ≤D	+0.4/-1.2		D>100, S ＜2	/
	120 ≤D			D>100 ， 2≤S	/	D	+15/0
	160 ≤D	+0.4/-1.8		D>100 ， 2.4≤S	+35%/0
	200 ≤D	+0.4/-2.4		D>100 ， 3.8≤S	+33%/0	D>50,7	+10/0
				D>100 ， 4.6≤S	+28%/0
JIS G3463 Cold-finished		+0.4/-0.8		D	+0.4/0
	60 ≤D	±0.3		D ≥2.0	+20%/0	D>50,7	+13/0
	80 ≤D	±0.4		D ≥40	+22%/0
	100 ≤D	+0.4/-0.6
	120 ≤D	+0.4/-0.8				D>50,10M	+15/0
	160 ≤D	+0.4/-1.2
	200 ≤D	+0.4/-1.6
GB/T 14975 冷拔(扎)钢管	D	±0.3	±0.1	所有壁厚，普通级PA	+12.5%/-10%
	12.7		±0.15
	38.1	±0.4	±0.3
	88.9	±0.9%	±0.4
	139.7		±0.8	所有壁厚，高级PC	±10%
	203.2		±1.1
	219.1		±1.6
	D ≥323.9		±0.5%
GB/T 14976 冷拔(轧)钢管	6	±0.2	±0.15	S ≤3	±12%(10% /0 高级PC)
	10 ≤D	±0.2	±0.2
	30 ≤D	±0.2	±0.3	S>3	+12.5%/-10%(10%/0 高级PC)
	50 ≤D	0.85%	0.75%
	D>219	0.9%	0.8%	Smin, all	+22%/0(+20%/0 高级PC)

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Send your TP904L Seamless Pipe enquiry with grade, applicable ASTM/ASME standard and edition, OD × wall thickness, length, quantity, end finish, delivery destination and inspection documents — you will get a written quotation stating the specification and edition, delivery condition, documents included and lead time.

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