347H stainless steel pipe vs.316L stainless steel pipe

When selecting stainless steel pipes for high-temperature or corrosive environments, 347H and 316L are often compared by engineers and procurement professionals. While both grades offer good corrosion resistance, their chemical makeup and thermal stability differ significantly-impacting long-term performance and cost.

In this article, we'll compare 347H stainless steel pipe and 316L stainless steel pipe in terms of chemical composition, mechanical properties, temperature resistance, corrosion resistance, and applications, helping you choose the right material for your project.

 

316L stainless steel pipe Standards

Grade	Standards Supported
316L	ASTM A312 / A269 / A213 / EN 10216-5
347H	ASTM A312 / A213 / A358 / EN 10216-5

Both grades are available in seamless and welded forms, and GNEE supplies them with MTC 3.1/3.2, third-party inspection, and custom lengths on request.

 

347H vs. 316L Stainless Steel Pipe：Chemical Composition

Element	316L (% by weight)	347H (% by weight)
Carbon (C)	≤ 0.03	0.04 – 0.10 (Higher for creep strength)
Chromium (Cr)	16.0 – 18.0	17.0 – 19.0
Nickel (Ni)	10.0 – 14.0	9.0 – 13.0
Molybdenum (Mo)	2.0 – 3.0	- (Not present)
Manganese (Mn)	≤ 2.00	≤ 2.00
Silicon (Si)	≤ 1.00	≤ 1.00
Phosphorus (P)	≤ 0.045	≤ 0.040
Sulfur (S)	≤ 0.030	≤ 0.030
Nitrogen (N)	≤ 0.10	≤ 0.10

 

The molybdenum content (2-3%) of 316L stainless steel pipe makes its pitting resistance equivalent (PREN) reach 26, which is significantly higher than 18 of 347H, making it more suitable for marine engineering (such as seawater desalination equipment) and chemical environments containing Cl⁻. 347H performs well in molten salt at 450-565℃ and is used in storage tanks of solar thermal power plants; 316L has insufficient corrosion resistance because molybdenum easily reacts with molten salt.

 

Mechanical Properties

Property	316L	347H
Tensile Strength	≥ 485 MPa	≥ 515 MPa
Yield Strength	≥ 170 MPa	≥ 205 MPa
Elongation (%)	≥ 40	≥ 35
Hardness (HRB)	≤ 95	≤ 95

 

The tensile strength of 347H stainless steel high-temperature pipe is ≥515MPa (ASTM A213), the allowable stress is still above 100MPa at 600℃, the maximum oxidation resistance temperature is 850℃ (non-pressure-bearing parts), and it is suitable for high-temperature superheaters of supercritical power station boilers.
The tensile strength of 316L stainless steel heat-resistant pipe is ≥520MPa (ASTM A312), but the high-temperature strength decreases rapidly, and the maximum operating temperature is about 590℃, which is mainly used for normal temperature or medium temperature corrosion-resistant structures.

 

Cold-processed 347H stainless steel pipes have a significant hardening effect and require intermediate annealing (850-900℃); 316L has better processing performance and is suitable for complex forming (such as corrugated pipes).
347H stainless steel pipes are recommended to use niobium-containing welding wires (such as ER347). During TIG welding, the heat input must be controlled to ≤1.5kJ/mm and the interlayer temperature must be ≤150℃ to avoid NbC precipitation and embrittlement. 316L uses molybdenum-containing welding wires (such as ER316L) with good weldability. Argon-free flux-cored welding wires (such as TGF-316L) can be used to improve on-site efficiency without strict preheating.

 

 

The price of 347H seamless pipe is about 28,000-32,000 yuan/ton, 10-15% higher than 316L. The price of 316L with the same specifications is about 25,000-28,000 yuan/ton, with obvious cost-effectiveness.

 

Scenarios for choosing 347H:
High temperature environment (>550℃): such as power plant boilers, solar thermal power generation.
Parts that cannot be heat treated after welding: rely on niobium stabilization to avoid intergranular corrosion.
Sulfide corrosion resistance: such as refinery hydrogenation units.
Scenario for choosing 316L:

Chloride environment: such as marine engineering, chemical equipment.
Frequent welding and no post-processing conditions: ultra-low carbon characteristics reduce sensitization risks.
General corrosion-resistant structures that are cost-sensitive: such as food machinery and medical equipment.

 

Why Choose GNEE for 316L Stainless Steel Pipe?
✅ Full Material Traceability: Mill test certificates (EN 10204 3.1 / 3.2) provided with every order
✅ Third-Party Inspection Support: SGS, BV, TÜV, ABS, LR certification available upon request
✅ Export-Grade Packaging: Wooden cases with waterproof film, capped pipe ends, seaworthy protection
✅ Quick Lead Time: 7–15 working days for stock items; flexible scheduling for bulk orders

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