ASTM A240 alloy 317L (UNS S31703, 1.4438) is a low carbon version of austenitic stainless steel 317, which is designed to be used in applications where high temperature corrosion resistance is required. This AISI 317L has excellent resistance to strong reducing environments, such as sulfuric acid, and has good resistance to high temperature oxidation.
Introduction ASTM A240 UNS S31703 Plate Sheet Strip
The chemical composition of ASTM A240 UNS S31703 consists of chromium, nickel, molybdenum, and a low amount of carbon. The addition of molybdenum increases the corrosion resistance of the alloy 317 in acidic environments. The low carbon content prevents carbide precipitation, which can cause intergranular corrosion in stainless steel.
Alloy 317L UNS S31703 is an excellent choice for chemical and petrochemical processing equipment, pulp and paper processing equipment, and flue gas desulfurization equipment. It is also suitable for use in food and pharmaceutical processing equipment due to its low carbon content and excellent corrosion resistance.
DIN 1.4438 Alloy 317L is available in various forms, such as plate, sheet, coil, and strip, and can be supplied in annealed or cold worked conditions. The AISI 317 is also weldable and can be formed using standard fabrication techniques.
ASTM A240 UNS S31703 plate is the specification for this alloy, which covers sheet, plate, and strip made from the same material. This specification outlines the chemical and mechanical properties of the alloy, as well as the methods for testing the performance of the material.
1. Chemical Composition Analysis:
Method: X-ray Fluorescence (XRF) or Optical Emission Spectrometry (OES)
2. Mechanical Properties Testing:
Methods: Tensile testing, hardness testing, impact testing
3. Corrosion Resistance Testing:
Methods: Salt spray testing, corrosion coupon testing, electrochemical corrosion testing
Chemical Composition Analysis (Weight %)
| Element | Chromium (Cr) | Nickel (Ni) | Molybdenum (Mo) | Carbon (C) | Manganese (Mn) | Phosphorus (P) | Sulfur (S) | Silicon (Si) |
| UNS S31703 | 18.0 - 20.0% | 11.0 - 15.0% | 3.0 - 4.0% | Max 0.030% | Max 2.00% | Max 0.045% | Max 0.030% | Max 0.75% |
Primary Applications of ASTM A240 317L Plates
Thanks to its enhanced thermal thresholds and chemical stability, EN 1.4438 stainless steel sheets are utilized in extreme severe-service industrial installations:
Flue Gas Desulfurization (FGD) Systems: Absorber towers, scrubbers, and duct liners exposed to highly corrosive sulfur dioxide (SO_2) emissions.
Chemical & Petrochemical Processing: Heat exchangers, distillation columns, reactor vessels, and piping networks handling organic, fatty, and phosphoric acids.
Pulp and Paper Manufacturing: Bleaching vats, digesters, and stock washers utilizing aggressive chlorine compounds.
Food & Pharmaceutical Machinery: Equipment operating in high-chloride sanitizing zones that demand ultra-low intergranular corrosion risks.
Marine & Offshore Infrastructure: Heavy industrial plate components exposed to continuous seawater splash zones and salt fog.
Comprehensive Value-Added Processing & Inspection Services
At HT Pipeline, we don't just supply raw steel-we offer full-scale custom fabrication, finishing, and processing services at our high-tech facility:
Precision Cutting Capabilities: Plasma arc cutting, laser profile cutting, and waterjet cutting tailored to your exact CAD construction drawings.
Surface Finishes: Available in No.1 (hot rolled, annealed, and descaled), 2B (cold rolled), and polished architectural or sanitary finishes.
Advanced Testing Protocols: Comprehensive testing via X-ray Fluorescence (XRF), Optical Emission Spectrometry (OES) chemical analysis, hydrostatic testing, and ultrasonic non-destructive testing (NDT).
In summary, ASTM A240 grade 317L (UNS S31703, 1.4438) is a low carbon version of austenitic stainless steel, designed to be used in applications where high temperature corrosion resistance is required. This ASME SA240 gr 317l sheet has excellent resistance to strong reducing environments, such as sulfuric acid, and has good resistance to high temperature oxidation.
It is an excellent choice for chemical and petrochemical processing equipment, pulp and paper processing equipment, and flue gas desulfurization equipment. It is also suitable for use in food and pharmaceutical processing equipment due to its low carbon content and excellent corrosion resistance.
