AM 350 Plates | UNS S35000 High-Strength Stainless Plates for Chemical, Oil & Gas, Marine, Pharma & Power
Table of Contents:
A refinery–power cogeneration site on the coast thought it had solved its fatigue and corrosion issues by switching from standard 410/420 stainless and quenched‑and‑tempered carbon steels to 316L plate in critical clamp rings, compressor shrouds and high‑load brackets, but vibration, thermal cycling and occasional chloride contamination kept producing cracks and unplanned outages in rotating equipment and hot gas housings. When the reliability and procurement teams redesigned these components in AM 350 Plates (UNS S35000), a precipitation‑hardening chromium–nickel–molybdenum stainless steel, they moved to a material whose annealed condition already delivers tensile strengths up to about 1105–1380 MPa, yield strengths around 415–585 MPa and a modulus of elasticity of 190–210 GPa, and whose cold‑worked plus aged conditions can exceed 1275–1380 MPa tensile and 1000–1035 MPa yield strength while maintaining usable ductility in service.
AM 350 (also designated Alloy 350 or AISI 633) is a precipitation‑hardening stainless steel that can develop a duplex austenitic–martensitic structure and combines high strength with good corrosion and oxidation resistance. It contains about 16–17% chromium, 4–5% nickel and 2.5–3.25% molybdenum with controlled carbon, manganese, silicon and nitrogen, and can be strengthened by either martensitic transformation plus precipitation hardening or by work hardening, giving designers a wide range of property combinations for plate, sheet and strip.
For procurement heads, equipment and corrosion engineers, fabricators, OEM manufacturers and hardware or industrial supply stores in chemical, oil & gas, marine, pharma and power‑generation sectors, AM 350 plates answer a specific problem: the need for significantly higher strength and fatigue resistance than 304/316 or 904L can offer, but without the brittle behaviour or limited weldability of many conventional martensitic steels. Data compiled for UNS S35000 show that precipitation‑hardened sheet and strip can achieve room‑temperature tensile strengths of around 185–200 ksi (≈1275–1380 MPa) and yield strengths of around 145–150 ksi (≈1000–1035 MPa) while maintaining enough elongation for forming and in‑service strain, and corrosion investigations report that AM 350 has pitting resistance numbers higher than some other precipitation‑hardening stainless steels and that suitably passivated AM 350 can operate in chloride and sulfuric‑acid environments with corrosion current densities on the order of 10⁻³ to 10⁻⁵ mA/cm².
High-quality AM 350 Plates ready for industrial use.
Specification Overview
| Supplier & Role | Aurico Alloys LLP – AM 350 Plates supplier, stockist, exporter in India to abroad |
|---|---|
| Alloy Description | Precipitation‑hardening chromium–nickel–molybdenum stainless steel which can be strengthened by martensitic transformation and aging, offering high strength with good corrosion resistance |
| UNS / AISI | UNS S35000, AISI 633, commonly referenced as AM 350 or Alloy 350 |
| Main Plate Standards | ASTM A693 Grade 633 (plate, sheet, strip), ASME SA‑693 Grade 633 and AMS 5548 / related AMS specifications for sheet and strip |
| Thickness Range | 4.75 mm – 150 mm |
| Microstructure | Controlled austenite–martensite mixture with 5–10% delta ferrite in some conditions, tailored via heat treatment for strength and toughness |
UNS & Equivalent Grades
| Property | Value |
|---|---|
| UNS number | S35000 |
| Werkstoff / EN number | — |
| EN designation | — |
| Density | 7.94 g/cm3 |
| Melting range | 1370-1400 °C |
Identifiers and physical constants for AM 350. A dash means no such designation is published for this grade.
Stock & Product Availability
As an AM 350 Plates stockist, Aurico Alloys LLP can provide plate, sheet and strip thicknesses suitable for clamp rings, compressor and turbine shrouds, pump components, valve parts, brackets and structural plates used in chemical, oil & gas, marine, pharma and power‑generation equipment, within the thickness ranges cited for ASTM A693 Grade 633 products. One producer notes cold‑rolled sheet thicknesses of around 2–5 mm at widths near 1000 mm and hot‑rolled plate thicknesses from about 6–80 mm at widths 210–610 mm, with length supplied to order, which gives fabricators and OEMs flexibility in nesting and yield.
Chemical Composition
| Element | Min (%) | Max (%) |
|---|---|---|
| Iron (Fe) | — | Balance |
| Carbon (C) | 0.07 | 0.11 |
| Chromium (Cr) | 16.0 | 17.0 |
| Nickel (Ni) | 4.0 | 5.0 |
| Molybdenum (Mo) | 2.5 | 3.25 |
| Nitrogen (N) | 0.07 | 0.13 |
| Manganese (Mn) | 0.5 | 1.25 |
| Silicon (Si) | — | 0.5 |
| Phosphorus (P) | — | 0.04 |
| Sulfur (S) | — | 0.03 |
Composition limits for AM 350. These are specification limits for the grade, not measured values for a lot; the mill test certificate supplied with your order states the actual analysis.
Mechanical & Physical Properties
| Property (Typical) | Value – AM 350 |
|---|---|
| Tensile Strength (annealed / solution-treated) | ≈1105 MPa reported for some plate products; datasheets cap annealed strip at about 1380 MPa |
| Yield Strength (0.2% offset, annealed) | ≈415–585 MPa depending on product and condition |
| Tensile Strength after aging (e.g., 850–1000 °F) | ≥1275–1380 MPa with yield strengths around 1000–1035 MPa in aged strip |
| Elongation (room temperature) | ≥8–12% depending on gauge and condition for sheet/strip; higher values reported for annealed states |
| Elastic Modulus | ≈190–210 GPa (27.5–30.4 × 10³ ksi) |
| Hardness | ≤30 HRC (Re 30 max) in typical specifications for strip; higher after full aging |
| Corrosion Behaviour | Laboratory studies show AM 350 exhibits pitting corrosion in NaCl and H₂SO₄ but with PREN values and performance superior to some PH stainless steels, with corrosion current densities on the order of 10⁻³–10⁻⁵ mA/cm² under tested passivation conditions. |
Applications & Benefits
- Chemical & Oil & Gas: AM 350 plates are used in high‑strength clamps, supports, pump and valve components, compressor internals and fasteners where precipitation‑hardened strength reduces section thickness and weight while still providing corrosion resistance in mildly corrosive acids and chloride‑bearing environments.
- Marine & Power: In marine and power‑generation equipment, UNS S35000 is cited for high‑strength shafts, couplings and structural components that must withstand cyclic stresses, vibration and moderate corrosion, providing better strength than 304/316 while avoiding some brittleness issues of plain martensitic steels.
- Pharma & OEM: OEMs in pharma and high‑purity service use AM 350 for spring components, diaphragms and high‑strength mechanical parts around process equipment where cleanability, toughness and fatigue resistance matter more than extreme acid resistance, complementing more corrosion‑focused alloys in wetted zones.
FAQ & Search Trends
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Domestic Supply Network
We deliver across India from our Mumbai stockyard. See every city we supply on our supply locations page.
Conclusion
AM 350 Plates from Aurico Alloys LLP, supplied to UNS S35000 chemistry limits and ASTM A693 Grade 633 mechanical requirements, give chemical, oil & gas, marine, pharma and power‑generation users a precipitation‑hardening stainless option that combines very high strength, good corrosion resistance and weldability for critical brackets, clamps, shrouds and structural components are your most demanding high‑load, vibration‑prone and chloride‑exposed assets still relying on lower‑strength steels instead of optimised AM 350 plates?