Super Stainless Steel

Category

  • Bar and Rod

  • Plate and Sheet

  • Strip

  • Pipe and Tube

  • Wire

  • Welding

  • Powder Material

  • Cast Products

  • Forged Products

  • Fittings

  • Fastening

    Forms & Sizes

    Round Bar:
    φ2–500 mm, 1–6 m length

    Flat/Square Bar:
    4–100 mm thickness/width

    Hex Bar:
    A/F 3–100 mm

    Hollow Bar:
    OD 20–300 mm

    Forms & Sizes

    Sheet:
    0.3–6 mm thickness

    Medium Plate:
    6–25 mm thickness

    Heavy Plate:
    25–100 mm thickness

    Forms & Sizes

    Standard Strip:
    0.05–3 mm thick,
    10–600 mm wide

    Precision strip:
    0.01–0.5 mm thick,
    tight tolerance ±0.005 mm

    Foil:
    0.005–0.1 mm thick

    Forms & Sizes

    Seamless Tube:
    OD 6–450 mm,
    WT 1–50 mm,
    1–12 m length

    Welded Tube:
    OD 10–600 mm,
    WT 1–20 mm

    Capillary Tube:
    OD 1–10 mm,
    WT 0.1–2 mm

    Forms & Sizes

    Wire Form:
    Cold Drawn Wire,
    Bright Wire,
    Spring Wire,
    Fine Wire,
    Ultra-fine Wire

    General Diameter:
    φ0.1–10 mm

    Coil Weight:
    50–500 kg,
    customizable tolerance

    Forms & Sizes

    Solid Wire:
    φ0.8–4.0 mm

    Flux-cored Wire:
    φ1.2–4.0 mm

    Welding Rod:
    φ2.0–5.0 mm

    Forms & Sizes

    Powder Form:
    AM 3D Printing Powder,
    Spherical Powder,
    Gas-atomized Powder,
    Water-atomized Powder

    Particle Size:
    10–150 μm

    Sphericity:
    ≥90% for AM grade

    Forms & Sizes

    Cast Ingot:
    φ200–800 mm

    Precision Casting:
    min wall 0.5 mm

    Cast Pipe:
    OD 100–600 mm,
    WT 10–50 mm

    Forms & Sizes

    Forged Bar:
    Φ35–500 mm

    Forged Ring:
    OD 200–2000 mm

    Forging Weight:
    1–5000 kg

    Forms & Sizes

    Fittings Form:
    Elbow, Tee, Reducer, Flange, Cap, Outlet, Lap Joint

    Size range:
    1/2''–24'' (DN15–DN600)

    Wall thickness:
    Sch10–Sch160, STD, XS, XXS

    Pressure Class:
    150–2500 LB

    Forms & Sizes

    Fastening Form:
    Bolt, Nut, Screw, Stud, Washer, Pin, Rivet

    Metric: M3–M64

    Imperial: #4–2.5''

    Length: 6–500 mm

XM-12 Product Description

Overview

XM-12 is a copper-bearing martensitic precipitation-hardening (PH) stainless steel. This datasheet presents the material within the American (ASTM / ASME / AMS / UNS) standard system.

With about 15% chromium, 5% nickel and 3% copper plus niobium, 15-5PH combines high strength and hardness with good corrosion resistance and excellent transverse toughness and ductility. It was designed as a more ductile variant of 17-4PH, with improved through-thickness (short-transverse) properties achieved by a controlled, low-ferrite microstructure. The alloy is martensitic in the annealed (solution-treated) condition and is strengthened by a single low-temperature ageing treatment that precipitates a copper-rich phase. A range of strength levels is obtained by choosing the ageing temperature (the H-condition).

Typical applications include aerospace structural and engine components, valve and pump parts, shafts, fasteners, gears, and nuclear and chemical-process hardware requiring high strength with moderate corrosion resistance.

1. Physical Properties

Typical values, H1025 condition.
Property Value Unit
Density 7.8 g/cm³
Melting range 1400–1440 °C
Elastic modulus 196 GPa
Coefficient of thermal expansion (20–100 °C) 10.8 µm/m·°C
Thermal conductivity (20 °C) 17.8 W/m·K
Specific heat (20 °C) 420 J/kg·K
Structure Martensitic (precipitation-hardening)

2. Chemical Composition (wt %)

Element Symbol Min % Max % Role in Alloy
Iron Fe Balance Base element
Chromium Cr 14.0 15.5 Corrosion resistance; martensite former
Nickel Ni 3.5 5.5 Toughness; martensite stability
Copper Cu 2.5 4.5 Precipitation-hardening phase
Niobium Nb 0.15 0.45 Carbide stabiliser; grain refinement
Manganese Mn 1.00 Deoxidiser
Silicon Si 1.00 Deoxidiser
Carbon C 0.07 Strength; martensite hardness
Phosphorus P 0.040 Residual impurity
Sulphur S 0.030 Residual impurity

3. Mechanical Properties

Typical values by ageing (H) condition, per ASTM A564 / AMS 5659 for UNS S15500.

Condition Tensile strength 0.2% Yield Hardness
H900 ≥1310 MPa (190 ksi) ≥1170 MPa (170 ksi) ~44 HRC
H1025 ≥1070 MPa (155 ksi) ≥1000 MPa (145 ksi) ~35 HRC
H1075 ≥1000 MPa (145 ksi) ≥860 MPa (125 ksi) ~32 HRC
H1150 ≥930 MPa (135 ksi) ≥725 MPa (105 ksi) ~28 HRC

Confirm against the mill test report. Elongation typically ≥10–16% depending on condition.

4. Corrosion Resistance

Environment Performance Notes
Atmospheric / general Good Superior to 400-series martensitic steels
Mild acids (acetic, nitric, dilute) Good At low concentrations
Chloride pitting Moderate Lower than austenitic grades
Stress-corrosion cracking Improved at higher ageing Over-aged (H1100–H1150) gives best SCC resistance
Seawater Limited Not recommended for prolonged exposure

Corrosion resistance is roughly comparable to type 304 in many environments; resistance and SCC behaviour improve with higher (over-aged) ageing conditions.

5. Heat Treatment

A martensitic precipitation-hardening alloy; supplied in Condition A (solution-treated) and hardened by a single low-temperature ageing treatment.

Solution Treatment (Condition A) Approximately 1040 °C followed by cooling to room temperature to form a martensitic structure.

Precipitation Hardening (Ageing) A single low-temperature ageing treatment precipitates a copper-rich phase. The temperature sets the strength level: H900 (~480 °C) gives maximum strength; higher temperatures (H1025, H1075, H1100, H1150) progressively lower strength while increasing toughness and SCC resistance. No quench required after ageing; air cool.

6. Weldability and Joining

Weldable by common fusion methods; matching filler (AWS A5.4 E630 / ER630) is used. A post-weld solution treatment and ageing restores full properties.

Welding Process Applicability Filler / Consumable
GTAW / TIG Good AWS A5.9 ER630
GMAW / MIG Good ER630
SMAW / stick Good AWS A5.4 E630 electrode

Weld in the solution-treated (Condition A) or over-aged condition; re-age after welding to restore strength.

7. Machinability and Fabrication

Machining Guidelines

Parameter Recommendation
Preferred condition Condition A or over-aged (H1150M) for best machinability
Tooling Carbide tooling; rigid setup
Coolant Ample flood coolant

Forming Processes

Process Notes
Cold forming Limited in hardened conditions; form in Condition A
Hot forming ~1150–950 °C; solution treat + age afterward

8. Applications

Industry Typical Components Key Requirements
Aerospace Structural fittings, engine parts, actuators High strength + transverse toughness
Power generation Steam/gas turbine blades, shafts Strength + moderate corrosion resistance
Oil & gas Valve and pump components, shafts Strength + corrosion resistance
General industrial Fasteners, gears, high-strength parts Hardness + machinability

9. Available Product Forms and Standards (ASTM / ASME System)

Product Form ASTM Standard ASME / AMS
Bar, wire and forgings ASTM A564 grade XM-12 ASME SA-564 / AMS 5659
Plate, sheet and strip ASTM A693 grade XM-12 AMS 5862
Forgings ASTM A705 grade XM-12 ASME SA-705
Castings (equivalent) ASTM A747 grade CB7Cu-2
Welding consumables AWS A5.4 E630 / A5.9 ER630

Copper-bearing martensitic precipitation-hardening stainless steel. UNS S15500.

10. Comparison with Related Alloys (XM Designation System)

XM Grade Type Cr % Ni % Best Used For
XM-12 Martensitic PH (Cu) 14–15.5 3.5–5.5 High-strength PH; transverse toughness
XM-13 Martensitic PH 11–12.5 10.5–11.5 Ultra-high-strength PH (different type)
XM-16 Martensitic PH 11.5–13.5 4.5–5.5 High-strength PH (Custom 455, different type)
XM-25 Martensitic PH 11.5–13 8–9 High-strength PH (different type)
XM-27 Ferritic 25–27.5 Corrosion-resistant ferritic (different type)

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