• Chemical Composition (wt%):
  • Carbon (C): 0.15% max
  • Chromium (Cr): 15.00–17.00%
  • Nickel (Ni): 1.25–2.50%
  • Manganese (Mn): 1.00% max
  • Silicon (Si): 1.00% max
  • Phosphorus (P): 0.040% max
  • Sulfur (S): 0.030% max
• Mechanical Properties (annealed condition):
  • Tensile strength: ≥620 MPa
  • Yield strength (0.2% offset): ≥430 MPa
  • Elongation: ≥20%
  • Hardness: ≤235 HB (brinell) or ≤99 HRB (rockwell)
• Physical Properties:
  • Density: ~7.75 g/cm³
  • Thermal conductivity: ~25 W/(m·K) (at 20°C)
  • Coefficient of thermal expansion: ~10.0×10⁻⁶/°C (20–100°C)

Standards

• ASTM A240/A240M: Covers plates, sheets, and strips, designated as 431.
• UNS: Unified Numbering System designation is S43100.
• EN 10088-2: European standard, classified as X5CrNi17-2 (material number: 1.4057).

Equivalent Grades

• USA: UNS S43100, ASTM 431
• Europe: EN 1.4057 (X5CrNi17-2)
• Japan: JIS SUS431
• China: GB 1Cr17Ni2

Applications

• Automotive industry: Components like valve stems, exhaust systems, and high-strength fasteners.
• Aerospace: Parts requiring high tensile strength and resistance to atmospheric corrosion, such as aircraft fittings.
• Oil and gas: Valves, pumps, and shafts for medium-corrosion environments.
• Medical equipment: Surgical instruments and orthopedic implants (due to biocompatibility and strength).
• General engineering: Gear shafts, bolts, and high-strength structural parts in mildly corrosive conditions.

Laser Cutting of 431 Stainless Steel Plate

• Processing Range:
  • Suitable for plate thicknesses typically up to 20mm, depending on laser power (e.g., 3–6 kW fiber lasers handle 1–15mm efficiently; higher-power lasers can cut thicker materials).
  • Capable of cutting complex shapes, precision holes, slots, and custom profiles with minimal setup changes.
• Key Advantages:
  • High Precision: Narrow kerf width (0.1–0.3mm) and tight tolerances (±0.05mm), ideal for intricate designs.
  • Minimal Heat-Affected Zone (HAZ): Reduces material distortion and preserves the mechanical properties (e.g., strength, corrosion resistance) of 431, unlike plasma or oxy-fuel cutting.
  • Clean Edges: Produces burr-free, smooth edges, eliminating the need for post-processing (e.g., grinding).
  • Efficiency: Faster cutting speeds for thin to medium plates compared to mechanical methods (e.g., sawing), with no tool wear.
  • Versatility: Adaptable to various plate sizes and geometries, supporting both small-batch prototyping and large-scale production.