GB/T 10Cr17 Stainless Steel: Martensitic Stainless Steel for Hardness-Critical Applications
GB/T 10Cr17 (equivalent to AISI 430F/431 in international standards) is a martensitic stainless steel grade characterized by high hardness, moderate corrosion resistance, and excellent wear resistance after heat treatment. With a chromium content of 16-18% and carbon content of 0.08-0.15%, this grade achieves a balanced combination of mechanical strength and machinability, making it ideal for precision components, surgical instruments, and high-stress industrial parts. This article provides a technical breakdown of its chemical composition, mechanical properties, heat treatment processes, and application guidelines.
1. Chemical Composition (GB/T 1220-2007 Standard)
| Element | Content Range | Function |
|---|---|---|
| Carbon (C) | 0.08-0.15% | Enhances hardness and strength; higher content improves heat treatment response but reduces weldability |
| Chromium (Cr) | 16.00-18.00% | Primary corrosion-resistant element; forms Cr₂O₃ passive layer for moderate atmospheric/oxidizing resistance |
| Manganese (Mn) | ≤ 1.00% | Deoxidizer; improves hot workability and partially replaces nickel for cost efficiency |
| Silicon (Si) | ≤ 1.00% | Enhances oxidation resistance at elevated temperatures; strengthens ferrite phase |
| Phosphorus (P) | ≤ 0.040% | Impurity; minimized to prevent embrittlement and reduce intergranular corrosion risk |
| Sulfur (S) | ≤ 0.030% | Improves machinability in free-cutting variants (e.g., 10Cr17S); controlled to avoid hot cracking |
| Nickel (Ni) | ≤ 0.60% | Residual element; limited to maintain martensitic structure and cost-effectiveness |
2. Mechanical Properties (After Heat Treatment)
- Tensile Strength (σb): ≥ 590 MPa (quenched and tempered condition; higher than austenitic grades)
- Yield Strength (σ0.2): ≥ 390 MPa (suitable for load-bearing components in mechanical systems)
- Elongation (δ): ≥ 15% (lower than austenitic grades due to martensitic structure)
- Hardness (HRC): 38-45 (after quenching at 980-1040°C + tempering at 200-400°C)
- Impact Toughness (CVN): ≥ 20 J at 20°C (reduced toughness at sub-zero temperatures)
3. Heat Treatment Processes
- Annealing: Heat to 780-850°C, slow cool in furnace to ≤ 600°C (softens to ≤ 220 HB for machining; structure: ferrite + carbides).
- Quenching: Heat to 980-1040°C, oil or air quench to form martensite (achieves maximum hardness; risk of distortion in complex shapes).
- Tempering: Reheat to 200-400°C (low temp: retains hardness for cutting tools; 500-700°C: improves toughness for structural parts).
- Stress Relieving: Heat to 600-700°C for welded components to reduce residual stresses (avoids dimensional instability).
- Nitriding (Optional): Surface treatment at 500-580°C to achieve ≥ 1000 HV hardness (for wear-resistant applications like valve seats).
4. Key Application Scenarios
Precision Engineering
Shatfs, gears, and pump components in hydraulic systems; valve stems and spindle assemblies requiring dimensional stability under load.
Medical & Surgical Instruments
Scalpel blades, dental probes, and orthopedic tools (corrosion-resistant in sterilization environments; hardness retains sharp edges).
Automotive Components
Exhaust valve seats, fuel injectors, and trim parts (resists thermal fatigue and abrasive wear; compatible with lead-free fuels).
Cutlery & Hardware
High-end kitchen knives, scissors, and locking mechanisms (superior edge retention vs. austenitic grades; polishes to mirror finish).
5. Comparison with Related Grades
| Grade | Type | Key Property | Typical Use |
|---|---|---|---|
| GB/T 10Cr17 | Martensitic | Hardness 38-45 HRC; moderate corrosion resistance | Precision parts, surgical tools, cutlery |
| GB/T 20Cr13 | Martensitic | Higher toughness (12% Cr); lower hardness (≤ 35 HRC) | Turbine blades, structural fasteners |
| GB/T 30Cr13 | Martensitic | Higher strength (0.26-0.35% C); reduced weldability | Spring clips, bearing races |
| AISI 420 | Martensitic | Higher carbon (0.15-0.30%); hardness up to 50 HRC | Mold cavities, shear blades |
6. Processing & Handling Recommendations
- Machining: Perform in annealed state (≤ 220 HB); use carbide tools with positive rake angles and coolant to avoid work hardening.
- Welding: Preheat to 200-300°C and post-weld temper at 600-700°C to prevent cold cracking; use AWS E/ER410 filler metal.
- Corrosion Limitations: Avoid prolonged exposure to chloride solutions or acidic environments (pitting resistance equivalent ≤ 18 PREN).
- Surface Finishing: Passivate with 20-30% nitric acid after polishing to enhance corrosion resistance of the chromium oxide layer.
- Quality Control: Verify hardness via Rockwell testing (HRC) and microstructure via metallographic analysis to confirm martensite transformation.
7. Request a Custom Quote for GB/T 10Cr17 Stainless Steel
For precision-machined components, heat-treated bars, or custom profiles in GB/T 10Cr17, contact our technical team with your specifications (dimensions, heat treatment requirements, and quantity). We provide mill-certified material with full traceability and export packaging for global shipments.