Views: 0 Author: Site Editor Publish Time: 2025-04-02 Origin: Site
420J2 stainless steel is a martensitic stainless steel (corresponding to Chinese grade 3Cr13), belonging to the 400 series stainless steel, which optimizes the balance between corrosion resistance and hardness by adjusting the carbon (C) and chromium (Cr) content. It mainly improves mechanical properties through heat treatment and is often used in situations requiring high strength and wear resistance.
Chemical composition
| Grade | C≤% | Si≤% | Mn≤% | P≤% | S≤% | Ni≤% | Cr % |
| 1.4028/420J2/3Cr13 | 0.26-0.35 | 1.00 | 1.00 | 0.040 | 0.030 | 0.60 | 12.00-14.00 |
Physical and mechanical properties
Hardness: about HRC 28-32 in annealed state, up to HRC 50-56 after quenching.
Corrosion resistance: better than 410 stainless steel, but weaker than 304; suitable for mildly corrosive environments (such as humid air, fresh water).
Magnetic properties: magnetic (martensitic structure).
Processability: good machinability, but poor weldability (preheating and post-weld heat treatment required).
| Tensile strength(Min) | Yield Strength(Min) | Elongation(Min)% | Hardness(Max) | ||
| Mpa | Mpa | 50mm | HRB | HV | HRC |
| 540 | 225 | 18 | 99 | 247 | 55 |
Typical applications
Tool industry: scissors, razor blades, scalpels, folding knives, table knives, etc.
Industrial parts: shafts, valve parts, pump parts.
Daily hardware: razor blades, watch cases, wear-resistant parts.
Mold: plastic mold (surface polishing required)
Advantages
High hardness: High hardness can be obtained through heat treatment (quenching + tempering), and good wear resistance.
Low cost: More economical than 304/316 stainless steel, suitable for budget-sensitive projects.
Easy processing: Easy to cut and cold process in the annealed state.
Disadvantages
Limited corrosion resistance: not suitable for high-chlorine environments (such as seawater) or strong acid and alkali environments.
Welding difficulty: easy to crack after welding, requiring professional technology.
Low toughness: increased brittleness at high hardness, weaker impact resistance than austenitic stainless steel
Compared with other stainless steel
| Grade | Type | C % | Cr % | Hardness(HRC) | Main Application |
| 420J2 | Martensite | 0.26-0.40 | 12.00-14.00 | 50-55 | Knives, medical equipment |
| 420J1 | Martensite | 0.15-0.25 | 12.00-14.00 | 45-50 | Tools that focus more on resilience |
| 440C | Martensite | 0.95-1.20 | 16.00-18.00 | 58-60 | High-end cutting tools and bearings |
| 304 | Austenite | ≤0.08% | 148.00-20.00 | HB 200 | Food equipment, building decoration |
420J2 is an economical stainless steel material suitable for applications that require high hardness and good wear resistance, such as knives, mechanical parts, and sports equipment. However, due to its low corrosion resistance, additional protection is required in wet or corrosive environments. When selecting this material, its advantages and disadvantages should be weighed according to the specific application requirements.
