Is 1.4303 stainless steel the same as 305?
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1.4303 Stainless Steel vs. 305 Stainless Steel: Key Comparisons
1. Grade Equivalence
| Standard System | 1.4303 (EN) | 305 (ASTM) |
|---|---|---|
| Europe (EN) | 1.4303 (X4CrNi18-12) | No direct EN equivalent (matched by chemical composition) |
| USA (ASTM) | UNS S30500 | 305 (UNS S30500) |
| Japan (JIS) | SUS305J1 (partial standards) | SUS305 |
| China (GB) | 1Cr18Ni12 (old grade) | 06Cr18Ni12 (new grade) |
2.1.4303 Stainless Steel vs. 305 Stainless Steel:Chemical Composition (Mass Fraction, %)
| Element | 1.4303 (EN 10088-2) | 305 (ASTM A240) |
|---|---|---|
| Carbon (C) | ≤0.07% | ≤0.12% |
| Chromium (Cr) | 17.0–19.0% | 17.0–19.0% |
| Nickel (Ni) | 11.0–13.0% | 10.5–13.0% |
| Manganese (Mn) | ≤2.0% | ≤2.0% |
| Silicon (Si) | ≤1.0% | ≤0.75% |
| Phosphorus (P) | ≤0.045% | ≤0.045% |
| Sulfur (S) | ≤0.030% | ≤0.030% |
Core Differences:
1.4303's lower carbon (≤0.07% vs. 305's ≤0.12%) makes it more suitable for welding.
305 has a slightly lower Ni minimum (10.5% vs. 11.0%), but Ni ranges overlap (11.0–13.0%), resulting in negligible performance differences.
3. 1.4303 Stainless Steel vs. 305 Stainless Steel: Mechanical Properties
| Property | 1.4303 | 305 |
|---|---|---|
| Tensile Strength | 500–650 MPa | ≥515 MPa |
| Yield Strength | ≥190 MPa | ≥205 MPa |
| Elongation | ≥45% | ≥40% |
| Work Hardening Rate | Low (excellent deep drawing) | Low (excellent deep drawing) |
4.1.4303 Stainless Steel vs. 305 Stainless Steel: Corrosion Resistance & Applications
General Corrosion Resistance:
Similar performance in atmospheric, water, and food-contact environments.
Welding Scenarios:
1.4303's low carbon minimizes intergranular corrosion risk post-welding, no heat treatment needed.
305 requires caution for welding due to higher carbon.
High-Temperature Oxidation:
305's lower Si (≤0.75%) offers slightly better oxidation resistance above 600°C.
1.4303 Stainless Steel vs. 305 Stainless Steel: Typical Applications
| Application | 1.4303 | 305 |
|---|---|---|
| Deep Drawing/Cold Forming | Kitchen sinks, tableware, electronic casings | Automotive fuel tanks, pressure vessels, bellows |
| Welded Structures | Food machinery, chemical equipment (welding required) | Complex formed parts in non-welded scenarios |
| High-Temperature Environments | Rarely used | High-temperature furnace components, heat exchangers |
| Medical Equipment | Welded surgical instruments, implants | Non-welded medical parts (e.g., syringes) |
5. Interchangeability
Can Be Interchanged When:
Non-welded, room-temperature environments (e.g., architectural trim, cold-formed parts).
Carbon content limits are not strict (e.g., standards allowing ≤0.12% C).
Cannot Be Interchanged When:
Welded structures (1.4303's low carbon is critical for corrosion resistance).
High temperatures (>600°C) or strongly oxidizing media (305's lower Si improves oxidation resistance).
Specific standards mandate one grade (e.g., EN 10088-2 for 1.4303 or ASTM A240 for 305).
6.1.4303 Stainless Steel vs. 305 Stainless Steel: Cost & Workability
Cost:
1.4303 is slightly more expensive (≤5% premium) due to low-carbon processing.
Workability:
Cold Forming: Both excel in deep drawing and spinning.
Welding: 1.4303 offers better weldability (no interpass temperature control needed); 305 requires post-weld corrosion checks.
Machining: Slightly higher cutting resistance in 305 due to higher carbon, but differences are minimal.
