DIN 1.2316 ESR Tool Steel
🧠 What is DIN 1.2316 ESR Tool Steel?
DIN 1.2316 ESR is a stainless tool steel known for its exceptional corrosion resistance, hardness, and surface finish.
The ESR (Electro Slag Remelted) process significantly enhances its cleanliness and homogeneity, making it an ideal material for precision tooling, especially in plastic injection molding environments where corrosive or abrasive plastics are used.
🧪 Detailed Chemical Composition
| Element | % Composition | Function |
|---|---|---|
| Carbon (C) | 0.33–0.45 | Increases hardness and wear resistance |
| Chromium (Cr) | 15.0–17.0 | Provides corrosion resistance and hardenability |
| Molybdenum (Mo) | 0.80–1.20 | Improves strength, hardness, and resistance to pitting |
| Manganese (Mn) | ≤ 1.00 | Aids in deoxidation and strength |
| Silicon (Si) | ≤ 1.00 | Improves strength and tempering resistance |
| Phosphorus (P) | ≤ 0.030 | Impurity, should be minimized |
| Sulfur (S) | ≤ 0.030 | Impurity, reduces toughness if too high |
The high chromium and molybdenum content are responsible for its excellent corrosion resistance, even better than 1.2083 in some conditions.
🔍 ESR (Electro Slag Remelting) – Why It Matters
The ESR process refines the steel by:
- Removing non-metallic inclusions
- Improving structural homogeneity
- Enhancing polishability and toughness
Benefits:
- Superior surface finish
- Lower risk of tool failure due to internal defects
- Improved machinability
- More consistent mechanical properties
🛠 Mechanical & Physical Properties (Approximate)
| Property | Value |
|---|---|
| Hardness (HRC) | 48–56 (after hardening and tempering) |
| Density | ~7.7 g/cm³ |
| Tensile Strength | Up to 1600 MPa |
| Thermal Conductivity | ~20–25 W/m·K |
| Corrosion Resistance | Excellent (similar to stainless 420 but tougher) |
🧰 Common Applications
⚙️ Plastic Molding:
- Molds for corrosive plastics like PVC, acetates, fire-retardant materials
- Molds requiring high polish or mirror finishes
- Medical and optical lenses molds
🧼 Food & Pharma Industry:
- Components requiring frequent cleaning
- Tools exposed to moist or chemical-rich environments
🛡 Other Uses:
- Valve parts
- Cutting dies
- Screws or components in moist or corrosive areas
🔥 Heat Treatment Guidelines
- Soft Annealing:
- 750–800°C
- Slow furnace cooling
- Results in ~220 HB hardness for machining
- Hardening:
- 1000–1050°C (holding time: 20–30 min depending on size)
- Oil or air quenching
- Tempering:
- 250–300°C
- Minimum of two tempering cycles recommended
- Achieves final hardness of 48–56 HRC
- Stress Relieving (Post-Machining):
- 600–650°C for 1–2 hours
- Reduces internal stresses before hardening
🔄 Comparison with Similar Grades
| Grade | Key Differences |
|---|---|
| 1.2083 (X40Cr14) | Similar corrosion resistance, slightly less toughness and polishability |
| H13 (1.2344) | Higher toughness and hot strength, lower corrosion resistance |
| 420 Stainless | Similar corrosion resistance, not ESR processed, less uniform structure |
| 1.2316 (non-ESR) | More impurities, lower polishability, higher risk of defects in high-finish parts |
✅ Advantages of Using DIN 1.2316 ESR
- Long tool life even with aggressive polymers
- Reduced maintenance (resists rust and pitting)
- Excellent surface finish potential (optical-grade polishing)
- Stable mechanical properties under demanding conditions
- Less downtime due to tool failures
⚠️ Limitations
- Higher material cost (due to ESR processing)
- More brittle than high-toughness hot-work steels like H13
- Requires careful heat treatment to prevent cracking