How does the elemental content of stainless steel affect the machining of extend

Release time：2020-01-16 18:44 Browse：

1. Chromium (Cr) Content

• Effect: Chromium is essential for corrosion resistance (typically ≥10.5%). High chromium content (e.g., 18% in 304 stainless steel) enhances passive film formation but increases hardness and work-hardening tendency, accelerating tool wear.

• Machining Recommendation: Use wear-resistant tools (e.g., carbide) and control cutting speed to avoid overheating.

2. Carbon (C) Content

• Effect: Carbon improves strength (e.g., high-carbon 440C) but reduces ductility, increasing the risk of cracking during cold working. Low-carbon steels (e.g., 304L) are easier to form but have lower strength.

• Machining Recommendation: Anneal high-carbon steel to improve machinability; optimize die design for cold forging to prevent cracks.

3. Nickel (Ni) Content

• Effect: Nickel (e.g., 8–10% in 304) enhances toughness and fatigue resistance but may cause chip adhesion, affecting surface finish.

• Machining Recommendation: Use sharp tools with sufficient coolant to minimize built-up edge.

4. Molybdenum (Mo) Content

• Effect: Molybdenum (e.g., 2–3% in 316) improves corrosion resistance but increases work-hardening rate and cutting forces.

• Machining Recommendation: Employ low-speed, high-feed machining to avoid tool chipping.

5. Sulfur (S) and Phosphorus (P)

• Effect: Sulfur (e.g., in 303 stainless steel) improves machinability but reduces corrosion resistance; phosphorus increases brittleness, affecting cold workability.

• Machining Recommendation: High-speed cutting is suitable for sulfur-added steels, but avoid using them in highly corrosive environments.

6. Other Elements (Silicon, Manganese)

• Silicon (Si): Increases hardness, accelerating tool wear.

• Manganese (Mn): Enhances work-hardening tendency (e.g., in 201/202 stainless steel).