- Other elements (besides carbon) can be added to iron to improve mechanical property, manufacturing, or environmental property.
- Example: sulfur, phosphorous, or lead can be added to improve machine ability.
- Generally want to use for screw machine parts or parts with high production rates!
- Examples: 11xx, 12xx and 12Lxx
- Again, elements added to steel can dissolve in iron (solid solution strengthening):
- Increase strength, hardenability, toughness, creep, high temp resistance.
- Alloy steels grouped into low, med and high-alloy steels.
–High-alloy steels would be the stainless steel groups.
–Most alloy steels you’ll use fall under the category of low alloy. > 1.65%Mn, > 0.60% Si, or >0.60% Cu
- Most common alloy elements:
–Chromium, nickel, molybdenum, vanadium, tungsten, cobalt, boron, and copper.
- Low alloy: Added in small percent (<5%)
–increase strength and hardenability
- High alloy: Added in large percent (>20%)
i.e. > 10.5% Cr = stainless steel where Cr improves corrosion resistance and stability at high or low temperature.