-Plain Carbon Steel

Plain Carbon Steel
• Lowest cost
• Should be considered first in most application
• 3 Classifications
• Low Carbon (less than 0.3% carbon)
• Med Carbon (0.3% to 0.6%)
High Carbon (0.6% to 0.95%)
1. Low Carbon (less than 0.3% carbon)


Low strength, good formability
• If wear is a potential problem, can be carburized (diffusion hardening)
• Most stampings made from these steels
• AISI 1008, 1010, 1015, 1018, 1020, 1022, 1025
2. Med Carbon (0.3% to 0.6%)
Have moderate to high strength with fairly good ductility
Can be used in most machine elements
AISI 1030, 1040, 1050, 1060*
1. High Carbon (0.6% to 0.95%)
Have high strength, lower elongation
Can be quench hardened
Used in applications where surface subject to abrasion – tools, knives, chisels, ag implements.
AISI 1080, 1095.















Alloy Steel
• 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 percents (<5%)
increase strength and hardenability
High alloy: Added in large percents (>20%)
i.e. > 10.5% Cr = stainless steel where Cr improves corrosion resistance and stability at high or low temps