What Is Manganese Steel?
Manganese Steel for machine structural use is produced by adding approximately 1% manganese to carbon steel containing 0.3-0.5% carbon. This combination results in steel that varies in tensile strength and wear resistance based on its manganese content.
Heat treatment of manganese steel involves rapid cooling from high temperatures (water toughening treatment) to prevent carbide precipitation and maintain high toughness.
Uses of Manganese Steel
Manganese improves the tension and toughness of mechanical properties, making it suitable for components like connecting rods, front axles, rear axle shafts, ball joints in transmission mechanisms, high-tensile bolts, and U-bolts.
Types of Manganese Steel
There are four main types of manganese steel:
- SMn420: The lowest carbon content among manganese steels, with carbon ranging from 0.17% to 0.23%. Known for its wear durability.
- SMn433: Has a carbon content of 0.30% to 0.36% and is recognized for its impact resistance. It is treated with water-cooled quenching and air-cooled tempering.
- SMn438: Features a carbon content of 0.35 to 0.41% and is treated with oil quenching and rapid quenching for toughness.
- SMn443: The toughest steel in the range with a carbon content of 0.40 to 0.46%. It has high hardness and undergoes the same treatment as SMn438.