What core advantages does alloy structural steel have over plain carbon steel?

Plain carbon steel has poor hardenability, so thick workpieces cannot achieve uniform strength after heat treatment and crack easily under impact or cyclic loads. Alloy structural steel features excellent deep hardenability, allowing consistent mechanical properties across large cross-section forgings. It delivers higher yield strength, stronger fatigue resistance and far better low-temperature toughness. Its tempered structure resists deformation under alternating stress, extending component service life greatly, while its raw material and processing costs remain much lower than superalloys or titanium alloys for general heavy-duty structures.