Definition - What does Low-alloy Steel mean?
A low-alloy steel is a type of metal mixture composed of steel and another metals that possess desirable properties. Low-alloy steel contains about 1%-5% of alloying elements. Therefore, it possesses precise chemical compositions that provide better mechanical properties that are intended to prevent corrosion.
Corrosionpedia explains Low-alloy Steel
Low-alloy steels typically undergo heat treatment, normalizing and tempering during production. They are also weldable. However, weld heat treatment is necessary in order to avoid weld cracking.
Significant advantages of low-alloy steels over mild steel are:
- High yield strength
- Able to withstand high temperatures
- Good creep strength
- Oxidation resistance
- Hydrogen resistance
- Low temperature ductility
A higher yield strength and creep strength is desirable because low-alloy steels are used to manufacture thin walled pressure vessels. Low-alloy steels such as 0.5 Mo and 12 CrMoVW are used for their good creep properties in steam boilers, refinery crackers and reformers. The upper temperature limit for low-alloy steels is about 600°C (1112°F).