Low alloy high-strength steel is a type of engineering structural steel developed by adding small amounts of Mn, Si, and trace amounts of Nb, V, Ti, Al and other alloying elements to carbon structural steel. The so-called low-alloy refers to the total amount of alloying elements in steel not exceeding 3%. High strength is relative to carbon engineering structural steel. The development principle of low-alloy high-strength steel is to use as few alloying elements as possible to obtain the highest comprehensive mechanical properties, in order to meet the requirements of use and low cost. Low alloy high-strength steel can meet the requirements of various structures in engineering, such as large bridges, pressure vessels, and ships, for high load-bearing capacity, while also reducing the weight of the structure, improving reliability, and saving materials and resources.

This type of steel is mainly used to manufacture various engineering structures that require high strength, such as bridges, ships, vehicles, high-pressure vessels, oil and gas pipelines, large steel structures, etc. Due to the fact that this type of steel can achieve high strength without complex processing or even heat treatment, the quality of engineering structures is greatly reduced. Therefore, this type of steel is used to replace general carbon structural steel.