ASTM A588 High Strength Low Alloy Structural Steel

ASTM A588 is a high-strength low-alloy structural steel, which is divided into 4 grades: A588GrA, A588GrB, A588GrC, and A588GrK. Steel plates are used in welded, riveted and bolted structures, but are mainly used in welded bridges and buildings where weight reduction or increased life is required. The atmospheric corrosion resistance of this steel is significantly better than copper-containing or copper-free carbon structural steel in most environments. When fully exposed to the atmosphere, this steel is suitable for many occasions in the bare state, and the limited material The thickness is not more than 200mm.

Disadvantages of carbon steel:

(1) Low hardenability. In general, the maximum hardened diameter of carbon steel water quenching is only 10mm-20mm.

(2) The strength and yield strength are relatively low. For example, the σs of ordinary carbon steel Q235 steel is 235MPa, while the σs of low-alloy structural steel 16Mn is above 360MPa. The σs/σb of 40 steel is only 0.43, which is much lower than that of alloy steel.

(3) Poor tempering stability. Due to the poor tempering stability, when carbon steel is quenched and tempered, a lower tempering temperature is required to ensure higher strength, so that the toughness of the steel is low; in order to ensure better toughness, high tempering temperature is used. The strength is low at high temperature, so the comprehensive mechanical properties of carbon steel are not high.

(4) The requirements for special performance cannot be met. Carbon steel is often poor in oxidation resistance, corrosion resistance, heat resistance, low temperature resistance, wear resistance and special electromagnetic properties, and cannot meet the needs of special performance.