Characteristics and application of low alloy high strength structural steel

Low alloy structural steel standard is a unique steel standard system in China. It has been listed as a basic standard in GBT 1591. It is made into a series of low to high strength grades with GB / T700 grades. It is mainly suitable for engineering parts requiring high strength. On the basis of GB / T1591, a number of steel grades such as bridge, boiler and vessel steel have been developed. The composition and properties of these special steels have been greatly adjusted.

Compared with GB / T 700, GB / T1591 has increased the content of Mn and Si, and also contains microalloyed elements such as V, Ti, Nb and Re, which not only improves the strength, but also improves the comprehensive properties, such as wear resistance and corrosion resistance, or has better mechanical and technological properties at medium and low temperature. The low alloy structural steel is mainly rolled into plates and profiles, which are generally used directly without heat treatment for manufacturing bridges, ships, boilers, vehicles and building structures.

In particular, it is pointed out that there is no special low alloy steel standard system abroad, and some steels also contain microalloyed elements and equivalent strength similar to GB / T 1591, but this kind of steel is usually called carbon steel. The similar foreign low alloy steel standards include: ASTM A242, ASTM A529, ASTM A1011, ASTM A1018, ASTM A423, ASTM A714; JIS G 3114, JIS G 3125; EN 10149, EN 10083-1 (2); ISO 4952, ISO 6930, etc.