The company's main steel plate varieties: A514 Gr P quenched and tempered steel, boiler pressure vessel plate, low-alloy plate and high-strength plate, bridge plate, alloy plate, carbon steel, wear-resistant plate, pipeline steel, nuclear power steel, wind power and hydropower steel, ship plate, building structural steel, Die steel, military steel plate, hydrogen steel plate and various special steels, etc.
What is the difference between Q345B steel and Q345A steel? A514 Gr P quenched and tempered steel, Q345B steel and Q345A steel have slight difference in chemical composition: Q345A steel: C ≤ 0.20, Mn ≤ 1.7, Si ≤ 0.55, P ≤ 0.045, S ≤ 0.045, V 0.02 ~ 0.15; Q345B steel: C ≤ 0.20, Mn ≤ 1.7, Si ≤ 0.55, P ≤ 0.040, S ≤ 0.040, V 0.02 ~ 0.15. The difference between Q345B steel and Q345A steel is mainly in A and B behind the steel grade, Q345A steel grade is not subject to impact; Q345B steel grade needs 20 ℃ room temperature impact test.
Sulfur is a very harmful element in A514 Gr P quenched and tempered steel steel. The presence of sulfur will increase the hot brittleness of steel, reduce the various mechanical properties of A514 Gr P quenched and tempered steel steel, and reduce the weldability, impact toughness, fatigue resistance and corrosion resistance of steel.
In order to improve the A514 Gr P quenched and tempered steel corrosion resistance and decoration of steel, it is an important content of steel production method to plating or coating a protective layer on the surface of plastic processed steel. The material of protective layer is divided into metal and non-metal. The metal protective layer adopts the methods of electroplating, hot plating and chemical plating.
