A514 grade P quenched and tempered steel, Q345B low alloy steel plate composition: 1) Low carbon: Due to the high requirements for toughness, weldability and cold forming properties, its carbon content does not exceed 0.20%; 2) Add manganese-based alloying elements; 3) Adding auxiliary elements such as niobium, titanium or vanadium: a small amount of niobium, titanium or vanadium forms fine carbides or carbonitrides in the Q345B steel, which is conducive to obtaining fine ferrite grains and improving the strength and toughness of the steel; In addition, adding a small amount of copper (≤0.4%) and phosphorus (about 0.1%) can improve the corrosion resistance. Adding a small amount of rare earth elements can desulfurize and degas, purify steel, improve toughness and process performance.
Phosphorus element (P element) is brought into steel by ore. Generally speaking, phosphorus is also harmful element. Although phosphorus can increase the strength and hardness of A514 grade P quenched and tempered steel etc. steel, it also causes the decrease of plasticity and impact toughness. Especially at low temperature, it makes steel significantly brittle, which is called "cold brittleness". The higher the phosphorus content is, the greater the cold brittleness is. Therefore, the phosphorus content in A514 grade P quenched and tempered steel etc. steel is strictly controlled.
We have 4 typical production lines, which can produce hot rolled Seamless, LSAW, ERW and SSAW pipes. SSAW pipe production line range is OD 219.1mm-3500mm, wall thickness 3.2mm-25.4mm. Product A514 grade P quenched and tempered steel annual capacity is 200 thousand tons.
