Technical key points of LR D steel plates and so on marine steel production

There are many technical points of LR D steel plates etc. marine steel production. Generally, the key points are:

1. Marine steel cleanliness requirements:
For LR D steel plates and A131 grade A mild steel, S should be less than 0.008, and P is less than 0.015. For A131 grade E marine steel, S is less than 0.005%, P is less than or equal to 0.010%. For naval ships steel plates, the steel mill should ensure NDT≤－550C, S≤0.002%, P≤0.005%，≤40ppmN、≤10ppmO and ≤1.0ppmH. The refining process is essential.

2. LR D steel plates and A131 grade A mild steel can be delivered in hot rolling and controlled rolling station. A131 grade E marine steel are allowed to be used with normalizing or hot mechanical rolling.

3. Quality requirements for LR D steel plates and so on marine steel. It includes requirements for shape and dimensional accuracy, requirements for ultrasonic flaw detection and performance stability.

At present, most steel mills that have rolling conditions have passed approval to produce LR D steel plates, A131 grade A mild steel and A131 grade B marine steel. But for A131 grade E marine steel and high strength shipbuilding steel, please refer to BBN steel etc. powerful steel mills.