A131 steel plates for low-temperature applications

The designation system for A131 steel is a structured code rather than an arbitrary name. The initial letter indicates the impact-test temperature: 'A' corresponds to 0°C (often exempt from impact testing), 'D' to -20°C, 'E' to -40°C, and 'F' to -60°C. An 'H' in the middle denotes a high-strength grade, while the final two digits represent the yield strength in kgf/mm² (e.g., AH36 corresponds to 355 MPa). Based on this logic, AH36 and Grade A belong to distinct strength categories; one is not simply an "upgrade" of the other.

Errors in material selection often occur when users focus solely on strength while overlooking the required toughness grade. Although all three share a yield strength of 355 MPa, AH36 steel requires impact testing at 0°C, DH36 at -20°C, and EH36 at -40°C. Because their smelting processes and delivery conditions differ, the price variation is driven primarily by these factors rather than by strength alone. When placing an order, it is essential to specify four parameters: strength grade, toughness grade, plate thickness, and delivery condition.

BBN Steel supplies A131 steel plates—including Grades A, B, D, and E, as well as AH32, AH36, DH36, and EH36—manufactured in accordance with classification society standards. This includes impact testing and Z-direction (through-thickness) testing, with third-party inspection also available. Providing the full grade designation and plate thickness when requesting a quote will help minimize the need for further technical clarification.