What is the impact toughness of DH32 steel plate at -20℃

Impact toughness is a measure of a material's ability to resist fracture under impact loading. It is typically measured by subjecting a material to a Charpy V-notch (CVN) impact test, which involves striking a notched specimen with a pendulum and measuring the energy absorbed during fracture.

DH32 steel plate is a type of high-strength low-alloy (HSLA) steel commonly used in shipbuilding. The impact toughness of DH32 steel plate at -20℃ can be determined through CVN testing. However, the actual value of the impact toughness will depend on several factors, including the specific heat treatment and processing of the steel plate.

Generally speaking, HSLA steels like DH32 are known for their good impact toughness, even at low temperatures. However, without more information about the specific composition and processing of the DH32 steel plate in question, it's difficult to provide an accurate estimate of its impact toughness at -20℃.