Experimental studies and calculation of crack propagation at the nil ductility temperature of shipbuilding steel

Resistance to crack propagation in low-alloyed steels is verified by the experimental evaluation of ductile-to-brittle transition temperatures. Though, correlations of test results obtained according to used methods with the minimum design temperature of marine structures should be substantiated. The paper suggests a fracture mechanics based formula for the required nil ductility temperature (NDT). An original FEM simulation method with uniform mesh size is applied.