CRACK-ARREST IN MODERN STEELS AND THEIR WELDMENTS - COMPARISON BETWEEN SMALL AND LARGE-SCALE EXPERIMENTS

The results of a range of different small scale material characterisat ion tests were correlated with the crack arrest temperature at 2/3 the yield strength of a number of modern ferritic steels and their weldme nts. The crack arrest temperature was determined experimentally using large scale structurally representative double tension tests. The comp arison of small and large scale tests indicates that a safe estimate o f the crack arrest temperature for the steels and welds investigated c an be obtained using the nil-ductility transition temperature plus 40- degrees-C. The 50% fracture appearance transition temperature or the 2 0% fracture appearance transition temperature plus 20-degrees-C obtain ed from full thickness drop weight tear test are also reliable measure s of the lower bound crack arrest temperatures.