Abstract
A study was made on the correlation between transition temperature of Charpy characteristics and that of fracture toughness for a low carbon 3.5% Ni steel heat treated in various conditions.
Fracture toughness was measured in terms of COD for crack initiation and represented by fracture appearance transition temperature of press notched Charpy test which is considered to evaluate crack arrestability.
The results are summarized as follows:
(1) A tempered martensite steel has rather low crack arrestability in spite of its relatively good V-notched Charpy characteristics.
(2) A temper-embrittled steel has relatively large COD value in spite of its poor V-notched Charpy characteristics.
