Abstract
A few years ago. the present authors1) investigated on the transformation points and the microstructure of manganese steels and proposed several structural diagrams for specimens cooled under different conditions. These diagrams are, however, not satisfactory owing to the lack of the specimens examined. In the present experiment, several low carbon steels containing different manganese content, used in the previous investigation or freshly prepared were so much carburized as to get hyper eutectoid structure in edge. These specimens were cooled under several conditions, the same as in the previous investigation. By examining the microstructure of a specimen thus heated along the diameter, the change of structure due to carbon content with a constant amount of manganese in the case cooled under the same condition was studied.
From the result, examined the structure of all the specimens cooled under several conditions, the structural diagrams proposed in the previous paper were revised.
