高炭素鋼の炭化物亀裂による欠陥について(II)
1957 年 43 巻 1 号 p. 48-54
詳細
1957 年 43 巻 1 号 p. 48-54
The effects of the addition of hydrogen to 1.4% C file steel; 1.0% C, 1.4% Cr bearing steel; 1.0% C, Cr-W tool steel are investigated. Samples are taken from the outer side of the billets which have been confirmed that any "Acm cementite cracks" were not existed.
The followings are conclusions.
(1) "Acm cementite cracks" are generated in hyper-eutectoid steels by the addition of hydrogen, and the fact has been proved that the main cause of the formation of "Acm cementite cracks" was the existence of super-saturated hydrogen in the steel.
(2) It has also been proved that so-called macro hair-cracks and flakes on fractured surface were only another apperances of "Acm cementite cracks"
(3) The characteristic features of flakes occurence on hyper-eutectoid steel, which have not been able to explain by the use of theories about the flakes occurence on hypoeutectoid steel, can easily be understood by considering the existence of "Acm cementite cracks.
