含窒素高 Mn-Cr 鋼の研究

概要

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we studied the micro-structure, hardness and shock value of high Mn-Cr-V-N steels containg various amounts of N, V and C, after various heat-treatments. When we melted the samples (8kg ingot) by the laboratory high frequency electric furnace by charging the nitrogenized electrolytic manganese for the mother alloy of nitrogen, we could obtain the sound ingots if the nitrogen was added less than about 0.2%, but the bath boiled and the ingots have many blow holes if the nitrogen was added moreover. To obtain the high precipitation hardening by the heat treatment, it is better to contain the higher amount of nitrogen, but, because of the problems of melting above described, it is necessarly to keep it less than about 0.2%. For the content of nitrogen about 0.2%, it seems most adequate to keep V content at about 0.7%. It is better to be quenched from the higher temperature from the standpoint of the hardening, but, because of the grain growth and the decrease of shock value, it must be quenched from about 1100∿1150℃, and tempered at about 700℃. C content is better to be kept less than about 0.2% from the standpoint of the hardness and the shock value.
社団法人日本鉄鋼協会の論文
1950-05-25