29Cr-4Mo-2Niフェライト系ステンレス鋼の耐孔食性に及ぼす熱処理条件の影響

概要

論文の詳細を見る
The effect of heat treatment on the pitting corrosion resistance of 29Cr-4Mo-2Ni ferritic stainless steel was investigated. The results as follows.(1) The optimum heat treatment of 29Cr-4Mo-2Ni steel is heating at 1000°C and water quenching. In case of addition of Nb and Ti, it is heating at 1100°C and water quenching.(2) In high chrominum ferritic stainless steel, carbon and nitrogen are normally controlled less than 300ppm in the total, but in this investigation a favourable pitting corrosion resistance can be obtained by heating at 1000°C and water quenching even if it contains such a high amount as 770ppm.(3) In case of heating at temperature over 1100°C, there occurs sensitization by the grain boundary precipitation of Cr23C6 and Cr2N and accordingly, the pitting corrosion resistance gets deteriorated.(4) In case of heating up to 800-900°C there occurs precipitation of σ phase and due to lack of Cr and Mo in α phase the pitting corrosion resistance gets deteriorated. The degree of deterioration is not influenced by the amount of carbon and nitrogen, but there is a tendency that it gets rather big by the addition of Nb or Ti.
大同特殊鋼株式会社の論文