Fe-9%Ni-4.5%Mn マルテンサイト合金の時効硬化と機械的性質におよぼす Mo 添加の影響

概要

論文の詳細を見る
The age-hardening behaviours of an Fe-9%Ni-4.5%Mn martensitic alloy have been investigated metallographically concerning with hardness, strength and ductility. The effect of molybdenum addition on these properties of the Fe-9%Ni-4.5%Mn alloy has also been studied to obtain a good combination of strength and toughness. The results obtained in this paper are summarized as follows : (1) The age-hardening of the Fe-9%Ni-4.5%Mn martensitic alloy is due to the hardening by coherent strain associated with the two phase decomposition in martensitic matrix and the precipitation of NiMn. The 0.2% proof stress increases with increase of hardness but the embrittlement occurs simultaneously. This brittleness is improved with the precipitation of austenite in the overaging and softening stage. The addition of molybdenum to this alloy hardly changes its hardening behaviours whereas improves its ductility. (2) In the Fe-9%Ni-4.5%Mn alloy containing 6%Mo, the similar age-hardening due to the precipitation of NiMn at 400∿550℃ with that in the Fe-Ni-Mn alloy is found and the age-hardening due to the precipitation of Fe_2Mo is also observed at 500∿700℃. The former hardening mechanism is Mott-Nabarro type and the latter one is Orowan type. These difference is clearly observed in the shape of stress-strain curves. (3) The optimum combination of strength and toughness is obtained in the Fe-9%Ni-4.5%Mn-6%Mo alloy aged at 500℃ for 10 hr having σ_<0.2>=152kg/mm^2, σ_B=162kg/mm^2, δ_u=4.3%, δ_t=12.6% and ψ=37%. The microstructure of this alloy corresponds to the aging stage in which Ni Mn particles are 150∿200Å in diameter, Fe_2Mo particles are about 300Å in diameter and austenite is not yet formed.
社団法人日本鉄鋼協会の論文
1975-08-01

Fe-9%Ni-4.5%Mn マルテンサイト合金の時効硬化と機械的性質におよぼす Mo 添加の影響

スポンサーリンク

概要

著者

関連論文

スポンサーリンク