Fe-Cu合金体系中Cu析出规律

Copper precipitation behavior in Cu-Fe alloys

利用扫描电镜及能谱分析研究了Fe-7.8%Cu和Fe-2.1%Cu两种合金不同温度下铜的析出分布规律,以及合金中MnS夹杂物对铜析出的影响.部分试样加热到1600℃保温20 min后直接淬火得到;其他试样1 600℃保温20 min,炉冷到特定温度再保温20 min后淬火得到.结果表明:Fe-7.8%Cu合金在1600℃下淬火,含铜相在晶界、晶内均有析出;在1200℃下淬火,含铜相沿晶界析出;而1000℃淬火则有较大尺寸的ε-Cu相沿晶界析出.Fe-2.1%Cu合金在1 600℃和1 000℃下淬火,含铜相都沿晶界析出;而800℃淬火ε-Cu相在晶内析出.合金中MnS夹杂可以作为铜析出的有效形核核心.

The precipitation behavior of copper-enriched phases at different temperatures in Fe-Cu alloys and the effect of MnS inclusions on it were investigated by SEM analysis. The samples were heated to 1600 ℃ and kept for 20 min, some of them were waterquenched directly, and the others were furnace-cooled to a predetermined temperature and kept for 20 rain and then quenched. The results showed that in Fe-7.8% Cu alloys, copper-enriched phases precipitated both inside grains and at grain boundaries after water-quenched at 1 600 ℃, copper-enriched phases precipitated mostly at grain boundaries while water-quenched at 1 200 ℃, and there were ε-Cu phases with large size precipitates at grain boundaries after water-quenched at 1 000 ℃. In Fe-2.1% Cu alloys, copperenriched phases precipitated at grain boundaries after water-quenched at 1 600 ℃ and 1 000 ℃, and e-Cu phases were found inside grains after water-quenched at 800 ℃. MnS inclusions could be the effective nucleation substrate of copper precipitation in the alloys.