李星
,
耿鑫
,
姜周华
,
李花兵
,
徐芳泓
,
王立新
钢铁
doi:10.13228/j.boyuan.issn0449-749x.20140719
电渣重熔渣系的组成直接关系到高温合金的冶炼质量和表面质量。分析了高温合金电渣重熔渣系选择的基本要求和组成特点，确定了高温合金电渣重熔常用渣系的基本类型。通过研究高温合金电渣重熔渣系对冶金质量的影响可知：高碱度渣系具有较好的脱硫效果；为了降低渣料中的不稳定氧化物，应在使用前对萤石进行提纯；可以采用改变渣系组元和加入铝粉的方法，从而减少铝、钛等易氧化元素的烧损；选择低熔点渣系，可有效减少和避免含钛高温合金在电渣重熔过程中易出现的锭身表面渣沟、腰带缺陷、锭身分流眼等表面缺陷。提出的高钛低铝型高温合金电渣重熔渣系配比（质量分数）为：CaF265%～70%、Al2O312%～15%、CaO 12%～15%、MgO 3%～8%、TiO22%～5%。高铝低钛型高温合金电渣重熔渣系配比（质量分数）为：CaF260%～65%、A12O315%～20%、CaO 15%～20%、MgO 0～5%、TiO20%～2%。
关键词:
高温合金
,
电渣重熔
,
渣系
,
易氧化元素
,
表面质量
YU Fanghua YANG Guohua Shanghai Institute of Nuclear Research
,
Academia Sinica
,
Shanghai
,
ChinaHAN Rongdian WENG Huimin University of Science and Technology of China
,
Hefei
,
ChinaSHEN Jianian Corrosion Science Laboratory
,
Institute of Corrosion and Protection of Metals Academia Sinica
,
Shenvang
,
China
金属学报(英文版)
The effects of small amount(≥0.05%)of active elements Y and Ce in Fe-25Cr-40Ni al- loy have been investigated on the kinetics of early stage of high temperature oxidation as well as composition and microsructure of oxide film by ion backscattering and slow positron beam.The results show that Y and Ce can reduce evidently the high tem- perature oxidation rate of FeCrNi alloy at early stage and can effectively enhance the Cr_2O_3 formation and retard the oxide formation of Fe and Ni in the surface layer thus the microstructure of the oxide film is improved.Y and Ce enter the oxide film and concentrate within several tens nanometres from surface of the outer layer.The mech- anism of oxidation resistance for Ce is different from Y.Ce can decrease the density of vacancy defects in oxide layer,so the cations are restrained from diffusion outward through vacancies.While Y can control the outward diffusion of cations through va- cancies at the early statge of oxidation(shorter than 12 min),aften that restrained the cations from diffusion outward along grain boundaries up to 60 min oxidation.
关键词:
ion backscattering
,
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,
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,
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