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文中首先从热力学分析了电渣重熔0C_(25)Al_5时将渣中稀土氧化物还原成稀土进入合金中的可能性,进而从活度、熔体性质及正交试验确定了新的电渣系——稀土渣系的合理组成及相匹配的冶炼工艺条件。实验表明稀土渣是电渣重熔加稀土的一种好方法,它能往0Cr_(25)Al_5中加入约0.02％稀土,该渣还具有较强的去H、O、N脱S、P及去夹杂能力,使合金的清洁度得到提高,进一步提高了0Cr_(25)Al_5合金的质量,使在1350℃的寿命达60小时以上,常温韧性及寿命和伸长率得到了改善。长期的生产实践证明,Fe—Cr—Al电热合金加稀土后能显著提高其质量。但目前一般均采用稀土金属直接加入法,这种方法有不少缺点,如稀土回收率很低,只达7—15％,这对我国宝贵资源的利用极不合理;其次,由于稀土的大量烧损,那些比重大、熔点高的稀土氧化物必然有相当部份以夹杂的形式残留于合金中而弄脏了合金,使稀土钢的低倍组织往往不合格;又由于稀土是一种良好的吸氢物质,生产中加入稀土前一般均未进行予脱氢,因此随同稀土的加入将带入大量氢气,钢丝厂生产中发现浇铸稀土FeCrAl时,有大量气体排出致使金属上涨,降低了金属回收率。为了充分发挥稀土元素的作用,合理利用我国资源,“独立自主、自力更生”地发展我国的稀土钢系统,走自己的利用稀土的道路。本研究在于建立一种适合于电渣重熔的新的稀土加入法——稀土还原加入法。因此建立一个含稀土氧化物的新渣系,弄清稀土渣还原的物理化学过程及结合FeCrAl的冶炼全面考查稀土渣的性能,是这项工作的中心内容。
In the paper, the possibility of reducing rare earth oxides to rare earths into REE by 0C_ (25) Al_5 electroslag remelting has been analyzed from the thermodynamics. Then, the new electroslag was determined from the activity, melt properties and orthogonal test Department - rare earth slag system and the reasonable composition of the smelting process conditions. Experiments show that rare earth slag is a good method of electroslag remelting plus rare earth, which can add about 0.02% rare earth to 0Cr_ (25) Al_5, the slag also has a strong de-H, O, N off S, P and To inclusions ability to improve the cleanliness of the alloy to further improve the quality of 0Cr_ (25) Al_5 alloy, so that the life of 1350 ℃ for 60 hours or more, room temperature toughness and life expectancy and elongation have been improved. Long-term production practice has proved that Fe-Cr-Al alloy plus rare earth can significantly improve its quality. However, rare earth metals are generally added directly into the process. This method has many shortcomings. For example, the rare earth recovery rate is very low, only up to 7-15%, which is extremely unreasonable for the use of precious resources in our country. Secondly, due to the large amount of rare earth Burning, the proportion of large, high melting point rare earth oxides must have a considerable part of the inclusions remain in the alloy and dirty the alloy, so that the rare earth rare earth microstructure often unqualified; and because the rare earth is a good Of the hydrogen-absorbing material, production before adding rare earth are generally not to be dehydrogenated, so with the addition of rare earth will bring a lot of hydrogen, found in the production of wire factory rare earth FeCrAl rare earth, a large number of gas emissions led to the metal rose, reducing the metal Recovery rate. In order to give full play to the role of rare earth elements, the rational use of our resources, “independent, self-reliance,” the development of China’s rare earth steel system, take their own path of using rare earth. This study is to establish a new rare earth addition method suitable for electroslag remelting - rare earth reduction addition method. Therefore, to establish a new slag system containing rare earth oxides, to understand the physical and chemical processes of reduction of rare earth slag and smelting FeCrAl comprehensive examination of the performance of rare earth residue is the centerpiece of this work.