电渣冶金与电渣熔铸在中国的发展

中国电渣冶金起步于1958年,至今所有特殊钢厂均建有电渣冶金车间,拥有工业电渣炉86台,年生产能力10万吨.产品包括优质合金钢与超级合金243个牌号.中国冶金工作者在电渣炉型结构、电渣重熔(ESR)工艺、电渣熔铸(ESRC)异型铸件、制备大钢锭及电渣重熔机理方面取得重大成就,成果得到国外同行认可.     

电渣重熔技术的新发展

论述电渣重熔技术的新进展 ,主要介绍可控气氛电渣重熔、导电结晶器电渣重熔、快速电渣重熔、电渣重熔 冷壁感应引导等技术 ,这些技术使电渣重熔冶金焕发了新的活力 ,得以进一步的发展。     

在强氧化气氛下的低碳低硅百吨级电渣锭生产

研究开发了在强氧化气氛下重熔低C(～0.15％)、低Si(≤0.05％)电渣钢确保冶金质量的电渣重熔技术。据此,生产了单重百吨以上的石油化工高压容器锻件用大型电渣锭10根。产品检验结果表明性能优良。     

电渣冶金法生产大型钢锭综述

介绍了采用电渣重熔、电渣焊接、电渣浇注和电渣热封顶法生产大型钢锭的工艺,并从钢锭质量、节能、成本等方面对比了上述4种方法的工艺特点.电渣重熔法生产的大型钢锭纯净度和组织均匀性较高,产品质量较好,但工艺设备复杂;电渣焊接法、电渣浇铸法和电渣热封顶法相比电渣重熔法,工艺和设备简单,能耗、成本较低,但产品质量较差.     

电渣重熔超低硫大型钢锭

生产超低硫大钢锭技术的开发被认为是最近十年左右炼钢的主要进展[1]。本研究充分发挥电渣冶金的强制脱硫优势,开发了重熔百吨以上锻件用大型电渣锭获得超低硫(≤0.0020％)的电渣重熔技术。将其应用于200t电渣炉,迄今已连续生产不同钢种90～180t重的电渣锭数十根,最大锻件约130t。所有产品中的硫含量都不超过0.0020％,部分产品低达0.0005％。应用所开发的超低硫技术,不会使生产成本增加。     

13Cr9Mo2Co1NiVNbNB钢电渣重熔工艺中试研究

对FB2材质母材冶炼、电渣重熔过程中渣系及脱氧制度等关键技术开展了研究。电渣重熔中试试验结果表明,采用Ca F2-Al2O3-Ca O-Mg O-Si O2-B2O3六元渣系、惰性气体保护、铝和硅钙复合脱氧的重熔工艺参数能满足产品技术要求。     

电渣重熔铸铁渣系的试验研究

介绍了对铸铁进行电渣重熔的一些试验结果,对提出的50?F2、30?O、10%Al2O3、5%MgO、5%SiO2五元渣进行了熔点、粘度的测定与分析;多炉电渣重熔试验结果表明,该渣系对铸铁电渣重熔有较好的适应性.     

核反应堆堆芯用HEA304电渣锭的试制

HEA304钢电渣重熔后易出现碳、氮含量及晶粒度超标。经过对电渣重熔渣系及电渣工艺的摸索试验,确定电渣重熔渣系及工艺要点,生产出优质的核材用HEA304锻件。     

炉渣成分变化对电渣重熔过程影响的数值模拟

电渣重熔过程中,炉渣成分会发生连续变化,使渣池、渣壳的热物性参数也处于不断的变化之中。渣池及渣壳热物性参数的变化会影响电渣重熔过程。本文根据重熔过程中渣池、渣壳的变化及炉渣热物性参数变化(导热系数及电导率),对重熔过程的影响进行了模拟。通过与未考虑炉渣成分变化及渣壳、渣池热物性参数变化两种情况的重熔过程比对,揭示了炉渣成分变化对电渣重熔过程温度分布的影响。     

核电用大型钢锭电渣重熔工艺模拟及生产应用

论证了应用于核电主管道和12%Cr 转子钢用百吨级巨型电渣钢锭重熔过程数学模型,形成电渣重熔工艺过程三维数值模拟计算程序ESR3D.模拟了电渣重熔全过程,包括电极熔化,金属熔滴自由下落,金属熔池的形成,金属熔池和渣池的上升、移动,三组电极分别更换,在线安装上结晶器,钢锭在水冷结晶器中凝固等.模拟并优化的电渣重熔工艺应用于生产80～120t大型电渣钢锭,其质量满足核电和超超临界火电机组技术要求.     

电渣熔铸钢锭微观组织的模拟研究

电渣熔铸中的工艺参数决定金属熔池的形状和微观晶粒的尺寸及取向,并最终影响熔铸钢锭的质量。本文采用元胞自动机法,借助MATLAB软件,对电渣熔铸钢锭微观组织进行数值模拟研究,同时研究了渣池温度、侧面换热系数、底部换热系数对熔池形状和晶粒取向的影响,为实际生产提供了理论依据。     

GH132高温合金炉底辊电渣熔铸工艺实践

采用电渣熔铸+热处理工艺,代替铸造+锻造+热处理工艺成功制造了连铸生产线上GH132高温合金炉底辊.采用五元渣系、4 000 A电流和57 V电压生产的炉底辊铸件,经720℃+16 h+空冷处理后,其各项力学性能指标均达到炉底辊铸件的设计要求.     

Factors influencing power consumption and power-saving measures in ESR process

Since the USA patent of electroslag remelting(ESR) metallurgy was held by P. K. Hopkins in 1940, the ESR technology has now entered a relatively mature stage after a 70-year history of development. At present, the annual capacity of ESR steels around the world is approximately 2 million tonnes. ESR metallurgy emerged in China in 1958. Since then, electroslag furnaces were gradually installed in Chinese special steel plants. At present, there are more than 200 electroslag remelting furnaces in the metallurgical workshops of these steel plants with an annual production capacity of about 500,000 tonnes of ingots and components made of about 200 varieties of steels, including high quality steels and superalloys. This ESR technology is used as a special remelting and refining method for producing high quality steels and superalloys. However, traditional ESR technology has the disadvantages of environmental pollution and extremely high specific power consumption. High power consumption restricts, to a certain degree, the competitiveness of ESR steels in the marketplace. The measures of power saving in ESR have been researched in recent years. In this paper, some factors influencing power consumption, such as filling ratio, slag system, slag amount, melting rate and furnace structure are reviewed, and several new ESR technologies for power saving are proposed.     

压铸模具钢的选择与提高压铸模寿命的途径

从压铸模具钢3Cr2W8V和4Cr5MbSiV1(H13)的材质和热处理工艺方面分析了提高压铸模寿命的途径。认为选择电渣熔铸钢，采用合理的预处理、热处理工艺，以及在压铸生产过程中进行消除应力回火，通过模具的表面强化和防粘模处理能显著提高压铸模的使用寿命。此外，对模具延寿工作的趋势进行了展望。     

高速钢坯料制备工艺的问题与对策

现行的高速钢坯料制备工艺主要是电渣重熔和粉末冶金两大类。其中电渣重熔锭比普通冶炼模铸钢锭的组织致密,明显改善了初始共晶碳化物的分布,但是电耗过高,生产中产生的氟化物对环境的污染严重;粉末冶金虽然从根本上解决了碳化物偏析和粗大的问题,但其工艺复杂,成本过高,应用受到限制。而半固态连铸工艺既解决了初始碳化物偏析和粗大问题,又克服了电渣重熔中电耗高、环境污染以及粉末冶金成本高的缺点,是值得重视的一个新工艺。     

Production of High Quality Castings by the Centrifugal Electroslag Method

Abstract

The Ukrainian-based E. O. Paton Electric Welding Institute has developed new technology for the production of high-quality castings using the centrifugal electroslag casting process (CESC). The technology consists of preparing molten metal in an electroslag crucible furnace from where it is poured, together with the slag, into a rotating casting mould. The authors show that the initial metallic materials may consist of rolled off-cuts, worn-out parts and tools, lumpy waste, and cast stock from continuous casting plants. The use of electro-slag melting technology ensures that there is no loss of alloying elements from the basic charge materials and that there is an absence of harmful contaminants. It is said that the energy characteristics of the electroslag crucible furnace are not inferior to those of induction or arc furnaces. The process technology facilitates the production of high-quality close-to-form castings. The paper presents results of integrated studies of CESC casting quality and describes the method employed in the effective refining of the metal structure. The results of the authors' studies, together with industrial testing and evaluation, show that CESC castings can compete with forgings and stampings in the manufacture of special-purpose components.     

The P/M processing of high-nitrogen stainless steels

The production of high-nitrogen steels requires the utilization of unique melting and casting technologies such as pressurized electroslag remelting; however, production can be accomplished via powder metallurgy techniques utilizing lower-cost modifications to existing gas-atomization equipment and, in the solid state, by the development of novel processing schemes and equipment. This article describes two methods, one liquid- and one solid-state processing, for the production of high-nitrogen stainless steels—pressurized gas atomization and solid-state nitriding in a mechanical-fluidized vacuum machine.     

铸造合金CoCrMoW锻造工艺的研究

通过对CoCrMoW合金电渣锭在两种不同的保温制度下保温后进行两种不同的锻造变形方式开坯锻造,研究了CoCrMoW电渣锭锻造保温温度及锻造变形方式对可锻性的影响。试验研究结果表明:CoCrMoW合金电渣锭在1220℃保温1 h后采用整体锻造,锻件的表面质量与内部质量良好;1200℃保温2 h后,采用整体锻造,锻件的表面质量良好,但是内部有缺陷产生;CoCrMoW合金电渣锭在1220℃保温1 h后锻造变形,电渣锭采用分段锻造时表面出现开裂,采用整体锻造时表面质量与内部质量良好;经过开坯后的小规格坯料再继续开坯或锻成品时,分段锻造与整体锻造均可采用。该合金合理的锻造保温温度为1220~1240℃,电渣锭锻造变形方式必须采用整体锻造;小规格锻造方坯变形方式宜采用整体锻造,但也可采用分段锻造。