材料在铝液中熔蚀-磨损行为的研究进展

Research Progress on Corrosion-Wear Behavior of Materials in Molten Aluminum

在冶金、化工、航空航天及汽车等领域,高温腐蚀性环境中承受动载的关键零部件往往因为腐蚀-磨损的作用而失效,从而造成巨大的经济损失。当前,对于腐蚀-磨损的研究多集中于材料在腐蚀性气体、溶液或颗粒冲刷条件下的加速流失,而对材料在高温金属熔体中的熔蚀-磨损失效行为研究鲜有报道,对材料在高温金属熔体中腐蚀失效及摩擦磨损失效的交互作用尚不明确。铝及其合金产量居有色金属材料之首,被广泛应用于建筑、交通、能源、航空航天、电子等领域。然而铝熔体是腐蚀性最强的金属液之一,铝工业如冶金、成形及热浸镀等生产过程中的一些关键零部件往往因熔蚀-磨损而失效破坏。目前大量使用的仍是高合金的耐磨类材料如模具钢,材料价格昂贵、使用寿命很短,只能依靠频繁更换部件来维持生产。因此迫切需要开发耐铝液熔蚀-磨损新材料,满足铝工业生产应用的需求。然而,由于高温金属熔体这一腐蚀介质的特殊性,对材料高温熔蚀-磨损行为的研究鲜有报道。这一方面是由于缺乏专用的设备对材料的熔蚀-磨损行为进行测试表征,另一方面则是由于腐蚀界面存在复杂的冶金物理化学反应,而关于熔蚀和磨损行为的交互作用机理尚不明确。目前对于材料在铝液中熔蚀-磨损行为的研究较少,部分研究主要集中于铝合金液态成形过程中模具的冲蚀-磨损行为及材料替代,材料在铝液中的熔蚀-磨损机理研究则尚处于空白。近两年,在开发新型高温金属熔体腐蚀-磨损试验系统的基础上,学者实现了对材料在高温金属铝液中熔蚀-磨损行为的研究,并进行了大量的材料筛选。研究表明,常用的金属材料在铝液中的熔蚀-磨损行为主要受界面金属间化合物的生成速度、性质及其与基体界面的结合情况的影响。材料因熔蚀-磨损导致的流失远大于纯腐蚀与纯磨损导致的材料流失之和,说明材料在铝液中的熔蚀-磨损失效并不是腐蚀和磨损行为的简单叠加,其主要失效机理在于熔蚀和磨损的交互作用。对常用的H13钢材料而言,其在典型工况下的熔蚀-磨损交互作用率达90%以上。在材料开发方面,目前大多依靠单一的腐蚀试验以及高温摩擦磨损试验来收集数据,对耐铝液熔蚀-磨损材料的研究也主要集中在铁基合金组织调控、难熔金属应用以及表面处理技术这三个方面。近年来发展起来的金属间化合物基复合材料也为耐铝液熔蚀-磨损新材料的开发开辟了新的思路。本文简要介绍了材料在铝液中的熔蚀-磨损失效行为,指出熔蚀与磨损的交互作用是导致材料或零件失效的关键原因,在此基础上提出了对耐铝液熔蚀-磨损材料的性能要求。基于对国内外耐铝液熔蚀-磨损材料研究进展的综述,提出了耐铝液熔蚀-磨损材料未来的发展方向和研究重点。

I n the field of metallurgical,chemical,aerospace and automotive,corrosion-wear damage to the key components used in high temperature corrosive environment under dynamic loading often results in tremendous economic losses.Many researches have focused on the accelerated degradation of materials in corrosive gas,solution or particle erosion conditions.However,the corrosion-wear behavior of materials in high temperature metal melt has been rarely reported,and the synergy mechanism between corrosion and wear is still inexplicit.Aluminum and its alloys are widely used in buildings,transportation,energy,aerospace,electronics and other areas.However,aluminum melt is one of the most corrosive metallic fluids.Some key parts in the production process of aluminum industry,such as metallurgy,forming and hot dip,are often damaged by corrosion and wear.At present,a large number of wear-resisting materials of high alloy,such as die steel,are still used,but they are costly and have a short service life.Production can only be maintained by frequent replacement of parts.Therefore,it is urgent to develop new liquid-aluminum-resistant corrosion and wear materials to meet the needs of aluminum industrial production and application.However,due to the particularity of high temperature metal melt as a corrosive medium,few studies have been reported on the corrosion behavior of high temperature metal melt.On the one hand,due to the lack of special equipment to test and characterize the corrosion and wear behaviors of materials.On the other hand,due to the complex metallurgical physical and chemical reactions at the corrosion interface,the interaction mechanism between corrosion and wear behaviors is still unclear.At present,for the studies of the material corrosion behavior and mechanism in the liquid aluminum are more,while that of the material corrosion and wear behavior in the liquid aluminum are few.Some researches focused on the erosion and wear behavior in aluminum alloy molten shaping process and material substitution.The study of material corrosion-wear mechanism in liquid aluminum is still in the blank.In the past two years,on the basis of developing a new corrosion and wear of high-temperature metal melt test system,the corrosion and wear behavior of materials in high-temperature aluminum liquid has been studied,and a large number of materials have been screened.It is found that the corrosion and wear resistance of the commonly used metal materials is depend on the formation rate and characterization of intermetallic compound layer,as well as the combination between the substrate and intermetallic zone.The amount of material erosion-wear loss is much larger than the sum of pure corrosion and pure wear material loss indicates that the corrosion-wear failure of material in aluminum liquid is not a simple superposition of corrosion and wear behavior,and the main failure mechanism lies in the synergy mechanism between corrosion and wear.For the commonly used H13 steel materials,the ratio of corrosion-wear interaction under typical working conditions is more than 90%.In the aspect of material development,data collecting is relied on single corrosion test or high temperature friction and wear test.The development of materials with excellent corrosion-wear resistance in molten aluminum mainly focus on three aspects:microstructure regulation of ferrous alloy,application of refractory metals and surface treatment technology.Intermetallic matrix composites developed in recent years have also opened up new ideas for the development of new materials with excellent corrosion-wear resistance in molten aluminum.This paper briefly introduces the corrosion and wear failure behavior of materials in aluminum liquid,and points out that the interaction between corrosion and wear is the key reason for the failure of materials or parts.On this basis,the performance requirements of materials with excellent corrosion-wear resistance in molten aluminum are put forward.Based on the review of the research progress,the paper puts forward the future development direction and research focus of these new materials.