磁化处理提高工夹刀量模具使用寿命

磁化处理是一种具有强化性能、改善材料组织等多种作用的新技术。图1所示为最简单的一种磁化装置。在电磁场的作用下,被处理工具(或零件)的分子结构发生了物理化学变化,从而能起到改善组织,消除应力,提高强度和耐磨性等的功能。无论是用碳钢、合金钢、不锈钢、工具钢、铸铁、青铜等金属材料制     

多元微合金化稀土中锰白口铸铁磨球的研究和应用

本文研究了多元微合金化对稀土中锰白口铸铁显微组织、机械性能和抗磨性的影响。实验结果表明:稀土中锰白口铸铁加入多元微合金后,组织细化,韧性和耐磨性提高。生产验证表明:含多元微合金的稀土中锰白口铸铁磨球硬度均匀,球耗量低(60～80克/吨水泥),耐磨性是40Cr锻钢球的2～3倍。     

灰口铸铁等离子表面硬化处理后的组织与性能

利用常压等离子相变硬化设备对灰口铸铁进行了表面相变硬化处理,处理后铸铁熔凝层的显微组织为初生奥氏体＋莱氏体,固态相变硬化层的组织为隐针马氏体＋残余奥氏体＋片状石墨和少量磷共晶,铸铁的表面硬度明显高于基体硬度,并明显提高了灰口铸铁材料的耐磨性和使用寿命。     

改变基体组织热处理的理论及工艺

探讨了改变集体组织热处理的理论及工艺.通过时友铸铁和球墨铸铁的正火处理及淬火和回火的工艺处理,使基体组织的强度和耐磨性得到了增强,铸件的各种性能(耐磨性、硬度等)得到了提高,因此,改变基体组织热处理是铸铁热处理主要方法之一.     

马氏体球墨铸铁腐蚀磨损特性研究

对马氏体球墨铸铁在不同pH值石英砂浆中的静载三体腐蚀磨损特性进行了试验研究,并与铬白口铸铁进行了对比。结果表明：无论在静栽三体磨料磨损或静载三体腐蚀磨损中,马氏体球置铸铁均优于低铬白口铸铁。适当提高含硅量,有利于提高腐蚀耐磨损性,而且在酸性砂浆中效果较明显。     

高铬铸铁衬板的耐磨性研究

分析3种不同形态碳化物与基体组织分布的高铬铸铁衬板,在MM-W1A型摩擦磨损试验机上与沙石进行耐磨性对比。结果表明:碳化物形态分布对高铬铸铁耐磨性有直接的影响,块状或短杆状且分布均匀的碳化物对提高材料的耐磨性有利,网状或长针状碳化物对耐磨性不利。     

提高钨合金铸铁磨球使用性能的研究

以我们新开发的钨合金铸铁磨球为基础，探讨了采用稀土变质处理以提高其使用性能的可靠性。研究结果表明，钨合金铸铁经适量稀土变质处理后，共晶碳化物内网状分布变成断网状分布，磨球冲击韧性显著提高，硬度略有上升，耐磨性明显改善，冲击疲劳寿命显著提高，磨球各项指标达到了甚至超过了高铬铸铁球的水平。     

深冷处理对高铬白口铸铁组织与性能的影响

将空淬过的高铬白口铸铁经-196℃深冷处理后在不同温度下回火,研究了深冷处理对该铸铁硬度、冲击韧度、滑动磨损、滚筒式磨损和金相组织等的影响。结果表明：经深冷处理后,其硬度有较大幅度提高,但冲击韧度略有下降;深冷处理后再经250℃回火,可以获得较好的硬度和韧性的配合;经深冷处理后再回火的硬度峰值比未经深冷处理的提前了约100℃;深冷处理对耐磨性影响不明显。     

稀土低镍铬合金铸铁的耐烧碱腐蚀性能研究

用电化学和动态失重法测定稀土低镍铬铸铁在高温烧碱中的阳极极化曲线和腐蚀速度;用显微镜和扫描电镜观察显微组织和腐蚀形貌。结果表明,加入稀土细化低镍铬铸铁组织并改变石菜态,提高耐高温碱腐蚀性能,其中ＤＮＪ３（０．０４６％ＲＥ）腐蚀速率最小,维钝电流低,钝化区间长,是优良的耐碱蚀材料。     

带磁切削机理及磁化处理的推广应用

通过对带磁切削的机理研究，发现磁化处理引起的磁致伸缩强化现象能够提高金属材料的强度、硬度及抗粘着磨损的能力，结合磨损的四种基本类型以及磁化处理的效果和可行性，认为磁化处理将是提高金属材料耐磨性的一种简单有效的新方法．     

一种新型船用柴油机油的研制

根据船用柴油机油的性能要求,通过开展基础油及各功能添加剂等对油品抗水、分水性能的影响研究,以及清净分散剂、抗氧抗磨剂等添加剂对油品高温清净性、烟炱分散性、抗磨损性及抗氧抗腐蚀性的影响研究,提出一种新型船用柴油机油配方方案。综合评定试验结果表明,研制的船用柴油机油具有优异的理化性能和良好的分散性、抗氧抗腐蚀性、抗磨性能和清净性能,并通过了FZG齿轮试验机试验和发动机台架试验。     

24Cr高铬铸铁三体腐蚀磨损过程中腐蚀与磨损的交互作用

本文研究了24Cr高铬铸铁在弱酸性介质条件下,三体腐蚀磨损过程中腐蚀与磨损的交互作用,初步建立了解析模型。探讨了基体组织,含碳量与稀土元素在腐蚀与磨损交互作用过程中的作用。     

Microstructure and performance of multi-dimensional WC-CoCr coating sprayed by HVOF

WC-based coatings deposited by high velocity oxy-fuel (HVOF) spraying have been widely used in many industrial fields, where mechanical components are subjected to severe abrasive wear. Much attention has been especially paid to nanostructured and multimodal WC-based coatings due to their excellent abrasive wear resistance. In this study, a new kind of multi-dimensional WC-10Co4Cr coating, composed of nano, submicron, micron WC particles and CoCr alloy, was developed by HVOF. The microstructure, porosity, microhardness, fracture toughness, and electrochemical properties of the coating were investigated in comparison with nanostructured WC-10Co4Cr coating deposited by HVOF. Abrasive wear resistance of both WC-10Co4Cr coatings was evaluated on wet sand rubber wheel abrasion tester. The results show that the multi-dimensional coating possesses low porosity (0.31 ± 0.09%), excellent microhardness (1126 ± 115 HV_0.3), fracture toughness (4.66 ± 0.51 MPa m^1/2), and outstanding electrochemical properties. Moreover, the multi-dimensional coating demonstrates approximately 36% wet abrasive resistance enhancement than the nanostructured coating. The superior abrasive wear resistance originates from the coating’s multi-dimensional structure and excellent mechanical and electrochemical properties.     

New Experimental Rig to Investigate Abrasive–Corrosive Characteristics of Metals in Aqueous Media

A new tribometer to investigate a conjoint effect of three-body abrasion and corrosion has been developed. In this design, a flat wear sample is loaded against a rotating cylindrical disc counterface and the abrasive slurry is delivered to the contact interface. Capabilities of the newly developed tribometer have been assessed through conducting abrasion–corrosion tests involving simultaneous electrochemical measurements. In this work, the stability of the passive layer on stainless steel under three-body abrasive wear in a near neutral electrolyte was investigated using potentiodynamic polarization tests. 316L Stainless Steel wear samples were abraded by coarse garnet particles in an aerated sodium sulphate electrolyte. The effects of load and speed on the polarization curves and passivity of 316L steel were determined. It was found that under abrasion–corrosion conditions 316L steel became more thermodynamically active and the passive corrosion rate has increased. Increasing the contact load resulted in a small increase in the passive corrosion current, while increasing the rotating speed had the opposite effect of decreasing the current. Linear polarization resistance method was used to analyse corrosion current changes with time during abrasion–corrosion testing. The existence of three distinct stages was explained by the third-body effect on the corrosion potential and current. First stage was revealed by continuous decrease of corrosion potential. Then, the potential reached a plateau for the second and third stages. In the first and second stages, particle constraint in the contact zone plays the major role and a linear rise in corrosion current with time has been recorded. After a certain amount of surface roughening, no further increase in particles entrapment is expected. Therefore, in the third stage steady-state corrosion current values are anticipated. The rig developed can also be used to simulate two-body abrasion–corrosion. The capabilities of the new rig have been compared against other experimental set-ups used in studies of combined abrasion–corrosion behaviour.     

基于FEA的螺旋式氮化硅陶瓷柱塞偶件精密加工技术研究

陶瓷柱塞偶件由于其耐腐蚀、耐磨损等优异性能受到发动机设计人员的青睐,但由于其工艺复杂、加工困难等原因严重束缚了其应用。本文在分析12150L柴油机柱塞偶件在额定工况下材料为氮化硅时应力和位移变化规律的基础上,着重研究了氮化硅陶瓷柱塞偶件的精密加工技术。针对较难加工的螺旋线和出油槽等难加工部位,设计并研制了专用工装夹具,并取得了满意的加工效果。台架试验结果表明:在相同试验条件下,与金属相比其磨损量降低了82%~91%,使用寿命提高了8~11倍。     

Abrasion–Corrosion Behaviors of Steel–Steel Contact in Seawater Containing Abrasive Particles

Materials working in slurries containing seawater and abrasive particles degrade gradually because of the synergic effects of mechanical wear and electrochemical corrosion. In this study, the abrasion–corrosion behaviors of a steel–steel tribopair in an environment with artificial seawater and SiO₂/Al₂O₃ particles were investigated. Corrosion is responsible for surface degradation at low concentrations of SiO₂ particles, whereas abrasion is the primary cause for steel damage at high SiO₂ concentrations. When Al₂O₃ particles were used, abrasion was found to be the dominant factor for material loss at all concentrations. Results from this study indicate that at low concentrations of hard particles, abrasion–corrosion behavior is determined by the properties of particles.     

Abrasion properties of forged fibre-reinforcedaluminium

The effects of forging on the abrasion properties of fibre-reinforced aluminium have been investigated. Metal matrixcomposites with 20 or 30 vol% short Al₂O₃-fibres in an aluminium alloy matrix were forged and evaluatedregarding the wear resistance and friction in a pin-on-cylinder abrasion setup. The microstructure and wear mechanisms have beenstudied with scanning electron microscopy. It has been shownthat the dependence on fibre content and forging is differentdepending on the type of abrasion. The wear resistance of thecomposites increased with fibre content and decreased due to forging, in milder abrasion. In more severe abrasion there wasa tendency towards the opposite behaviour: decreased wearresistance with fibre content and increased with forging. Anincreased amount of fibre reinforcement decreased thecoefficient of friction.     

Wear of low temperature nitrided steels under different wear processes

A programme of tests has been carried out to assess the wear resistance of three low temperature nitriding treatments when compared with the untreatedv steel and a standard cyanide case-hardening treatment, under conditions of scuffing, abrasion, fretting and corrosion. The main conclusion is that low temperature nitriding is most suited to applications where scuffing and corrosion are the main wear mechanisms and that the resistance to abrasion and fretting is poorer in general than that of traditional case-hardening. Therefore, care should be taken in assessing the wear process in any application in which these treatments are used. Reference is also made to the wear mechanisms in the different tests.     

不同石墨烯添加量下MoS2基复合涂层的摩擦磨损及耐腐蚀性能

为改善MoS2基固体润滑涂层的摩擦磨损性能和耐蚀性能,制备了不同石墨烯（GE）添加量的MoS2复合涂层,利用HSR-2M摩擦磨损试验机测试了复合涂层的摩擦磨损性能,并分析了其磨损机理,通过极化曲线、交流阻抗谱（EIS）研究了涂层在3.5%NaCl溶液中的电化学腐蚀行为。试验结果表明,0.8-GE/MoS2复合涂层的摩擦磨损和耐腐蚀性能最优,其平均摩擦因数和磨损率分别为0.232和2.379×10-13 m3/(N·m),较未添加石墨烯的MoS2涂层分别降低了49.56%和43%,腐蚀速率（1.96×10-8 A/cm2）较纯MoS2涂层（5.54×10-6 A/cm2）降低了近2个数量级。石墨烯的二维片状结构具有良好的自润滑性能,在涂层中均匀分布时能有效阻隔腐蚀介质的渗透,因此,石墨烯的添加提高了MoS2基复合涂层的摩擦学性能和耐腐蚀性能,石墨烯的最优添加量为0.8%（质量分数）。     

The effect of carbon structure on in-situ protection for granular thin film media

The in-situ nano scale protection concept has been proposed recently based on granular thin film media. In this study, two series of samples with structure of glass substrate/NiAl/Cr/(CoCrPt/C)₁₂/C prepared by facing target sputtering (FTS) and normal DC sputtering (DCS) were examined. FTS samples were shown to possess superior corrosion resistance than the DCS samples by accelerated environmental test and electrochemical technique developed from linear polarization resistance (LPR) measurement. Carbon structure was characterized by Raman spectroscopy. The corroded samples were observed by optical microscopy and the depth distribution of corrosion products was characterized by TOF-SIMS. We conclude that the carbon structure plays the most important role in in-situ nano scale protection for granular thin film media. We also discussed the effect of different structure carbon in inter-layer and top-layer on corrosion resistance of this kind of media.