低合金耐磨铸钢楔齿滚刀的性能及热处理

测定了钻井楔齿滚刀用新型低合金耐磨铸钢的物理及力学性能，研究了钢的性能与回火温度的关系，以及钢的耐磨性与硬度和断裂韧性的关系。结果表明，该钢具有较好的淬透性及堆焊性，经900～950℃加热淬火及200～250℃回火后，具有高的强韧性及高耐磨性。用该钢制造的钻井楔齿滚刀的寿命显著提高，可实现以锗代锻，明显降低了滚刀的生产成本。     

（Fe—Ni）—MoS2自润滑复合镀层的制备及性能研究

在酸性氯化物电解液中进行了ＭｏＳ２微粒与铁、镍共沉积的试验，确定了制备（Ｆｅ－Ｎｉ）－ＭｏＳ２复合镀层的最佳工艺参数。对所得到的复合镀层的摩擦磨损特性进行了研究。结果表明：铁镍合金镀层中弥散分布着６．４１ｗｔ％的ＭｏＳ２微粒后，与Ｆｅ－Ｎｉ合金镀层，４５＾＃淬火钢和球墨铸铁相比，其摩擦系数和损率显著降低，镀层的摩擦磨损性能得到改善。     

新型非密封滑动轴承牙轮钻头的试验研究

密封滑动轴承牙轮钻头的密封圈工作条件恶劣,极易损坏;密封圈占据了轴颈的一部分空间,使钻头承载能力减小,这些都降低了钻头的使用寿命。通过滑动轴承失效原因的分析,提出非密封滑动轴承牙轮钻头的轴承表面应采用硬度大、热稳定性好的材料,轴承摩擦副应采用硬-硬配对方式。经过对WC-Co类硬质合金材料力学性能和摩擦学性能分析,用新的轴承结构解决了硬质合金脆性问题,并研制出新型非密封硬质合金滑动轴承牙轮钻头。室内试验表明,硬质合金摩擦副具有良好的抗磨粒磨损能力,可用于牙轮钻头非密封滑动轴承的滑动表面。现场初步试验证明,新型非密封硬质合金滑动轴承牙轮钻头具有良好的应用前景,是发展高速滑动轴承牙轮钻头和小尺寸滑动轴承牙轮钻头的有效途径。     

Experimental Study on Surface Deterioration of Hot RollingMill Rolls under Near Service Conditions

ＥｘｐｅｒｉｍｅｎｔａｌＳｔｕｄｙｏｎＳｕｒｆａｃｅＤｅｔｅｒｉｏｒａｔｉｏｎｏｆＨｏｔＲｏｌｌｉｎｇＭｉｌｌＲｏｌｌｓｕｎｄｅｒＮｅａｒＳｅｒｖｉｃｅＣｏｎｄｉｔｉｏｎｓＣｕｉＰｅｉｙｏｎｇＡｂｓｔｒａｃｔ：Ｗｉｔｈｓｐｅｃｉａｌｌｙｄｅｓｉｇｎｅ...     

Stochastic approach to the modeling and optimization of thermal spray coating formation

Application of the stochastic process theory is proposed for the modeling and optimization of the thermal spray process (TSP). The advantages of the approach suggested are illustrated by estimation of the“integral” thermal conditions of TSP coating formation, as well as the formation characteristics of the first monolayer coating. Modeling results are in reasonable agreement with bond strength test data for the plasma-, arc-, and flame-spray processes as well as wear resistance data for arc-sprayed steel coatings.     

我国循环流化床锅炉存在问题及试验研究

章通过对国内电厂循环流化床锅炉进行试验分析研究,提出流化床内颗粒群运动的多态性、氧气使用效率的概念和磨损可控原理,分析了CFB锅炉存在的主要问题,如煤粒径分布不合理、给煤点少、飞灰含碳量高、风机选型偏大等。重点对磨损进行了研究,采用让管技术可有效解决磨损问题,对CFB锅炉的设计、制造和运行具有一定的参考价值。最后阐述了CFB锅炉在设计、运行和改进方面需要系统总结的观点,指出今后开展工作的研究方向。     

Nano-Wear Mechanism for Ultra-High Molecular Weight Polyethylene (UHMWPE) Sliding Against a Model Hard Asperity

This paper investigates the mechanism of wear-particle generation when a single asperity is passed over the surface of UHMWPE. A single asperity is modelled using a conical diamond-tip indenter attached to a nano-scratch tester. Scratches are produced by passing the indenter over the surface of the polymer in a single pass and multiple passes on a single track or on orthogonally intersecting tracks. The debris-generation process, as observed in the nano-scratch test, is complex and depends upon the direction of scratches. It is found that the rate of wear-debris generation is much higher when two consecutive scratches orthogonally intersect each other compared to when the scratches are made on the same track. Wall formation was observed between orthogonally intersecting scratches, and it is believed that this is central to the low-cycle wear mechanism in these systems.     

Tribological properties and mechanisms of sulfide layer prepared by glow discharge

Sulfide layers, with porous and uneven surface and formed randomly by nano-grains, were prepared on the surface of AISI 1045 steel by low-temperature ion sulfuration. The tribological properties, such as friction-reduction, wear-resistance and anti-scuffing of the sulfide layers were investigated systematically on a ball-on-disc tester of model QP-100 under oil lubrication. The results showed that the tribological properties of sulfide layers were superior to that of the unsulfurized ones. AFM and SEM+EDX were used to examine the morphologies and compositions of surface, cross-section and wear scars. XPS was utilized to detect the valence states of boundary. XRD was employed to analyze the phase structure.     

Materials for dry running air motors

Systems analysis, pin-on-disc testing, and motor tests have been used in an investigation of materials for oil-free operation of air motors. The performance achieved with carbon fibre reinforced composites (cfc) running against an Al₂O₃ ceramic and polyimide-amide against a chemically deposite nickel coating suggests that the attainable blade life in dry running motors could match the maintenance intervals of oil-lubricated motors     

High stress abrasive wear behavior of sillimanite-reinforced Al-alloy matrix composite: A factorial design approach

An attempt has been made to explore the possibility of using a natural mineral, namely sillimanite, as dispersoid for synthesizing aluminum alloy composite by solidification technique. The abrasive wear behavior of this composite has been studied through factorial design of experiments. The wear behavior of the composite (Y _composite) and the alloy (Y _alloy) is expressed in terms of the coded values of different experimental parameters like applied load (x ₁), abrasive size (x ₂), and sliding distance (x ₃) by the following linear regression equations: