Wear behaviour of AISI D3 and AISI M3:2 tool steels in a mass production shearing operation

The wear of two tool steels (AISI D3 and AISI M3:2) was compared in a normal production shearing operation by scanning electron microscopy at fixed production intervals.After the wear-in period, in which plastic deformation was observed, abrasive wear occurred by the action of small carbides. Wear was more uniform with AISI M3:2 tool steel than with AISI D3 tool steel and the AISI M3:2 tool produced a better finish of the sheared sheet lips.     

Measurements of wear in nuclear components

Measurements were made of the cobalt released to the primary coolant of light water reactors by wear of cobalt-based alloys used on the wear surfaces of valve end mechanisms. Reasonably accurate wear measurements were possible on reactor components by making replicas of the worn areas and using adjacent unworn areas for the reference. The highest wear rates were measured on feedwater regulator valves used to throttle coolant flow in a boiling water reactor. Wear rates as high as 900 mg dm^?2 month^?1 were recorded. The wear rate of these valves was reduced by a factor of 100 at one plant by substituting AISI 440C stainless steel for the traditional cobaltbased hardfacing. Wear measurements on components from pressurized water reactors showed that in general the wear rates were lower than observed on valve components from boiling water reactors. Typical wear rates on control element drive mechanisms, the largest contributors examined, were of the order of 10 mg dm^?2 month^?1 or less. Wear of gate valves contributed very little cobalt to the primary coolant. Apparently, corrosion causes a larger cobalt contribution than wear does in pressurized water reactors.     

An evaluation of the wear behaviour of a dual-phase low-carbon steel

Wear behaviour of dual-phase AISI 1020 steel was investigated. The steel was austenitized at critical transformation temperature and rapidly quenched. Thus, the structure of the steel consists of martensite and ferrite phases in different proportions. Heat treated samples were subjected to wear with a cylinder-on-cylinder sample configuration under dry sliding conditions. Wear resistance was determined as functions of hardness and proportion of martensite phase, and elongation of the steel. The wear resistance of the dual-phase 1020 steel was also compared with those of hardened and tempered AISI 1040 and 8640 steels. It was indicated that the wear resistance of the test steel decreases with martensite proportions, and increases with martensite hardness and elongation of the steel.     

Wear and corrosion wear of medium carbon steel and 304 stainless steel

Wear and corrosive wear involve mechanical and chemical mechanisms and the combination of these mechanisms often results in significant mutual effects. In this paper, tribological behavior, X-ray peak broadening, and microstructure changes of carbon steel AISI 1045 and stainless steel AISI 304 samples under simultaneous wear and corrosion were investigated and the results were compared with those obtained from dry wear tests. 3.5 wt.% NaCl solution was used as the corrosion agent and a pin-on-disk tribometer was employed to perform wear and corrosive wear tests.X-ray diffraction measurements have shown that by increasing the applied load, the worn surfaces of carbon steel samples reached a constant strain at which fracture and wear occurred. Whereas in 304 stainless steel samples, by increasing the applied load, broadening of X-ray diffraction peaks was decreased.Wear tests of carbon steel and stainless steel samples have shown smaller weight losses and lower friction coefficient in the presence of corrosive environment. Study of worn surfaces suggested that depending on wear environment and applied load, different features of wear mechanisms were involved.     

Wear of AISI 4340 steel under boundary lubrication

Wear tests were conducted using AISI 4340 steel sliding on AISI 01 tool steel under boundary lubrication conditions. The AISI 4340 steel was heat treated to obtain different microstructures and hardness levels. The results indicated that the wear behavior depends on the heat treatment procedure. It was found that hardness alone cannot be used as a measure of wear and that the microstructure and other mechanical properties should also be used. Chemical reaction products containing phosphorus, sulfur and zinc were found on the wear surfaces lubricated with a fully formulated light oil containing zinc dithiophosphates. The chemically reacted film was nonuniform and consisted of patches 1–1500 μm in size. The larger patches were formed on the surface of steel with a pearlite-ferrite microstructure and resulted in a high wear rate. In contrast, the small patches and the thin blue and brown films were formed on the wear surface of tempered martensite steel and produced low wear rates.     

Tribological evaluation of oil pump relief valve coatings compatible with an aluminum oil pump body

Wear can cause automotive relief valves to jam. In order to evaluate and screen candidate coatings for oil pump relief valves for reduction of aluminum pump cylinder bore wear and wear-related sticking, a laboratory reciprocating wear test using production parts has been developed. The coatings on valves include impinged and physical vapor deposited (PVD)-coated molybdenum disulfides, electroplated nickel–phosphorous with polytetrafluoroethylene (Ni–PTFE), electroplated bronze, and electroplated nickel–phosphorous–boron nitride (Ni–P–BN).

The test results showed that the electroplated bronze coating demonstrated the best wear resistance against 380 aluminum pump bores while Ni–PTFE ranked second, PVD-coated MoS₂ third, and Ni–P–BN ranked last. It was observed that the electroplated bronze coating showed only mild oxidative or abrasive wear after 20 h wear test. The Ni–P–BN coating gave the worst wear resistance due to severe abrasive wear, surface scoring, and coating abrasion during the wear test. The major wear mechanisms for valve bore/relief valve can be classified at different levels from mild wear (oxidative wear or surface delamination) to abrasive wear (scoring, scuffing, and ploughing). This paper also reviewed the rooted wear mechanisms of production pump relief valves against aluminum bores based on metallographic observations of worn surfaces after field tests. This tribological investigation of valve coatings has provided insights into the fundamental wear mechanisms which depend on the compatibility of two sliding materials, protective coating composition, hard particle content, and surface interaction. The information will be useful in preventing oil pump relief valves from jamming.     

The effects of work material on tool wear

Wear maps showing the wear behaviour of titanium carbide (TiC)-coated cemented carbide tools during dry turning of various types of steel have been presented in earlier studies. The maps have demonstrated that tool wear rates vary with cutting speeds and feed rates used. They have also shown that there is a range of cutting conditions, called the safety zone, within which tool wear rates are the lowest. This paper further examines, using the wear mapping methodology, the effects of different grades of steel workpieces on the wear of TiC-coated carbide tools. Wear maps constructed for the machining of AISI 1045 and 4340 steels show that flank wear is generally more severe when machining the AISI 4340 grade, especially at high cutting speeds and feed rates. Nevertheless, the contour and location of the safety zone on the wear maps for both grades of steels correspond to that revealed in previous work on general steel grades.     

The Effect of Different Temperatures on Friction and Wear Properties of CFRPEEK against AISI 431 Steel under Water Lubrication

The tribological behavior of 30 vol% carbon fiber–reinforced polyetheretherketone (CFRPEEK) against AISI 431 steel under different temperatures of water lubrication was investigated. Friction and wear tests were carried out on a disc-on-disc contact test apparatus under different operating conditions. The results reveal that the lubricant temperature has a significant effect on the friction and wear properties of CFRPEEK sliding against AISI 431 steel. The average friction coefficient and wear rate of CFRPEEK increase with increasing lubricant temperature. However, the wear rate of AISI 431 steel did not have a positive correlation with the wear rate of CFRPEEK under different temperatures of water lubrication. Moreover, the original and worn surfaces of CFRPEEK and AISI 431 steel were imaged by environmental scanning electron microscopy and optical microscopy, respectively. The main tribological mechanisms of CFRPEEK sliding against AISI 431 steel were adhesive wear, and increasing the temperature of the lubricant could accelerate wear.     

ZrO2/CePO4复合陶瓷钻削试验中刀具磨损机理的研究

制备了ZrO2 /CePO4可加工陶瓷材料 ,采用硬质合金钻头分别进行ZrO2 /CePO4陶瓷和低碳钢的钻削试验。通过刀具磨损量随材料去除量变化的规律来分析材料去除特性 ,通过扫描电子显微镜分析ZrO2 /CePO4陶瓷钻削加工中的刀具磨损形式。试验结果表明 :在加工初始阶段 ,两种材料的刀具磨损量比较接近 ,随着钻削的继续进行 ,加工ZrO2 /CePO4陶瓷的刀具磨损量明显高于加工低碳钢的刀具磨损量 ;加工ZrO2 /CePO4陶瓷时 ,刀具的磨损形态包括主后刀面磨损、副后刀面磨损和横刃磨损 ,其中钻头副后刀面磨损现象是ZrO2 /CePO4材料加工的一个显著特征 ,与金属材料的加工存在差异 ;刀具磨损的主要原因是磨料磨损、粘结磨损和氧化磨损。     

The corrosion wear behaviour of selected stainless steels in potash brine

Tests were conducted at 25 and 85 °C to evaluate the corrosion wear resistance of selected stainless steels in potash brine using a reciprocating motion wear apparatus. Four materials were tested: Ferralium 255 (UNS S32550), AL6XN (UNS N08367), 254SMO (UNS S31254) and AISI 1018 (UNS G10180) for comparative purposes. The evaluation methods employed included weight loss analysis, optical microscopy and scanning electron microscopy (SEM). The results show that Ferralium 255 has superior corrosion wear resistance in potash brine environment compared to AISI 1018 plain-carbon steel and the other stainless steels tested. Wear surface analysis using SEM shows evidence of brittle fracture damage, which is attributed to the presence of Cl⁻.     

尼龙6/蒙脱土纳米复合材料的摩擦学特性及磨损机理

用熔融插层法制备了不同蒙脱土含量的尼龙6/蒙脱土纳米复合材料,并与45钢进行了环块对磨试验.结果表明：该材料与45钢对磨的摩擦因数随有机蒙脱土含量的增加而减小;纯尼龙6和2%有机蒙脱土复合材料的磨损属于机械和粘着磨损;4%有机蒙脱土复合材料的磨损属于疲劳磨损;6%和8%有机蒙脱土复合材料的磨损以机械磨损为主;10%蒙脱土复合材料的磨损主要以疲劳磨损为主.     

Study on transition between fretting and reciprocating sliding wear

An experimental investigation was conducted to find the associated changes in characteristics of wear before and after the transition between fretting and reciprocating sliding wear. A set of experiments were carried out using a AISI 52100 steel ball rubbing against a plate specimen made from the same steel under dry condition. Wear coefficient, wear volume, coefficient of friction, profile of the scars and wear debris were analyzed. The results displayed that there were significant differences in wear coefficient, wear volume, profile of the wear scars and wear debris before and after the transition. Wear coefficient and wear volume at a constant sliding distance were found to be the most appropriate for identifying the transition amplitude between fretting and reciprocating sliding wear.     

车辆机械零件的磨损与预防

磨损是车辆机械零件的主要的失效形式,按磨损机理可分为粘着磨损、磨料磨损、疲劳磨损、腐蚀磨损、气蚀和微动磨损等,通过分析车辆机械零件的磨损机理,采取合理的预防措施,可有效地提高车辆机械零件的使用寿命。     

Damage of Stainless Steel Components by Olive Paste

Failure of equipment for processing olives interrupted oil production after only 3 weeks in service. Macroscopic and microscopic analyses were used in the present investigation to analyze damaged surfaces. Observations and data suggest that failure was induced via tribocorrosion with a predominance of mechanical damage. This damage is attributed to abrasive wear combined with corrosion of AISI 304L stainless steel in olive paste (seed particles and pulp) mixed with tap water. Microscopic observations revealed fracture and localized plastic deformation in the damaged area along with a tribologically transformed structure and work-hardened surfaces. The tribological behavior of AISI 304L was determined using a pin-on-disc tribometer, and these results were compared to damage on the olive processing equipment. The steel was sensitive to tribo-oxidation, mostly due to abrasion by seeds and steel wear particles, and somewhat due to corrosion reactions with the environment.     

Influence of sliding frequency on reciprocating wear of mold steel with different microstructures

The wear resistance of a low alloy plastic mold steel has been studied under pin-on-flat reciprocating configuration against AISI 52100 steel pins, under variable sliding frequency. The as-received material (HTO; 33 HRC) was heat treated under variable conditions to obtain different microstructures and hardness (HT1, quenched 880 °C, 58 HRC; HT2, tempered 550 °C, 43.4 HRC; HT3, tempered 300 °C, 52 HRC; HT4, annealed, 26 HRC). Under low sliding frequency (1 Hz), no significant differences in the wear resistance of the different materials are observed. Only at 8 Hz, a relationship between hardness and wear resistance is found. The softer annealed material HT4 shows an increasing wear rate under increasing frequency, while the quenched steel HT1 gives the lowest wear at the highest frequency. Wear mechanisms have been studied from SEM and EDS observations. Only HT4 shows a transition from the abrasive and oxidative wear mechanisms found in all cases to an adhesive wear mechanism under the highest frequency.     

Nucleation and formation of oxide film with the magnetic field on dry sliding contact of ferromagnetic steel

The nucleation and formation of oxide film in unidirectional dry sliding contact has been studied in a vacuum chamber with and without the application of a magnetic field in the intention of identifying the role of magnetic intensity on the oxidation wear. The wear tests of the steel AISI 1045/steel AISI 1045 couple are investigated on a pin‐disc configuration under three various gas environments: in ambient air, under oxygen at 10⁵ Pa and in vacuum at 5.10⁻⁵ Pa. The formation of oxide layer strongly depends on oxygen partial pressure and magnetic field intensity. These took the form of protective raised ‘islands’ of compacted debris which is developed gradually but rapidly increased as the oxygen partial pressure is increased and which could persist for extended periods during subsequent evacuation. Evidence from various experimental techniques indicates that the compacted debris is a mixture of iron oxides in the form of oxide‐covered particles, although the depth of oxide film has not yet been fully elucidated. Copyright © 2010 John Wiley & Sons, Ltd.     

高压磨料水喷嘴磨损实验研究

本文采用硬质合金和陶瓷材料制成喷嘴．在高压水设备上进行了磨损实验研究。结果表明，影响其耐磨性主要因素是喷嘴材料、表面硬度及高压磨料水工艺参数。同时采扫描电镜对喷嘴磨损表面进行了分析。     

Wear of cast chromium steels with TiC reinforcement

Wear resistance of a series of new titanium carbide reinforced cast chromium steels was investigated under various wear conditions. The steels which were melted in a vacuum induction furnace contained 12 Cr, 3–5 Ti, 1–2 C in weight percent. Microstructure of these materials was characterized using scanning electron microscopy, light optical microscopy, and X-ray diffraction. Microstructure of steels consisted of TiC phase dispersed in a martensitic matrix. High-stress and low-stress abrasion tests, and an erosion test, were utilized to understand the wear behavior of these materials under different environments. The steels were tested in as-cast and heat treated conditions. Wear rates of the cast Cr/TiC steels were compared to those of an AISI type 440C steel and P/M composites reinforced with TiC.     

Some observations on the wear of aluminium rubbing on steel

Wear tests on high pressure counterformal contacts between an aluminium alloy and a low carbon steel produced different regimes of wear depending on specimen geometry and whether the aluminium specimen was disposed as the stationary specimen or the counterface. Oxidative wear was maintained at high levels of unit load (200 MN m^?2) provided that the surfaces were not subjected to large-scale plastic flow. Wear rates were greatly increased when the amount of aluminium transfer onto the steel surface was substantial, and under these circumstances evidence of back transfer was observed.     

Fretting wear behaviors of steel wires under friction-increasing grease conditions

Fretting wear tests were performed on the self-made fretting wear rig to investigate fretting wear behaviors of steel wires under friction-increasing grease conditions. The results demonstrated that the fretting regimes were dependent on displacement amplitudes and normal loads. The friction coefficient exhibited different variation trends in different fretting regimes. Friction-increasing grease changed the fretting running behavior and had a very good wear resistance for steel wires. Wear was slight in partial slip regime. Mixed regime was characterized by plastic deformation, fatigue cracks and abrasive wear. Slip regime presented main damage mechanisms of abrasive wear, fatigue wear and oxidation.