Cr26MoWVTiRE合金铸铁溜槽衬板开发与应用

针对钢铁企业高炉布料溜槽衬板所处的恶劣作业环境，研究开发出具有一定耐高温、耐腐蚀性的Cr26MoWVTiRE高铬合金铸铁材料。在经1020-1050℃淬火＋320--520℃回火，材料的硬度达到HRC60-62，冲击韧度αK〉5J／cm2。Mo、W合金和V、Ti等强碳化物元素的复合加入，提高了溜槽衬板的硬韧性、红硬性和高耐磨性，衬板实际使用寿命超过18个月。与镶铸硬质合金溜槽衬板相比，该衬板具有生产工艺简单、成本低、性价比高等特点，有一定推广应用价值。

Study on the new materials for fiberboard refiner plate of defibrator

Defibrator is a very important machine in the wood industry for producing fiberboard. The refiner plates are the key parts of defibrator that directly act with the wood, and broken easily. The working life of the refiner plates is of significance to the wood industry. It may affect refining quality, production efficiency, and power consumption. In this paper, the abrasion resistance of the refiner plate made of different materials, the stainless steels and high chromium cast irons, were tested and compared. The results showed that abrasion resistance of refiner plate made of high chromium cast irons was better than that of the stainless steel materials. Although the two kinds of materials have the same compositions, their abrasion resistances have ap-parent difference. The main reason is that the material microstructures have very important effects on their performance. The refiner plates made of developed high chromium cast irons don抰 demand the complex heat treatment. This can simplify the producing process, save the cost of production, decrease labor strength, and increase the production efficiency.

小井眼PDC钻头+螺杆钻具提速技术研究

采取小井眼钻井技术是减少泥浆用量、降低废弃物和减少固井成本的有效途径,但由于小井眼钻井环形空间小、泥浆排量小,导致钻头泥包、小螺杆钻具输出扭矩低等问题,在加上小尺寸PDC钻头定向工具面不稳、螺杆钻具防托压效果不好,使其机械钻速慢、使用寿命低。针对小井眼施工及工况特点,以PDC钻头的防泥包设计、螺杆钻具的防托压设计、小尺寸PDC钻头和螺杆钻具的高攻击性、高造斜、高抗磨等个性化设计为基础,形成了一套小井眼PDC钻头+螺杆钻具优化配置提速技术,达到提高机械钻速、减少起下钻次数、缩短钻井周期、降低钻井成本的目的。

Mechanism of high pressure roll grinding on compression strength of oxidized hematite pellets

The mechanism of high pressure roll grinding on improvement of compression strength of oxidized hematite pellets was researched by considering their roasting properties. The results indicate that oxidized hematite pellets require higher preheating temperature and longer preheating time to attain required compression strength of pellets compared with the common magnetite oxidized pellets. It is found that when the hematite concentrates are pretreated by high pressure roll grinding （HPRG）, the compression strengths of preheated and roasted oxidized hematite pellets get improved even with lower preheating and roasting temperatures and shorter preheating and roasting time. The mechanism for HPRG to improve roasting properties of oxidized pellets were investigated and the cause mainly lies in the increase of micro-sized particles and the decrease of dispersion degree for hematite concentrates, which promotes the hematite concentrate particles to be compacted, the solid-phase crystallization, and finally the formation of Fe203 bonding bridges during subsequent high temperature roasting process.

Effect of nano-size nickel particles on wear resistance and high temperature oxidation resistance of ultrafine ceramic coating

In order to improve the wear resistance and high temperature oxidation resistance of titanium and titanium alloy, the high temperature ultra fine ceramic coating containing nano-size nickel particles was prepared by flow coat method on the surface of industrially pure titanium TB1-0. The effects of nano-size nickel particles on the wear resistance and high temperature oxidation resistance of coating substrate system were investigated through oxidation kinetics experiment and wear resistance test. The morphologies of the specimens were examined by means of optical microscopy, scanning electron microscopy and X-ray diffraction. The results show that the high temperature ultra fine ceramic coating has notable protection effect on industrially pure titanium TB1-0 from oxidation. The oxidation and wear resistance properties of the coating can be effectively improved by adding nano-size nickel particles. The oxidative mass gain of the specimen decreases from 11.33 mg·cm-2 to 5.25 mg·cm-2 and the friction coefficient decreases from 1.1 to 0.6 by adding nano-size nickel particles, and the coating containing 10% （mass fraction） nano-size nickel shows the optimum properties.

Tribological properties of Fe(Cr)-B alloys at high temperature

This work is aimed to study the effect of boron on wear resistance of Fe-Cr-B alloys containing different boron contents(0 wt%,5 wt%,7 wt%and 9 wt%)from room temperature(RT)to 800°C in order to explore their applications as high-temperature wear resistant mechanical parts.Additionally,the wear mechanism of alloys is evaluated.The tribological properties of alloys are systematically studied by using a ball-on-disc tribometer at 10 N and 0.20 m/s from RT to 800°C sliding against Si3N4 ceramic ball.The boron element greatly improves the wear resistance of specimens as compared with that of unreinforced specimen.The friction coefficients of specimens decrease with increasing of testing temperature.The wear rates of Fe-Cr-B alloys decrease firstly and then raise with the increase of boron content.The specific wear rates of specimens with boron are 1/10 of the unreinforced specimen.Fe-21wt%Cr-7wt%B keeps the best tribological properties at high temperature.

Practical Performance of High Bulk Modulus Oil

Although hydraulic drives have an advantage of high power density, volumetric shrinkage of hydraulic fluids due to pressure causes various disadvantages such as delay of hydraulic response and compression energy loss. Hydraulic fluids of new concept, high bulk modulus oils, have been developed as a new approach to improve the performance of a hydraulic servo system and verified. In this paper, practical performances of high bulk modulus oil, such as oil temperature rise during pump test, air bubbles generation by ultrasonic wave vibration, oxidation stability and anti-wear property, were studied. And the new oil was confirmed to have excellent practical performances besides advantages in pressure response and volumetric efficiency of pumps. Various new applications of the new oil are promising.