长寿命贝氏体钢耐磨衬板研究

在港口、矿山散货作业中,衬板用于各种漏斗的内衬,直接承受煤炭、矿石的冲击磨损.就如何提高衬板的抗冲击性、抗磨损性,以减少衬板更换次数,不少行业专家研究了许多耐磨材料,本文介绍一种新型贝氏体耐磨铸钢材料,从理论分析、实验、到现场漏斗测试,说明贝氏体铸钢兼有硬度高、韧性好、成本低等优点,是今后散货作业设备上值得推广使用的新型衬板材料.     

胶带运输机料嘴改进

本文叙述了胶带运输机料嘴衬板磨损和料嘴堵矿的原因，分析了胶带运输机料嘴料板磨损，脱落等生产带来的种种弊病，提出了解办法，斜形料嘴改进为直方形料嘴。     

可用于煤料运输的UHMW-PE衬板

针对煤料运输系统中最常见的溜槽堵塞故障,分析其产生的原因及对煤料运输系统的影响,提出在系统内铺设一种超高分子量聚乙烯的新型材料作衬板,以改善该系统的运转状况。建议在相关行业中推广应用。     

一体式缓冲机架在400烧结机配料系统的应用

型钢炼铁厂400烧结配料系统所配物料粘度较高,且矿粉中含杂草、杂物较多,导致振动筛筛下溜槽及漏斗粘料严重。2015年初对筛分间两台振动筛筛下漏斗进行扩容改造,改造完成并运行两周后,振筛岗位人员发现PL1、PL2皮带机尾漏斗落料点处托辊、托辊支架受物料冲击较严重,造成缓冲托辊、缓冲垫发生脱落,必须定期进行更换。为了降低托辊、托辊支架消耗,经过现场分析,设计并加工生产了一体式缓冲机架,该机架能够承受物料较大冲击较,减少粘料现象,消除了雨季堵漏斗频繁等问题,确保3#烧结机生产稳定高效。     

耐磨陶瓷在高炉炉顶装料设备上的应用与调研

耐磨陶瓷近年被广泛应用于钢铁、冶炼、机械、煤炭和矿山等企业的输煤、输料、制粉及除尘系统等磨损大的机械设备上。中大型炼铁高炉上的无料钟炉顶装料设备,也是磨损大的机械设备,也使用了大量的耐磨衬板,但使用寿命和性价比始终不能同时满足炉顶装料设备公司和用户的要求,如果耐磨陶瓷能在无料钟炉顶装料设备上广泛的应用和推广,前景应该是非常可观的。     

高炉布料溜槽抗磨损结构设计及优化

针对高炉布料溜槽的磨损失效,对溜槽进行了抗磨损结构设计和优化。在分析炉料运动和溜槽磨损的基础上,确定采用料磨料式和光面式衬板相结合的溜槽结构,并采用离散单元法分析了不同厚度料垫的炉料缓冲效果,根据高炉装料制度对溜槽耐磨衬板的结构参数进行了优化。结果表明：溜槽磨损属于磨料磨损,在炉料冲击区域设置不小于60mm厚的料垫,能够有效分散炉料对溜槽的冲击,减少磨料磨损,优化后的料磨料式衬板在溜槽底部多储存了32.13%的炉料,溜槽总过料量增加了15.5%。     

振动放矿机漏斗存在的问题及改进

通过对振动放矿系统长期以来存在的问题进行分析,参考国内外矿山使用振动放矿机的经验,结合西破振动放矿机漏斗的特点,对传统的振动放矿机漏斗衬板安装方式进行改进,采用在放矿机漏斗正方体与四棱椎体连接处安装1760 m m×1760 m m×50 m m的"回字型"衬板的方法,延长振动放矿机漏斗内易磨损衬板的使用寿命,减少振动放矿机漏斗检修频次,节约了成本,提高了经济效益。     

翻车机隔栅自动同步清料、报警装置

翻车机是铁路运输业对装有散料的车皮进行快速倾卸的大型机械 ,它直接将整车皮的散状物料一次性地倾卸到漏斗仓中。为了缓解翻车机倾卸时对下层设备的冲击 ,隔阻车皮内散料中夹杂的异物“大块”被倾卸到漏斗仓内 ,从而引发输送料线的后序事故 ,一般都在漏斗仓上部设置有隔栅层。隔栅层通常由条形铁板焊接而成 ,其竖立面间隔一般为 30 0mm× 30 0mm的“井”字空间 ,它安装在整个漏斗仓的顶部。隔栅层在发挥功能的同时 ,客观上也把车皮倾卸的部分物料截留在“井”字形竖立面的交叉点上形成了积料。如果把“井”字空间扩大来减少隔栅的交叉点 ,…     

关于桥式抓斗卸船机漏斗耐磨衬板问题的分析

对桥式抓斗卸船机漏斗耐磨衬板的种类和形式做了简单介绍,分析了不同耐磨衬板材料的属性和耐磨机理,阐述了影响耐磨衬板寿命的因素。结合实际生产实践,提出了合理安装和维护耐磨衬板的措施。     

延长衬板寿命的方法

我公司2500m~3高炉上料系统采用双机带式运输机传送,在其转运站中,采用翻板4实现运料从一条输送带2向另一条输送带转运(图1)。翻板4上安装衬板5。烧结矿从上一层输送带经漏斗收集后,直接落在衬板5上,落差2m。对衬板5造成强烈冲击。衬板5磨损严重,试用多种耐磨材料,效果均不理想。用我厂专门试制的高铬铸铁衬板,kmT-BCr15Mo2DT(厂内牌号)也仅用20天左右即报废,这不到60天的设计寿命。经过试验,我选用高铬铸铁为材料,将原设计的平面型材板改为L形(见图2)。给衬板增加一个直角边,根据衬板的工作位置,取H=     

转载溜槽衬板磨损预测的DEM仿真方法

针对EDEM自动划分网格较稀疏问题,采用Hypermesh划分仿真模型网格,利用Herz-Mindlin接触理论的Archard磨损模型对转载溜槽磨损问题进行仿真,在网格单元上提取出漏斗和溜管衬板的接触能量和磨损量,分析了磨损量与接触能量的关系。假设转载溜槽衬板磨损深度为物料与溜槽衬板的使用时间为线性函数,根据现场衬板磨损量的测量值,将衬板的磨损系数关系的看作隐式的单变量方程,应用EDEM软件的仿真结果求解出磨损系数的标定值。分析了漏斗和溜管的磨损机理。该方法可用于转载溜槽的磨损预测。     

Effects of mechanical properties on the tribo-electrification mechanisms of iron rubbing with carbon steels

The mechanisms of tribo-electrification and the associated wear behavior of a pair of dissimilar metals in the form of a pin and a plate rubbing against each other under dry severe wear condition were investigated using a reciprocating friction tester. The materials were iron and carbon steels of 0.2%, 0.45% and 0.7% carbon. Results showed that when an iron pin rubbed against the steel plate specimens, increasing the carbon content caused the formation mechanism of the wear particle to vary from macro-asperity removal to yielding wear. The material adhesive transfer was mainly from the pin to the plate specimen due to yielding wear. Hence, the polarity of tribo-electrification for the pin specimen varied from random to positive. Consequently, a model that described this mechanism was proposed. Now, when the materials were reversed, i.e. the three types of carbon steels were used as the pin to rub against an iron plate, increasing the carbon percentage of the pin specimen resulted in the wear mechanism to vary from macro-asperity removal to grooving wear, the latter of which resulted in material transfer mainly from the plate specimen to the pin specimen. In contrast to the previous case, the polarity of tribo-electrification for the pin specimen varied from random to negative and a model that described this mechanism was proposed. Based on the above two models, a micro-model of tribo-electrification mechanism for self-mated materials was proposed. By using this micro-model, the mechanism of tribo-electrification in same material abrasion can be reasonably explained.     

贝氏体钢板与普碳板耐磨性对比试验

本文介绍了热轧低碳贝氏体高强钢板在QLK800．32型斗轮取料机上与普碳钢板进行耐磨性对比工业试验的情况。试验结果表明,贝氏体高强钢板的耐磨寿命可达到普碳板的3倍以上。     

平顶链安装方案的优化设计

提出平项链传输的常见问题，从运行轨道、侧面板及其固定轴的设计、输送带主动轮及从动轮固定板的设计以及链板轮的设计出发，介绍一款平顶链安装的优化设计方案，并阐述其使用效果。     

碳钢奥氏体不锈钢材料在水电工程中应用的局限性

通过对水电站典型应用材料(55钢、1Cr18Ni9Ti、0Cr13Ni5Mo)在冲蚀磨损过程中电化学腐蚀及抗冲蚀磨损性能研究,区分出纯磨损、纯腐蚀、磨损对腐蚀的促进分量及腐蚀对磨损的促进分量等在材料失效过程中各占的比例,考察了试验材料的抗冲蚀磨损特性及其磨损与腐蚀间的交互作用,分析了其失效机制。结果表明:不同的冲蚀速度下,0Cr13Ni5Mo不锈钢的冲蚀磨损失重率最小,55钢最大;纯磨损是材料失去的主要方式:55钢虽然纯磨损量较小,但腐蚀及其磨损与腐蚀的交互作用失去量大,1Cr18Ni9Ti不锈钢虽然纯腐蚀量小,但纯磨损量大,因而都有应用的局限性。     

Wear behaviour of a 3% Si steel during repeated frictional contact

Studies of the wear of 3% Si steel were made under conditions of repeated sliding over the same track with alternating contact and separation of the mating surfaces.Metal transfer occurred first from the plate specimen to the slider to form a large prow and then back transfer to the plate followed. Subsequently, a thick hardened surface layer, of maximum hardness greater than 800 HV, was formed by continual pile-up of transferred material. The formation of characteristic voids was observed within the layer. Quantitative X-ray microanalysis revealed that the increase in hardness is caused by cumulative severe plastic deformation and not by oxidation or changes in chemical composition. The variation in wear rate is discussed.     

热轧、低温回火态1250MPa级新型贝氏体耐磨钢板的组织和性能

研究了热轧、低温回火状态1250MPa级新型贝氏体耐磨钢板的组织和力学性能,测试了埋弧焊和CO2焊焊接接头的力学和机械加工性能。结果表明：轧态、低温回火耐磨板的组织由贝氏体铁素体和残余奥氏体组成,具有较高的力学性能、较高的回火抗力、良好的焊接性能和机械加工性能。     

地铁受电弓碳滑板冬季异常磨耗特点微观研究

以国内某地铁线路在冬季运行中出现异常磨耗的受电弓浸铜碳滑板为研究对象，借助多种微观测试手段，比较其表面形貌、微观组织、化学成分等与正常磨耗状态的碳滑板表面的差异，探究碳滑板出现异常磨耗的原因及机制。结果表明：与正常磨耗状态碳滑板相比，异常磨耗状态下碳滑板表面三维形貌崎岖且粗糙，其接触条件显著恶化，机械磨损、磨粒磨损、电弧烧蚀、材料转移等形式的磨损量均有增加；在进入秋冬季节后，碳滑板表面润滑条件发生改变、磨粒数量增加、直径增大、接触副温度上升，从而加剧了磨粒磨损和电弧烧蚀，造成碳滑板出现异常磨耗现象。对地铁运营过程进行跟踪监测后发现，碳滑板异常磨耗的出现与隧道内环境湿度的下降存在一定关联。     

The influence of strain hardening on steel erosion wear studied by analytical modelling of impeller testing

ABSTRACT

Abrasive wear of steel is a common problem in the mining industry. It was tackled by many researches using analytical and numerical approaches. Despite the advantages of the analytical models to provide quick and elegant solutions, they were derived using several assumptions limiting their applicability, such as e.g. rigid-plastic flow. However, the consideration of strain hardening during impact is crucial to depict a real behaviour of tool material, which changes its mechanical properties during collision. In this research, a new analytical model is invented describing the impact of steel plate with a solid rock, while the material of the steel plate is hardening during penetration and scratching. The model provides a frame of analytical equations based on the second Newton law and equations of motion in vertical and horizontal directions. The motion in vertical direction is considered as an indentation problem and the motion in the horizontal direction as a scratch problem. This model incorporates the most general Holloman representation of strain-hardening law to capture the relationship between microstructural characteristics of steels and wear resistance. It was shown that the indentation depth, the pile-up height, length of the scratch and erosion ratio directly dependant on the strain-hardening parameters in Holloman equation. The model predicts the maximum indentation depth and scratch length as a function of strength coefficient and strain hardening exponent, but also of impact angle, mass of the rock, position of impact at the surface of steel plate and coefficient of friction during metal movement. The model was tested qualitatively by comparison with impeller-tumbler experiments using different steel plates. The solution obtained from this model could be used for quick and easy evaluation of the steel for mining tools in an industrial environment.