Abstract：Starting from wearing hilure analysis，the author introduces the structure and shape，mutual matching relation，manutacturing engineering of wear— resisting ma terisls，quality control and applica—tion characteristics of dama geable parts in crushing and grinding system and enumerates chemical cornportents and mechanical properties of typical wear- resisting materials at home and abroad．The developmerit of wear— resisting materials is also given in this article．
1、Introduction
Metallurgical mining, building materials, thermal power generation, chemical, coal, and other industrial sectors, the need for various broken Fenmo equipment. These pieces of equipment vulnerable groups affected by the ground, trying protected, material wear and tear, the annual consumption of the metal. For feeding to the cement industry, 1994 production of 405 million tons of cement nationwide. Ball mill Chenban category, Breakers category depletion of metal about 300~ 350g/t cement; Most medium (ball, above) 500g/t cement, such as young as 1994 on the cement industry consumed 120000t Chenban type metal, grinding bodies 2o more. According to relevant statistics, black, colored metal mines exertion more, the National exertion Breakers, ball mill lining protected metal about 50000t, about 130 km medium metal with a total value of 80 billion. Material consumption is reflected in energy consumption, thus saving energy and reducing consumption of materials metals an important aspect of a very clear economic and social benefits. At the same time as a result of the replacement of forced relocation of parking time in the cement industry about the total parking time 55~50, representing an increase of wear and tear of equipment maintenance workload 60 ~65, with broken equipment crafts Fenmo rapid development of technology, with increasingly large-scale equipment development and use of new wear-resisting material growing importance.
2、Broken Fenmo equipment wear and tear
Fenmo broken equipment wear and tear can be divided into internal factors and external factors. Internal factors include the quality of materials metallurgy, chemical composition, metallography and mechanical properties of materials I external factors including the hardness and toughness, size and edges and corners Ruiduo etc. Size pieces depending on whether the material durable resistance to wear and tear ability to resist fatigue wear capacity-lung machine and ploughs cut capacity. The size of several major pieces of equipment broken Fenmo wear a summary analysis. Broken anti-aircraft teeth every.
2.1 Jaw breakers teeth plate
Jaw-Breakers teeth plates worn to holes cut-worn. Jiangsu Changshu quarries to use PZ250~500-jaw style Breakers teeth protected, for example, the teeth are protected by the materials handling water standards high manganese steel fasteners. In scanning call youthful observation teeth wrenched himself face can be seen, teeth protected by squeezing out as much of the surface material, followed by a pressure abrasive tongue pushing himself face, can be seen in the upper surface of many abrasive edges because the marks are caused by short-range sliding, and may see a slight cracks teeth board surface, see figure 1.
After analysis, teeth wrenched worn mainly abrasive relative teeth board short sliding, cutting metal grinding scrap and abrasive repeatedly squeeze caused teeth protected materials on deformation, resulting in the metal materials off fatigue, loss of skills to teach the course are : (1) materials repeatedly squeeze hole cut teeth arranged in the teeth protected area surface, or in metal squeeze the highlights roots form micro cracks, linked to the continued expansion of micro-cracks, causing the surface of metal materials separated, forming himself crumbs. (2) Section objects repeatedly squeeze, causing teeth wrenched metal materials were partially closed or residents to reveal the fragmentation or residents to reveal some of the materials and the impact to squeeze off a difficult scrap (3) material relative teeth short-range sliding panels, a difficult scrap carbide teeth boards.
Therefore teeth from wear-resisting material control panels worn mainly hardness and resilience. Hard materials, materials squeeze shallow depth, material deformation small, short-range sliding cutting materials volume of the material is also good resilience of small materials, a strong ability to resist fracture, the impact may be removed squeeze process brittleness fracture, raising anti-fatigue deformation shell capacity.
Jaw-Breakers different size specifications, feed granularity, Ruiduo different panels of the squeezing out teeth, different impacts of large and medium-sized squeeze pressure, apart from the material to resist pressure and to resist squeeze sliding brackets, should also consider the impact of the impact and bending stress the large teeth board composition should use high resilience, good overall performance materials.
From the above analysis shows wear ineffective for teeth board material should choose hardness high resistance materials to squeeze, lung machine failures, the choice of materials sufficient to resist cutting Bo resilience cut impact fatigue failure. At the same time to improve the structure of boards from the teeth, and tooth plates to reduce the relative sliding materials, useful not only for increasing productivity but also to improve the material life useful.
2.2 Hammer breakers head
Different specifications hammer-Breakers, head shape and size vary, it is generally thought that the head 90~125kg for large, 25kg Following is a small, and the rest for medium. Dazhong plant general use 25~50kg head.
The head and sizes and the use of the state of different conditions, the wear and tear of its failure vary. The head wear, with the impact of the cut-cut, accompanied by heavy lung machine wear. Externalities for impact craters and its worn cutting plow Gap. The head wear and tear of the main ways to attack, so do head people accustomed to the choice of high manganese steel materials.
(1) The following head one 2kg
Because of its extremely small jumping, Jiagongyinghua can not give full play to the role of high manganese steel, resistance to abrasion from ideal, such as broken feldspar, Liezhimei and blast furnace slag and other materials, head in a few days or even a few classes, some failures. It was reported by 5.8kg to 11.5kg head and cement used to wear head after mutilated body lapse analysis revealed two head Jiagongyinghua results are poor surface hardening curve shown in figure 2.
The wear process is small head materials on the one hand small energy shocks head, a metal surface deformation and plasticity Emblem cracks. Just change many times in the expansion of cracks, metal debris particles formed by squeezing out, leading to shocks wear; On the other hand materials tips surface materials in a certain law is the power to influence and role of the surface of metal materials have lung machine, washed, worn metal surfaces, but because of the impact of power, high manganese steel to be Jiagongyinghua. Therefore, it is necessary to choose a certain resilience to the high hardness of the material can lead to a substantial increase useful life.
(2) 50kg class head
Because of its great impact, high manganese steel materials using high resilience, its performance has been Jiagongyinghua must play head to wear, impact and cut-cut, micro machining with heavy wear and tear, wear micro externalities performance for impact craters and cutting plow Gap. However, if the material conditions of the state are different, the same is the use of high manganese steel head also a big difference. Shaanxi River is the same as cement plant production 12P 50kg class high manganese steel head in eternal plant only applications 2~3 months failures; Cement plant in Yaoxian available 8~11 months.
Dianjingguancha eternal in the plant head worn surface mainly cutting plow Gap, impact craters exist on the expiry of their worn mainly by cutting mechanisms to wear and tear, accompanied by impact. Analysis because the plant limestone materials, including large quantities of mud, small granularity to reduce the impact load, high manganese steel processing hardness less, and often with high hardness of the material silica slate of high manganese steel austenitic like Zeikowa acuminata is a hard metal knife, leaving many cut trench, so wear faster.
Yaoxian plant is head wear face major impact craters, and a small cut below, the impact that it is worn mainly by cutting wear and tear, it is because the limestone pieces for the Great Yaoxian plant, and evenly, the impact great. Limestone and the impact of a head wear face many impact craters, craters are visible around here. The high manganese steel have good plasticity, is in abrasive impact of the formation of impact craters and easier plasticity deformation; On the other hand, because of the larger impact of high manganese steel to be Jiagongyinghua, increased deformation resistance, and thus demonstrated higher wear-resistant ability.
As can be seen from the above analysis : in a cut-based cases, the hardness of the poetry of resistance to abrasion lead role to solve this problem, we Hubei cement plant with a super-high manganese steel in the development of high-resilience premise ten feet of improving its yield strength (up to 450N/ram. ), to increase the initial hardness HB260~300. at the same time improving its Jiagongyinghua rate, the longevity Life significantly improved.
(3) Large Breakers 90kg and 125kg head
To do its work to 90kg head parameters as shown in table 1.
Table 1 shows the aggregate size of the Breakers into large, broken than large, high rotational speed, the head impact of the large impact on the wear and tear on machinery. Material should lead to resilience to combine hardness, intensity, integrated performance. Cement kilns, March t983 use from Germany O8 Ⅸ company introduced MB70/90-hammer-style Breakers, 90kg head is double the original metal casting, with his head high chromium cast iron, hammer handles in low alloy steel, the use of head cut off, combining Department fracture more affected normal production, the threat of whole sets of safety July 1986 imports O&K companies Shan metal 90kg head, the average use of 10 months broken 1800000 t limestone. Tangshan cement plant in the country head autopsy analysis book basis and high manganese steel head, 1991, through ministerial identification. ~18 containing manganese steel up to 17, mainly to enable head Houda, the center for the entire Department generally maintain its excellent resilience, the use of reliable, increase Cr Mo and other elements to improve overall yield strength and initial hardness, the performance needs of production. Wear and tear on the above description to the impact of the vulnerability to choose materials and supplemented by other high-resilience integrated performance. The wear and tear of the ball mill Chenban
2.3 Ball (control) mills and the Chenban bear Moqiu materials shocks, cut, squeeze and lung machine multifaceted role of worn surface features is a crater, crackle and ploughs Gap. And the degree of wear materials characteristics, size, nature Ruiduo living skills, but also with the rod diameter size specifications, Chenban which parts. 2.2m x 6.5m to cement mills to do, a warehouse, two positions high manganese steel surface of a mirror Chenban worn photographs shown in figure 3 and figure 4.
Photo from a warehouse in the foreseeable Chenban many ploughs Gap and spalling pit, because a warehouse for 70~80mm average ball Drive, the largest ball to 90~100mm, average granularity 25ram materials, the largest up to 40mm, and sharp edges and corners; Two positions for the ball Drive 30~50mm ~35mm x 30mm or below steel. Materials from one warehouse was broken into two panels after booths warehouse stores, granularity has become 5ram around edges and corners Ruiduo has greatly reduced, so two positions Chenban mainly lung machine, squeezing out accumulation and salt Board 4 worn.
Feed-Motouchenban Because of the larger equipment and materials granularity sports large, sharp edges and corners of the side impact and sliding hill, than expected - comb plates wear out much more serious. It positions panels back one or two positions balls side shocks, but also to materials through hoof off by washed lung machine, and therefore wear is also more serious if it requires board positions both wear resistance capacity is not broken, we should have a higher yield strength and hardness, resistance to bending, resistance materials washed maintain comb linking width, crafts meet requirements, it should choose the good resilience high hardness of the material. Even with a hammer Chenban not wear different parts Korea, for example - Chenban, Central Chenban affected by the impact of materials and Moqiu serious, especially to greet expected face more and more light is close to the tail device. Receiver Chenban whether ladder, prominent corner, layering, etc. Chenban welcome by cutting spherical expected, the impact of serious Chenban production processes in different parts of China should consider the resistance to abrasion resistance to wear and tear, or from the structural design of improvements, such as Motou - Chenban welcome Liu noodles plus corner; A warehouse village board will double ladder; It positions boards worn parts add thickness, and so on. In Chenban wear is a systems engineering, needles To different conditions and the status of the corresponding wear-resisting material.
2.4 Grinding balls wear out
Moqiu ball in the Moldovan plane is the largest metal work exertion. We are different materials, the use of the situation in different conditions Moqiu analysis shows the wear and tear Moqiu lapse following several mechanisms:
(1) cut and cut wear and tear. Moqiu rise in the upper stage, with relatively sliding materials, which were hard and sharp materials on the surface of a deeper trench cut by Jinger materials is a less blunt the trench, the size of different materials, different soft and hard acute, resulting in the ball below the surface mine shallow, narrow differences crosscutting. Moqiu slow down to a certain point, the impact of materials, a partial cut a hole worn.
(2) deformation wear. Moqiu and materials relative sliding or shock, direct cutting, cut, there are ploughs Gap deformation occurred, and the metal was pushed to the naked eye below the outer side, in the role of metal deformation materials repeatedly by a contingency fatigue cracks, cracks expand, connecting, forming plow scrap sheet, the surface area.
(3) brittleness spalling. Moqiu affected by the impact of the process materials brittleness of (such as carbon) shell, broken down by himself from the surface Zhuo filings.
(4) fatigue wear. Moqiu in mills within the cycle of rise, throw, repeatedly sliding, rolling and impact of changes in shocks contact pressure stress, is the role of a stress fatigue in Asia surface fatigue cracks formed parallel to each other, forming an extension of fatigue spalling and surface layer. Fatigue cracks in Asia next life consisting of a mixture of nuclear material and brittleness can grow in the surface layer and the dynamics softened layers asked for nuclear. When the casting surface in much of the wrong and mixed nuclear expansion will lead to macro fatigue spalling, or a piece of debris caused by ball joints stolen Yuan. Near the surface and lead to micro-nuclear fatigue spalling, a finding lamina and spalling pit.
