凿井绞车的设计【含CAD图纸、说明书】
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Outside text dataThe hot processing of metals is to put the metals work piece in certainly lie quality to heat the feat temperature, and after this keep certain time in the temperature, again with a kind of craft method that the different speed cool off. The hot processing of metals is one of the important craft within the machine manufacturings, processing the craft to compare with the other, the hot processing does not change the shape and whole chemistry compositions of the work piece generally, but pass to change the work piece inner part of show minute details the organization, or change the chemistry composition of a surface, giving or improving the usage function of the work piece.Its characteristics is an inside quantity that improves the work piece, but this is not the naked eye generally to can see of. For make the metals work piece have need of mechanics function, the physics function and the chemistry function, in addition to reasonable choosing to use the material and variously taking shape the craft, the hot processing craft is usually essential to have of.The steel is an applied most wide material in the machine industry, the steel shows minute details the organization complications, can pass hot the processing gives the control, so the hot processing of the steel is a metals hot processing of main contents.Moreover, aluminum, copper, magnesium .etc. and its metal alloys can also change the different from the chemistry function, to acquire usage function of its mechanics, physics through a hot processing. In 1863, the British gold learned the different from the geologist displayed the steel under the microscope of six kinds ofly gold of house mutually to organize mutually, proving the steel while heating and cooling off, the inner part will take place the organization change, hour of heat in steel of mutually at nasty and cold change into a kind of harder mutually.Frenchman the Aositing receives the together plain and different theories of the iron of the virtuous establishment, and British the carbon of iron that the Aositing draw up at the earliest stage mutually diagram, lay the theories foundation for the modern hot processing craft first step.At the same time, the people still studied in the metals heating process of the hot processing to the protection method of the metals, to avoid to heat the process in the metals of oxidize and take off carbon etc. 1850-1880 years, carry on the protection heating to once have a series of patent for applied various air( such as hydrogen, coal gas, carbon monoxide.etc.).The British gram of 1889-1890 years acquires various metalses the patent of the shining hot processing. Since 20 centuries, the new technical transplantation of the development and others of the metals physics is applied, making the hot processing craft of metals get the larger development.A progress that shows the is 1901-1925 years, the application turns the tube stove to carry on the air carbon in industry produce;The 30s appears the dewdrop potential difference to account, making the carbon of the atmosphere inside the stove attained certainly can control, hereafter again study to use the red and outside instrument, oxygen of carbon dioxide to stretch forward etc. the further control stove inside the atmosphere carbon power of method;60s, the hot processing technique made use of etc. the function of the ion field, developped the ion nitrogen, carbon craft of ;Technical application of laser, electron beam, and then make the metals acquire the hot processing method of the new surface heat processing and chemistries. The hot processing craft includes the heating, heat preservation and cools off three processes generally, sometimes only heating and cooling off two processes.These processes connect up properly with each other, cant interrupted. The heating is one of the important steps of the hot processing.The metals heating method of the hot processing is a lot of, at the earliest stage is to adopted the charcoal and coals to be the hot source, then applied the liquid and gaseous fuels.The application of the electricity makes heat to be easy to the control, and have no pollution of the environment.Make use of these hot sources can heat directly, can also pass the salt or metalses of the meltdown, to go to float a son to carry on the indirect heating. When the metals heat, the work piece expose up in the air, usually take place to oxidize, take off the carbon( namely the steel spare parts surface carbon content lower), this to the hot processing behind spare parts of surface function have the very disadvantageous influence.As a result metals usually should in can control atmosphere or protect atmosphere, the meltdown salt moderates the vacuum in the heating, also can use the coating or packing the method carries on the protection heating. Heat the temperature is one of the important craft parameters of the hot processing craft, choosing and controling the heating temperature, is a key problem that guarantees the hot processing quantity.Heat the temperature with the metals material and hot processings that is handles of purpose be different, but generally is all to heat to change the temperature mutually above, to acquire the organization of demand.Change to need certain time moreover, so when a surface of the metals work attains the heating temperature of request, return must keep certain time in this temperature, make is consistent inside the outside temperature, making show minute details the organization the change completely, this time is called heat preservation time.Adoption high ability density heat and hot processing of surface, very heat the speed quickly, general have no heat preservation time or the heat preservation time very short, but chemistry hot processing of heat preservation time is usually longer. The cooling also is indispensable in the hot processing craft process of step, cool off method dissimilarity because of craft dissimilarity, mainly is a control cooling speed.Back the cooling speed of the fire generally the slowest, positive fire of cooling speed compare quickly, fire of cooling speed sooner.But return to have the different request because the steel grows the dissimilarity, for example the empty hard steel can use the similar cooling speed of positive fire to carry on the hard. The hot big body of craft of processing of metals can is divided into whole hot processing, surface hot processing, part hot processing and chemistry hot processing etc.Lie the quality and heat the temperature and cool off the dissimilarity of method according to the heating, each a major type can classified into some hot processing crafts of dissimilarity again.The same kind of metals adopts the different hot processing craft, can acquire the different organization, thus having the different function.The steel is an industry up the applied most wide metals, and the steel show minute details organization also the most complicated, therefore steel hot processing the craft category numerous. Whole and hot processing is to a whole heating of work, then cool off with the appropriate speed, to change the metals heat processing craft of its whole mechanics function.The whole hot processing of steel mostly backs the fire, positive fire, fire of and returns to four kinds of basic crafts of fire. Back the fire is to heat the work piece to the appropriate temperature, according to different from work piece size adoption heat preservation time of material, then carry on slow-moving cool off, the purpose is to make the metals internal organization attain or near to the equilibrium, acquiring the good craft function and using the function, or make the organization preparation for the further fire of .The positive fire is to heat the work piece to the feat temperature behind up in the air cooling, positive fire of result together back the fire likeness, the organization that just get is thinner, in common use in improvement the material slices to pare the function, also sometimes useding for being the end hot processing to the not high spare parts of some requests. Fire of is heat the work piece heat preservation after, in water, oil or others have no machine salt, organic aqueous solution wait coldly lie quality fast cooling.The steel piece becomes after the fire of hard, but change the frailty at the same time.For lowering the brittleness of the steel piece, carry on fire of behind of the steel piece at high in indoor temperature but low in 710 some appropriate temperatures of the s long-playing heat preservation, then carry on the cooling, this kind of craft is called to return to fire.It is four firess within whole and hot processings to back the fire, positive fire, fire of and return to fire, the fire of that is among them with return to the fire relation close, usually match with the usage, lack a cant. Four fires along with heat the temperature and cool off the dissimilarity of way, and then turn into a different and hot processing craft.For acquiring the certain strength and tenacities, the craft that the fire of and heat returns to the fire knot to put together, be called to adjust the quality.Some metal alloys fire formation supersaturation after is solid dissolve the body place it in indoor temperature or slightly high and appropriate temperature descend keep to compare the long time, to raise degree of hardness, strength or electricity magnetism etc.s of the metal alloy.The hot processing craft that is thus is called the time limited efficacy processing.Process the form to the pressure to change is valid with hot processing but closely the knot puts together to carry on, making the work piece method that acquires the good strength, tenacity to match with be called the form to become the hot processing;Carry on hot in take press atmosphere or vacuums the processing is called the vacuum hot processing, it not only can make the work piece does not oxidize, dont take off the carbon, a surface of work is clean after keep processing, raise the function of the work piece, but also can open into the of to carry on the hot processing of chemistry. The hot processing of surface heats a surface layer of work only, to change the metals heat processing craft of its surface layer mechanics function.For heating a surface layer of work but donting make the excessive calories stream into an inner part of work only, the hot source beard of the usage has the high energy density, giving on the work piece of the unit area bigger thermal energy, make a surface layer of work or part ability short time or attain the heat in a moment.Surface hot processing of main method, have the laser hot processing, the flames fire and respond the hot processing of heating, the in common use and hot source contain the oxygen B or oxygen propane etc. flameses, respond the electric current, laser and electron beam etc. The hot processing of chemistry is the metals heat processing craft that passes to change a surface layer chemistry composition, organization of work and functions.The chemistry hot processing and the surface heats handle the different place is the chemistry composition that the latter changed a surface layer of work.Hot processing of chemistry is put the work piece in contain carbon, nitrogen or other metal alloy chemical elements lie quality( air, liquid, solid) heating, the heat preservation compare with long hours, thus make the chemical elements, such as a surface layer infiltration carbon, nitrogen, of work and chrome.etc.After seeping into the chemical element, sometimes still need to carry on other hot processing crafts,such as fire of 淬 , and return to fire.Chemistry the main method of the hot processing contain carbon, nitrogen, metals, the compound .etc. The hot processing is one of the machine spare parts and important work preface within the work molding tool manufacturing processes.Big body to say, it can guarantee and raise various function of the work piece, if bear to whet, bear corrosion etc.Can also improve the organization of the semi-finished product and should the dint appearance, for the convenience of in carry on various cold, the heat process. For example an iron casting pass by to back with long hours the fire processing and can acquire can iron casting, exaltation;The wheel gear adoption the hot processing of the exactitude craft, the service life can compare not through hot processing of wheel gear become doubly or several decuples ground exaltation;Moreover, the carbon steel of the low price passes to seep into the metal alloy steel function that some metal alloy chemical elements have some prices, can replace the some and heat-proof steel, stainless steel;The work molding tool then almost all demands can use through hot processing square.外文资料翻译金属热处理是将金属工件放在一定的介质中加热到适宜的温度,并在此温度中保持一定时间后,又以不同速度冷却的一种工艺方法。 金属热处理是机械制造中的重要工艺之一,与其它加工工艺相比,热处理一般不改变工件的形状和整体的化学成分,而是通过改变工件内部的显微组织,或改变工件表面的化学成分,赋予或改善工件的使用性能。其特点是改善工件的内在质量,而这一般不是肉眼所能看到的。 为使金属工件具有所需要的力学性能、物理性能和化学性能,除合理选用材料和各种成形工艺外,热处理工艺往往是必不可少的。钢铁是机械工业中应用最广的材料,钢铁显微组织复杂,可以通过热处理予以控制,所以钢铁的热处理是金属热处理的主要内容。另外,铝、铜、镁、钛等及其合金也都可以通过热处理改变其力学、物理和化学性能,以获得不同的使用性能。 1863年,英国金相学家和地质学家展示了钢铁在显微镜下的六种不同的金相组织,证明了钢在加热和冷却时,内部会发生组织改变,钢中高温时的相在急冷时转变为一种较硬的相。法国人奥斯蒙德确立的铁的同素异构理论,以及英国人奥斯汀最早制定的铁碳相图,为现代热处理工艺初步奠定了理论基础。与此同时,人们还研究了在金属热处理的加热过程中对金属的保护方法,以避免加热过程中金属的氧化和脱碳等。 18501880年,对于应用各种气体(如氢气、煤气、一氧化碳等)进行保护加热曾有一系列专利。18891890年英国人莱克获得多种金属光亮热处理的专利。二十世纪以来,金属物理的发展和其它新技术的移植应用,使金属热处理工艺得到更大发展。一个显著的进展是19011925年,在工业生产中应用转筒炉进行气体渗碳 ;30年代出现露点电位差计,使炉内气氛的碳势达到可控,以后又研究出用二氧化碳红外仪、氧探头等进一步控制炉内气氛碳势的方法;60年代,热处理技术运用了等离子场的作用,发展了离子渗氮、渗碳工艺;激光、电子束技术的应用,又使金属获得了新的表面热处理和化学热处理方法。 热处理工艺一般包括加热、保温、冷却三个过程,有时只有加热和冷却两个过程。这些过程互相衔接,不可间断。 加热是热处理的重要步骤之一。金属热处理的加热方法很多,最早是采用木炭和煤作为热源,进而应用液体和气体燃料。电的应用使加热易于控制,且无环境污染。利用这些热源可以直接加热,也可以通过熔融的盐或金属,以至浮动粒子进行间接加热。 金属加热时,工件暴露在空气中,常常发生氧化、脱碳(即钢铁零件表面碳含量降低),这对于热处理后零件的表面性能有很不利的影响。因而金属通常应在可控气氛或保护气氛中、熔融盐中和真空中加热,也可用涂料或包装方法进行保护加热。 加热温度是热处理工艺的重要工艺参数之一,选择和控制加热温度 ,是保证热处理质量的主要问题。加热温度随被处理的金属材料和热处理的目的不同而异,但一般都是加热到相变温度以上,以获得需要的组织。另外转变需要一定的时间,因此当金属工件表面达到要求的加热温度时,还须在此温度保持一定时间,使内外温度一致,使显微组织转变完全,这段时间称为保温时间。采用高能密度加热和表面热处理时,加热速度极快,一般就没有保温时间或保温时间很短,而化学热处理的保温时间往往较长。 冷却也是热处理工艺过程中不可缺少的步骤,冷却方法因工艺不同而不同,主要是控制冷却速度。一般退火的冷却速度最慢,正火的冷却速度较快,淬火的冷却速度更快。但还因钢种不同而有不同的要求,例如空硬钢就可以用正火一样的冷却速度进行淬硬。 金属热处理工艺大体可分为整体热处理、表面热处理、局部热处理和化学热处理等。根据加热介质、加热温度和冷却方法的不同,每一大类又可区分为若干不同的热处理工艺。同一种金属采用不同的热处理工艺,可获得不同的组织,从而具有不同的性能。钢铁是工业上应用最广的金属,而且钢铁显微组织也最为复杂,因此钢铁热处理工艺种类繁多。 整体热处理是对工件整体加热,然后以适当的速度冷却,以改变其整体力学性能的金属热处理工艺。钢铁整体热处理大致有退火、正火、淬火和回火四种基本工艺。 退火是将工件加热到适当温度,根据材料和工件尺寸采用不同的保温时间,然后进行缓慢冷却,目的是使金属内部组织达到或接近平衡状态,获得良好的工艺性能和使用性能,或者为进一步淬火作组织准备。正火是将工件加热到适宜的温度后在空气中冷却,正火的效果同退火相似,只是得到的组织更细,常用于改善材料的切削性能,也有时用于对一些要求不高的零件作为最终热处理。 淬火是将工件加热保温后,在水、油或其它无机盐、有机水溶液等淬冷介质中快速冷却。淬火后钢件变硬,但同时变脆。为了降低钢件的脆性,将淬火后的钢件在高于室温而低于710的某一适当温度进行长时间的保温,再进行冷却,这种工艺称为回火。退火、正火、淬火、回火是整体热处理中的“四把火”,其中的淬火与回火关系密切,常常配合使用,缺一不可。 “四把火”随着加热温度和冷却方式的不同,又演变出不同的热处理工艺 。为了获得一定的强度和韧性,把淬火和高温回火结合起来的工艺,称为调质。某些合金淬火形成过饱和固溶体后,将其置于室温或稍高的适当温度下保持较长时间,以提高合金的硬度、强度或电性磁性等。这样的热处理工艺称为时效处理。把压力加工形变与热处理有效而紧密地结合起来进行,使工件获得很好的强度、韧性配合的方法称为形变热处理;在负压气氛或真空中进行的热处理称为真空热处理,它不仅能使工件不氧化,不脱碳,保持处理后工件表面光洁,提高工件的性能,还可以通入渗剂进行化学热处理。 表面热处理是只加热工件表层,以改变其表层力学性能的金属热处理工艺。为了只加热工件表层而不使过多的热量传入工件内部,使用的热源须具有高的能量密度,即在单位面积的工件上给予较大的热能,使工件表层或局部能短时或瞬时达到高温。表面热处理的主要方法,有激光热处理、火焰淬火和感应加热热处理,常用的热源有氧乙炔或氧丙烷等火焰、感应电流、激光和电子束等。 化学热处理是通过改变工件表层化学成分、组织和性能的金属热处理工艺。化学热处理与表面热处理不同之处是后者改变了工件表层的化学成分。化学热处理是将工件放在含碳、氮或其它合金元素的介质(气体、液体、固体)中加热,保温较长时间,从而使工件表层渗入碳、氮、硼和铬等元素。渗入元素后,有时还要进行其它热处理工艺如淬火及回火。化学热处理的主要方法有渗碳、渗氮、渗金属、复合渗等。 热处理是机械零件和工模具制造过程中的重要工序之一。大体来说,它可以保证和提高工件的各种性能 ,如耐磨、耐腐蚀等。还可以改善毛坯的组织和应力状态,以利于进行各种冷、热加工。 例如白口铸铁经过长时间退火处理可以获得可锻铸铁,提高塑性 ;齿轮采用正确的热处理工艺,使用寿命可以比不经热处理的齿轮成倍或几十倍地提高;另外,价廉的碳钢通过渗入某些合金元素就具有某些价昂的合金钢性能,可以代替某些耐热钢、不锈钢;工模具则几乎全部需要经过热处理方可使用。 - 10 -
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