機(jī)械專業(yè)英語(yǔ)文章中英文對(duì)照推薦5篇(編輯修改稿)

　

【文章內(nèi)容簡(jiǎn)介】 broader study of is the physics, chemistry, and engineering related to metals from ore extraction to the final 。冶金學(xué)是物理學(xué)、化學(xué)和涉及金屬?gòu)牡V石提煉到最后產(chǎn)物的工程學(xué)。Heat treatment is the operation of heating and cooling a metal in its solid state to change its physical to the procedure used, steel can be hardened to resist cutting action and abrasion, or it can be softened to permit 。按所采用的步驟，鋼可以通過硬化來抵抗切削和磨損，也可以通過軟化來允許機(jī)加工。With the proper heat treatment internal stresses may be removed, grain size reduced, toughness increased, or a hard surface produced on a ductile analysis of the steel must be known because small percentages of certain elements, notably carbon, greatly affect the physical 、細(xì)化晶粒、增加韌性或在柔軟材料上覆蓋堅(jiān)硬的表面。因?yàn)槟承┰?尤其是碳)的微小百分比極大地影響物理性能，所以必須知道對(duì)鋼的分析。Alloy steel owe their properties to the presence of one or more elements other than carbon, namely nickel, chromium, manganese, molybdenum, tungsten, silicon, vanadium, and of their improved physical properties they are used mercially in many ways not possible with carbon ，如鎳、鉻、錳、鉬、鎢、硅、釩和銅。由于合金鋼改善的物理性能，它們被大量使用在許多碳鋼不適用的地方。The following discussion applies principally to the heat treatment of ordinary mercial steels known as plain carbon this process the rate of cooling is the controlling factor, rapid cooling from above the critical range results in hard structure, whereas very slow cooling produces the opposite 。熱處理時(shí)冷卻速率是控制要素，從高于臨界溫度快速冷卻導(dǎo)致堅(jiān)硬的組織結(jié)構(gòu)，而緩慢冷卻則產(chǎn)生相反效果。A Simplified Ironcarbon Diagram 簡(jiǎn)化鐵碳狀態(tài)圖If we focus only on the materials normally known as steels, a simplified diagram is often ，經(jīng)常要用到簡(jiǎn)化鐵碳狀態(tài)圖。Those portions of the ironcarbon diagram near the delta region and those above 2% carbon content are of little importance to the engineer and are simplified diagram, such as the one in , focuses on the eutectoid region and is quite useful in understanding the properties and processing of %的那些部分對(duì)工程師而言不重要，因此將它們刪除。，這對(duì)理解鋼的性能和處理是十分有用的。The key transition described in this diagram is the deposition of singlephase austenite(γ)to the twophase ferrite plus carbide structure as temperature (γ)隨著溫度下降分解成兩相鐵素體加滲碳體組織結(jié)構(gòu)。Control of this reaction, which arises due to the drastically different carbon solubility of austenite and ferrite, enables a wide range of properties to be achieved through heat ，使得通過熱處理能獲得很大范圍的特性。To begin to understand these processes, consider a steel of the eutectoid position, % carbon, being slow cooled along line xx’ in the upper temperatures, only austenite is present, the % carbon being dissolved in solid solution with the the steel cools to 727℃(1341℉), several changes occur ，%的共析鋼，’線慢慢冷卻。在較高溫度時(shí)，只存在奧氏體，%的碳溶解在鐵里形成固溶體。當(dāng)鋼冷卻到727℃(1341℉)時(shí)，將同時(shí)發(fā)生若干變化。The iron wants to change from the FCC austenite structure to the BCC ferrite structure, but the ferrite can only contain % carbon in solid ，%的碳。The rejected carbon forms the carbonrich cementite intermetallic with position essence, the net reaction at the eutectoid is austenite %C→ferrite %C+cementite %。本質(zhì)上，%的碳→%的碳+%的碳。Since this chemical separation of the carbon ponent occurs entirely in the solid state, the resulting structure is a fine mechanical mixture of ferrite and prepared by polishing and etching in a weak solution of nitric acid and alcohol reveal the lamellar structure ofalternating plates that forms on slow ，產(chǎn)生的組織結(jié)構(gòu)是一種細(xì)致的鐵素體與滲碳體的機(jī)械混合物。通過打磨并在弱硝酸酒精溶液中蝕刻制備的樣本顯示出由緩慢冷卻形成的交互層狀的薄片結(jié)構(gòu)。This structure is posed of two distinct phases, but has its own set of characteristic properties and goes by the name pearlite, because of its resemblance to motherofpearl at low ，但它本身具有一系列特性，且因與低倍數(shù)放大時(shí)的珠母層有類同之處而被稱為珠光體。Steels having less than the eutectoid amount of carbon(less than %)are known as hypoeutectoid now the transformation of such a material represented by cooling along line yy’ in (%)的鋼稱為亞共析鋼?！?線冷卻的轉(zhuǎn)變情況。At high temperatures, the material is entirely austenite, but upon cooling enters a region where the stable phases are ferrite and and levellaw calculations show that lowcarbon ferrite nucleates and grows, leaving the remaining austenite richer in ，這種材料全部是奧氏體，但隨著冷卻就進(jìn)入到鐵素體和奧氏體穩(wěn)定狀態(tài)的區(qū)域。由截線及杠桿定律分析可知，低碳鐵素體成核并長(zhǎng)大，剩下含碳量高的奧氏體。At 727℃(1341℉), the austenite is of eutectoid position(% carbon)and further cooling transforms the remaining austenite to resulting structure is a mixture of primary or proeutectoid ferrite(ferrite that formed above the eutectoid reaction)and regions of ℃(1341℉)時(shí)，奧氏體為共析組成(%)，再冷卻剩余的奧氏體就轉(zhuǎn)化為珠光體。作為結(jié)果的組織結(jié)構(gòu)是初步的共析鐵素體(在共析反應(yīng)前的鐵素體)和部分珠光體的混合物。Hypereutectoid steels are steels that contain greater than the eutectoid amount of such steel cools, as shown in zz’ of the process is similar to the hypoeutectoid case, except that the primary or proeutectoid phase is now cementite instead of 。當(dāng)這種鋼冷卻時(shí)，’線所示，除了初步的共析狀態(tài)用滲碳體取代鐵素體外，其余類似亞共析鋼的情況。As the carbonrich phase forms, the remaining austenite decreases in carbon content, reaching the eutectoid position at 727℃(1341℉).As before, any remaining austenite transforms to pearlite upon slow cooling through this ，剩余奧氏體含碳量減少，在727℃(1341℉)時(shí)達(dá)到共析組織。就像以前說的一樣，當(dāng)緩慢冷卻到這溫度時(shí)所有剩余奧氏體轉(zhuǎn)化為珠光體。It should be remembered that the transitions that have been described by the phase diagrams are for equilibrium conditions, which can be approximated by slow slow heating, these transitions occur in the reverse 。如果緩慢加熱，則以相反的方式發(fā)生這種轉(zhuǎn)化。However, when alloys are cooled rapidly, entirely different results may be obtained, because sufficient time is not provided for the normal phase reactions to occur, in such cases, the phase diagram is no longer a useful tool for engineering ，當(dāng)快速冷卻合金時(shí)，可能得到完全不同的結(jié)果。因?yàn)闆]有足夠的時(shí)間讓正常的狀態(tài)反應(yīng)發(fā)生，在這種情況下對(duì)工程分析而言狀態(tài)圖不再是有用的工具。Hardening 淬火Hardening is the process of heating a piece of steel to a temperature within or above its critical range and then cooling it ，然后使其快速冷卻的過程。If the carbon content of the steel is known, the proper temperature to which the steel should be heated may be obtained by reference to the ironironcarbide phase , if the position of the steel is unknown, a little preliminary experimentation may be necessa