摘 要
鎳基高溫合金、鈦合金、不銹鋼是難加工金屬材料，在航空、航天、能源、化工等工業(yè)部門獲得了廣泛的應用，是國防和經濟建設中不可缺少的重要材料。它們在切磨削加工中具有切削力大、加工硬化傾向嚴重，切削溫度高等特點，加工中產生很大的熱量，造成刀具的磨損、變形，工件表面組織的發(fā)熱變形以及組織成分的改變等等，這都會影響到材料的性能。因此，尋求一種改善生產環(huán)境的綠色切削冷卻方式就顯得尤為重要。傳統(tǒng)切削冷卻加工方法常使用含硫、氯、磷等添加元素的極壓切削液，這種冷卻液污染環(huán)境、危害工人的健康，而水蒸汽作冷卻潤滑劑，腀@浞址⒒悠⒁毫較嗌淞髕扔肴蠡撓攀?，使冷却润滑綑嵞传葻狍滑强嚘得以发粰熏获得琢`訓那炕淙慈蠡Ч且恢致躺?、无污缺M⒏咝У那邢骼淙慈蠡椒?，具有廉价、硒庁时K撓諾?。籍此，本论昔[饕雋艘韻鹿ぷ鰨�
1.本文探討了水蒸汽作冷卻潤滑劑的作用機理，得出：水蒸汽作冷卻潤滑劑是以氣相填充毛細管，取消了液相的滲入和蒸發(fā)階段，大大縮短了填充毛細管的時間，提高了滲透性；又由于水蒸汽中的水分子及氧原子在毛細管部位產生了吸附，在新鮮的刀—屑表面上發(fā)生了化學反應，形成了具有減摩抗磨作用的氧化膜，水蒸汽起到的潤滑作用從而減弱了刀屑間的摩擦。
2.研制和改進了水蒸汽發(fā)生系統(tǒng)，該系統(tǒng)包括水蒸汽發(fā)生器、溫控系統(tǒng)、水蒸汽再加熱裝置、壓力調節(jié)裝置。從而得到了一個自動化程度更高、能夠產生各種溫度水蒸汽的水蒸汽發(fā)生系統(tǒng)。
3.應用有限元仿真軟件Deform-2D進行了GH4169鎳基高溫合金、TC4鈦合金、Cr12不銹鋼正交切削的有限元模擬，著重考察了傳熱系數(shù)的改變對難加工金屬材料切削性能的影響。仿真結果表明：本研究采用的水蒸氣作冷卻潤滑劑的切削技術相對于其它冷卻方式有著顯的優(yōu)越性，且傳熱系數(shù)越大，對切削區(qū)降溫效果越明顯。本文同時還進行了不同金屬材料在其它切削參數(shù)不變的情況下，只改變傳熱系數(shù)進行有限元仿真切削的單因素研究。仿真結果表明：在不同的試件端面溫度下，都有其相應的最佳冷卻潤滑方式，并且隨著材料切削性能的降低，傳熱系數(shù)的變化對切削區(qū)刀具最高溫度和平均溫度的影響增大；材料相對加工性 值越小，傳熱系數(shù)越大，對切削區(qū)的冷卻效果越好。
4.用硬質合金刀具YT15對GH4169、TC4和Cr12進行了切削力、切削溫度實驗，研究在不同的切削參數(shù)下，GH4169、TC4、Cr12的切削力、切削溫度變化規(guī)律，其結論為：水蒸汽作冷卻潤滑劑時主切削力 可比干切、蒸餾水及乳化液時分別減小約30%、25%及20%。

關鍵詞 難加工金屬材料；水蒸汽；綠色切削；切削力；切削溫度；有限元

Abstract
Ni-based superalloy, titanium alloy, stainless steel which is difficult-to-cut metal materials, have gained a wide range of applications in aviation, aerospace, energy, chemical and industry field, is an important and indispensable materials for national defense and economic construction. They have characters of big cutting force, serious work hardening, high cutting temperature and heavy heat in the cutting process, which will cause cutting-tool wear, deformation, heating and deformation of the sample surface and the changing of the structure, all of which influence property of the material. So it is very important to seek a green cooling manner which will use new technology and improve production environment. The conventional method is usually used to the excellent cutting fluid with the agent for sulfur, chlorine and phosphor element, however, the reactant and excrement will pollute the environment and harm to operator, the cutting technoloy that water vapor is used as coolats and lubricants includes cryogenic gas-liquid two phrase flow and full vaporization to enhance the heat transfer potential of cooling medium and obtain the best cooling and lubricanting effect, so it is a green, no-pollution and high efficiency cooling and lubricanting method, which has the advantages of cheap and no recovery. Based on it, this thesis mainly do the following job:
1. The paper discusses the mechanism of water vapor is used as coolants and lubricants and obtains that water vapor is used as coolants and lubricants fills capillary with gas. Because of removing the stage of liquid infiltration and evaporation,it greatly reduce the time of filling capillary and raises the permeability of water vapor. And because the water molecules and oxygen atoms of water vapor which generate adsorption in capillary wall, it produces chemical reactions in fresh Tool-chip surface and reducing friction and resisting wear of oxide film. Apparently, it is a effection that water vapor generates lubricants. The jet of water vapor has a strong heat-transfer capacity, which is the direct cooling effect of water vapor.
2. The paper rebuild and improve the experimental system, including the occurring system of water vapor, the controling system of temperature, the re-heating device of water vapor and the regulating device of pressure, and get a higher automatically generating system of water vapor which can produce all sorts of temperature water vapor.
3. Used the finite element software Deform-2D, the paper simulating the orthogonal cutting process of superalloy(GH4169), titanium alloy(TC4), stainless steel(Cr12), discussed the cutting performance on the effect of change the heat exchange coefficient. The result of simulation indicates that, the method of water vapor is used as coolats and lubricants which used in the paper ..