液壓卷花機
液壓卷花機,液壓,卷花機
攀枝花學院畢業(yè)設計（論文） 摘要 I 摘 要 本次畢業(yè)設計題目是液壓卷花系統(tǒng)設計。任務限制只能用液壓來實現。本 人致力于整機系統(tǒng)的設計，即機械結構的設計，液壓系統(tǒng)方案的擬定，液壓油 箱的設計，液壓缸的設計，液壓站的設計。設計思路是從卷花機的性能和動作 要求入手，并以國內的質量和技術性能接近設計要求的卷花機為基礎，研究國 外的先進機型，開發(fā)出自己的全套液壓系統(tǒng)方案。圖紙采用 Auto CAD 繪制。 經過認真地設計計算,查找資料撰寫設計論文。 本液壓卷花機的優(yōu)點是傳動平穩(wěn)，輸出力矩大，用模具來實現花形的變化， 且同一批形狀的一致性好，液壓機造型美觀。設計出來的液壓卷花系統(tǒng)具有， 尺寸精確，生產效率高，勞動強度低，產品質量好的優(yōu)點。廣泛應用于鐵藝行 業(yè)中。由該機器生產的各種花形可用在圍欄、大門、臺、椅、扶梯、窗、招牌、 藝術品等制作的地方。 關鍵詞 液壓卷花機，液壓系統(tǒng)，鐵藝 攀枝花學院畢業(yè)設計（論文） ABSTRACT II ABSTRACT My graduation project topic is the Volume hydraulic system design. The duty limit only uses the hydraulic pressure to realize. I have carried on the whole design， namely, the mechanism design, hydraulic system plan drawing up, the hydraulic fluid tank design, the hydraulic cylinder design, the hydraulic pressure stands design and so on. The design start at the volume flower's machine performance and the movement, taking the home existing volume flower machine as the foundation, their quality and the technical performance approach to this design request, and has studied the overseas advanced type, developed own complete set hydraulic system plan. The blueprint draws up with Auto CAD. After earnestly calculated, has consulted the correlation data, I have composed this design paper. The volume flower's machine merit is the transmission steady, out put moment of force big, realizes the flowered shape change with the mold, also identical batch of product uniformity good, the volume flower's machine Modeling is artistic. The system of the volume flower’s machine has the merit, such as, size precisely, the production efficiency high, the labor intensity is low, the product quality is good and so on. This machine is widely applied in the steel art profession, and can product several kinds of flowers for fences, gates, place, chairs, elevator, windows, signs, art and so on. Key words volume hydraulic machine， hydraulic system，steel art 攀枝花學院畢業(yè)設計（論文） 目錄 目 錄 摘 要 ............................................................................................................................I ABSTRACT................................................................................................................II 1 緒論 ..........................................................................................................................1 1.1 本課題研究的目的意義 ...........................................................................................1 1.2 本課題國內外發(fā)展概況及存在的問題 ......................................................................1 1.3 本課題解決的主要問題 ...........................................................................................2 2 液壓卷花機系統(tǒng)分析與設計 ..................................................................................3 2.1 設計思想 ................................................................................................................3 2.2 液壓卷花機系統(tǒng)分析 ...............................................................................................3 2.2.1 本機設計要求及具體的技術參數 ......................................................................3 2.2.2 卷花機的液壓系統(tǒng) ...........................................................................................3 2.2.3 液壓卷花機系統(tǒng)方案的比較與選用 ..................................................................3 3 液壓系統(tǒng)的計算 ........................................................................................................7 3.1 彎矩力的計算 .........................................................................................................7 3.1.1 材料力學的角度 ...............................................................................................7 3.1.2 采用類比法 ....................................................................................................10 3.2 齒輪齒條傳動設計 .................................................................................................11 3.3 載荷組成和計算 ....................................................................................................13 3.4 卷花機液壓系統(tǒng)設計 .............................................................................................16 3.4.1 負載分析 ........................................................................................................16 3.4.2 初選液壓系統(tǒng)工作壓力 ...................................................................................16 3.4.3 液壓缸的類型及安裝方式 ...............................................................................16 3.4.4 液壓缸的主要結構尺寸 ...................................................................................16 3.4.5 壓桿穩(wěn)定性驗算 .............................................................................................17 3.4.6 按最低速度要求驗算液壓缸尺寸 .....................................................................18 3.4.7 計算液壓缸所需流量 ......................................................................................18 3.4.8 繪制液壓系統(tǒng)工況圖 ......................................................................................19 3.4.9 制定基本方案確定液壓系統(tǒng)原理圖 .................................................................21 3.5 液壓系統(tǒng)的計算和選擇液壓元件 ............................................................................22 3.5.1 確定液壓泵的流量、壓力和選擇泵的規(guī)格 .......................................................22 攀枝花學院畢業(yè)設計（論文） 目錄 3.5.2 液壓閥的選擇和部分液壓輔助元件選擇 ..........................................................24 3.5.3 油箱容量的初步確定及油液的選擇 .................................................................27 3.6 液壓系統(tǒng)性能驗算 .................................................................................................28 3.6.1 壓力損失及調定壓力的確定 ............................................................................28 3.6.2 系統(tǒng)溫升驗算 .................................................................................................30 4 液壓缸的設計 ..........................................................................................................32 4.1 選擇液壓缸類型安裝方式 ......................................................................................32 4.2 液壓缸的主要性能參數和主要尺寸 ........................................................................32 4.3 液壓缸的參數計算 .................................................................................................32 4.3.1 缸筒壁厚的計算 .............................................................................................32 4.3.2 液壓缸活塞行程 .............................................................................................33 4.3.3 液壓缸油口直徑計算 ......................................................................................33 4.3.4 缸底厚度計算 .................................................................................................33 4.3.5 缸頭厚度計算 .................................................................................................34 4.3.6 最小導向長度的計算 ......................................................................................34 4.3.7 缸體長度的確定 .............................................................................................34 4.4 活塞的設計 ...........................................................................................................35 4.4.1 活塞的結構形式 .............................................................................................35 4.4.2 活塞與活塞桿的連接 ......................................................................................35 4.4.3 活塞的密封 ....................................................................................................36 4.4.4 活塞材料 ........................................................................................................39 4.4.5 活塞尺寸及加工公差 ......................................................................................39 4.5 活塞桿 ..................................................................................................................39 4.6 活塞桿的導向套、密封和防塵 ...............................................................................40 4.7 液壓缸緩沖裝置的設計 ..........................................................................................41 4.7.1 間隙緩沖 ........................................................................................................41 4.7.2 閥式緩沖 ........................................................................................................41 4.8 排氣閥 ..................................................................................................................42 5 液壓站的設計 ........................................................................................................44 5.1 確定液壓站的結構類型方案 ...................................................................................44 5.1.1 分散配置型液壓裝置 ......................................................................................44 5.1.2 集中配置型液壓裝置 ......................................................................................44 5.1.3 確定液壓站的方案 ..........................................................................................44 5.2 液壓控制裝置（液壓閥站的集成設計） .................................................................44 攀枝花學院畢業(yè)設計（論文） 目錄 5.2.1 有管集成 ........................................................................................................45 5.2.2 無管集成 ........................................................................................................45 5.2.3 確定液壓控制裝置 ..........................................................................................45 5.3 液壓動力源裝置（液壓泵站）的設計 .....................................................................47 5.3.1 液壓泵組布 置方式的確定 ...............................................................................47 5.3.2 液壓油箱的設計 ............................................................................................48 5.4 液壓泵組的結構設計 .............................................................................................54 5.4.1 液壓泵組的布置方式 ......................................................................................54 5.4.2 液壓泵組的連接和安裝方式 ...........................................................................54 5.5 液壓站的結構總成 .................................................................................................55 5.5.1 管路的選擇 ....................................................................................................55 5.5.2 電氣控制裝置的設計與布置 ............................................................................55 5.6 液壓站總圖的設計與繪制 ......................................................................................56 6 機械結構的設計 ....................................................................................................57 6.1 齒輪齒條傳動設計 .................................................................................................57 6.2 軸的設計 ...............................................................................................................57 6.2.1 求輸出軸上的功率 P,轉速 n 和轉矩 T..............................................................57 6.2.2 求作用在齒輪上的力 ......................................................................................57 6.2.3 初步確定軸的最小直徑 ...................................................................................57 6.2.4 軸的結構設計 .................................................................................................57 6.3 求軸上載荷 ...........................................................................................................60 6.4 按彎扭合成應力校核軸的強度 ...............................................................................61 6.5 卷花機的內部結構示意圖 ......................................................................................62 結 論 ..........................................................................................................................63 參 考 文 獻 ................................................................................................................64 致 謝 ........................................................................................................................65 攀枝花學院畢業(yè)設計（論文） 目錄 1 緒論 1.1 本課題研究的目的意義 液壓卷花機是一種利用液體壓力來傳遞能量，以實現各種壓力加工工藝的 機床。由該機器生產的各種花形可用在圍欄，大門，臺，椅，扶梯，窗，招牌， 藝術品等地方。隨著人民生活水平提高，這些鐵藝制品必然會有較大需求。另 一方面，用液壓來實現，能滿足用戶任意設計的圖案，效率高，花形同一性好， 體積小，重量輕，功能多，施工方便，勞動強度輕，隨著新工藝及新技術的應 用，卷花機在金屬加工及非金屬成形方面的應用越來越廣泛，在鐵藝行業(yè)中的 占有份額正在大幅度攀升。 1.2 本課題國內外發(fā)展概況及存在的問題 目前，用來制作卷花的設備還非常落后，按動力的來源角度，大體分為四 種方式來實現：一、采用手工。該方法一般為小作坊生產，批量不大，生產效 率低，但也能滿足個性化的需要，因為它可任意改變花形，但勞動強度高。代 表型號有北京光大利克經貿有限責任公司生產的手動式鐵藝軋花工裝設備。二、 采用機械方式來實現。效率有所提高，但制作了的花形的尺寸有限，主要是受 動力的限制。噪聲大，能耗大，不能完全滿足市場需求。代表型號有石家莊安 邦機械公司的電動卷花機, AB-DW10A, AB-DW10B; 東北林業(yè)大學機械廠的萬能 鐵藝成形機;寧夏富盛機械制造有限公司的電動金屬扭曲機。三、采用鍛造方式。 鍛造方式來實現的，材料局限性較大，不能用厚板，也加工不出開關復雜的尾 部曲卷，效率不高。代表型號有廣州郎亞公司的鍛鐵液壓裝置。四、采用液壓 來實現。采用該方式的優(yōu)點比較明顯在，下面將要介紹。在鐵藝行業(yè)市場中， 它們四種方式對應對的裝備的使用比例大概為2：4：3：1；可見,使用機械方式 來加工的占了大多數，使用液壓的較少。 在總結目前國內外卷花機的發(fā)展現狀以及今后的發(fā)展趨勢的情況下，當前 卷花機還有著以下的幾點不足：1、能耗較大，不夠環(huán)?！，F在有的卷花機的能 源利用率不能，僅有 50%左右，因為主要是采用的是機械方式作為動力，熱損 耗較大。不符合當今提倡的節(jié)約型社會的要求。而且，機械方式的噪音較大， 對工人及周邊的損害也嚴重，不人性化。2、卷花機體積大,占地面積較多。對 企業(yè)來說不是一件好事。3、加工的料的尺寸有限，花形較少。這主要受動力的 限制。不能完全滿足當前的市場需求,在模具上,也可在進行改進。 4、自動化 程度不高，生產率也就不高。5、現在使用的模具較復雜。 攀枝花學院畢業(yè)設計（論文） 目錄 1.3 本課題解決的主要問題 設計出的卷花機能滿足當前市場的需要。有效地規(guī)避了當前卷花機的不足。 采用液壓力傳動來代替機械傳動，并且用模具來實現花形的變化。采用液壓液 壓傳動能有效地克服，上面所說的不足，并且傳動平穩(wěn)，出力較大，從整體來 看單位體積的出力比機械的傳動方式大得多，體積小。采用模具來加工，在需 要改變花形時，只需要改變模具的形狀即可，擴充了機器的加工范圍，且又能 很好地保證同一批產品形狀的一致性。設計出來的液壓卷花系統(tǒng)具有，尺寸精 確，生產效率高，勞動強度低，產品質量好的優(yōu)點。
外文譯文
院 （系）： 機電工程學院
專 業(yè)： 機械設計制造及其自動化
姓 名：
學 號： ZJD02043
指導教師評語：
簽名：
年 月 日
外語文獻翻譯
摘自: 《制造工程與技術（機加工）》（英文版）
《Manufacturing Engineering and Technology—Machining》
機械工業(yè)出版社 2004年3月第1版
美 s. 卡爾帕基安(Serope kalpakjian)
s.r 施密德(Steven R.Schmid) 著
原文：
20.9 MACHINABILITY
The machinability of a material usually defined in terms of four factors:
1、 Surface finish and integrity of the machined part;
2、 Tool life obtained;
3、 Force and power requirements;
4、 Chip control.
Thus, good machinability good surface finish and integrity, long tool life, and low force And power requirements. As for chip control, long and thin (stringy) cured chips, if not broken up, can severely interfere with the cutting operation by becoming entangled in the cutting zone.
Because of the complex nature of cutting operations, it is difficult to establish relationships that quantitatively define the machinability of a material. In manufacturing plants, tool life and surface roughness are generally considered to be the most important factors in machinability. Although not used much any more, approximate machinability ratings are available in the example below.
20.9.1 Machinability Of Steels
Because steels are among the most important engineering materials (as noted in Chapter 5), their machinability has been studied extensively. The machinability of steels has been mainly improved by adding lead and sulfur to obtain so-called free-machining steels.
Resulfurized and Rephosphorized steels. Sulfur in steels forms manganese sulfide inclusions (second-phase particles), which act as stress raisers in the primary shear zone. As a result, the chips produced break up easily and are small; this improves machinability. The size, shape, distribution, and concentration of these inclusions significantly influence machinability. Elements such as tellurium and selenium, which are both chemically similar to sulfur, act as inclusion modifiers in resulfurized steels.
Phosphorus in steels has two major effects. It strengthens the ferrite, causing increased hardness. Harder steels result in better chip formation and surface finish. Note that soft steels can be difficult to machine, with built-up edge formation and poor surface finish. The second effect is that increased hardness causes the formation of short chips instead of continuous stringy ones, thereby improving machinability.
Leaded Steels. A high percentage of lead in steels solidifies at the tip of manganese sulfide inclusions. In non-resulfurized grades of steel, lead takes the form of dispersed fine particles. Lead is insoluble in iron, copper, and aluminum and their alloys. Because of its low shear strength, therefore, lead acts as a solid lubricant (Section 32.11) and is smeared over the tool-chip interface during cutting. This behavior has been verified by the presence of high concentrations of lead on the tool-side face of chips when machining leaded steels.
When the temperature is sufficiently high-for instance, at high cutting speeds and feeds (Section 20.6)—the lead melts directly in front of the tool, acting as a liquid lubricant. In addition to this effect, lead lowers the shear stress in the primary shear zone, reducing cutting forces and power consumption. Lead can be used in every grade of steel, such as 10xx, 11xx, 12xx, 41xx, etc. Leaded steels are identified by the letter L between the second and third numerals (for example, 10L45). (Note that in stainless steels, similar use of the letter L means “l(fā)ow carbon,” a condition that improves their corrosion resistance.)
However, because lead is a well-known toxin and a pollutant, there are serious environmental concerns about its use in steels (estimated at 4500 tons of lead consumption every year in the production of steels). Consequently, there is a continuing trend toward eliminating the use of lead in steels (lead-free steels). Bismuth and tin are now being investigated as possible substitutes for lead in steels.
Calcium-Deoxidized Steels. An important development is calcium-deoxidized steels, in which oxide flakes of calcium silicates (CaSo) are formed. These flakes, in turn, reduce the strength of the secondary shear zone, decreasing tool-chip interface and wear. Temperature is correspondingly reduced. Consequently, these steels produce less crater wear, especially at high cutting speeds.
Stainless Steels. Austenitic (300 series) steels are generally difficult to machine. Chatter can be s problem, necessitating machine tools with high stiffness. However, ferritic stainless steels (also 300 series) have good machinability. Martensitic (400 series) steels are abrasive, tend to form a built-up edge, and require tool materials with high hot hardness and crater-wear resistance. Precipitation-hardening stainless steels are strong and abrasive, requiring hard and abrasion-resistant tool materials.
The Effects of Other Elements in Steels on Machinability. The presence of aluminum and silicon in steels is always harmful because these elements combine with oxygen to form aluminum oxide and silicates, which are hard and abrasive. These compounds increase tool wear and reduce machinability. It is essential to produce and use clean steels.
Carbon and manganese have various effects on the machinability of steels, depending on their composition. Plain low-carbon steels (less than 0.15% C) can produce poor surface finish by forming a built-up edge. Cast steels are more abrasive, although their machinability is similar to that of wrought steels. Tool and die steels are very difficult to machine and usually require annealing prior to machining. Machinability of most steels is improved by cold working, which hardens the material and reduces the tendency for built-up edge formation.
Other alloying elements, such as nickel, chromium, molybdenum, and vanadium, which improve the properties of steels, generally reduce machinability. The effect of boron is negligible. Gaseous elements such as hydrogen and nitrogen can have particularly detrimental effects on the properties of steel. Oxygen has been shown to have a strong effect on the aspect ratio of the manganese sulfide inclusions; the higher the oxygen content, the lower the aspect ratio and the higher the machinability.
In selecting various elements to improve machinability, we should consider the possible detrimental effects of these elements on the properties and strength of the machined part in service. At elevated temperatures, for example, lead causes embrittlement of steels (liquid-metal embrittlement, hot shortness; see Section 1.4.3), although at room temperature it has no effect on mechanical properties.
Sulfur can severely reduce the hot workability of steels, because of the formation of iron sulfide, unless sufficient manganese is present to prevent such formation. At room temperature, the mechanical properties of resulfurized steels depend on the orientation of the deformed manganese sulfide inclusions (anisotropy). Rephosphorized steels are significantly less ductile, and are produced solely to improve machinability.
20.9.2 Machinability of Various Other Metals
Aluminum is generally very easy to machine, although the softer grades tend to form a built-up edge, resulting in poor surface finish. High cutting speeds, high rake angles, and high relief angles are recommended. Wrought aluminum alloys with high silicon content and cast aluminum alloys may be abrasive; they require harder tool materials. Dimensional tolerance control may be a problem in machining aluminum, since it has a high thermal coefficient of expansion and a relatively low elastic modulus.
Beryllium is similar to cast irons. Because it is more abrasive and toxic, though, it requires machining in a controlled environment.
Cast gray irons are generally machinable but are. Free carbides in castings reduce their machinability and cause tool chipping or fracture, necessitating tools with high toughness. Nodular and malleable irons are machinable with hard tool materials.
Cobalt-based alloys are abrasive and highly work-hardening. They require sharp, abrasion-resistant tool materials and low feeds and speeds.
Wrought copper can be difficult to machine because of built-up edge formation, although cast copper alloys are easy to machine. Brasses are easy to machine, especially with the addition pf lead (leaded free-machining brass). Bronzes are more difficult to machine than brass.
Magnesium is very easy to machine, with good surface finish and prolonged tool life. However care should be exercised because of its high rate of oxidation and the danger of fire (the element is pyrophoric).
Molybdenum is ductile and work-hardening, so it can produce poor surface finish. Sharp tools are necessary.
Nickel-based alloys are work-hardening, abrasive, and strong at high temperatures. Their machinability is similar to that of stainless steels.
Tantalum is very work-hardening, ductile, and soft. It produces a poor surface finish; tool wear is high.
Titanium and its alloys have poor thermal conductivity (indeed, the lowest of all metals), causing significant temperature rise and built-up edge; they can be difficult to machine.
Tungsten is brittle, strong, and very abrasive, so its machinability is low, although it greatly improves at elevated temperatures.
Zirconium has good machinability. It requires a coolant-type cutting fluid, however, because of the explosion and fire.
20.9.3 Machinability of Various Materials
Graphite is abrasive; it requires hard, abrasion-resistant, sharp tools.
Thermoplastics generally have low thermal conductivity, low elastic modulus, and low softening temperature. Consequently, machining them requires tools with positive rake angles (to reduce cutting forces), large relief angles, small depths of cut and feed, relatively high speeds, and
proper support of the workpiece. Tools should be sharp.
External cooling of the cutting zone may be necessary to keep the chips from becoming “gummy” and sticking to the tools. Cooling can usually be achieved with a jet of air, vapor mist, or water-soluble oils. Residual stresses may develop during machining. To relieve these stresses, machined parts can be annealed for a period of time at temperatures ranging from to (to), and then cooled slowly and uniformly to room temperature.
Thermosetting plastics are brittle and sensitive to thermal gradients during cutting. Their machinability is generally similar to that of thermoplastics.
Because of the fibers present, reinforced plastics are very abrasive and are difficult to machine. Fiber tearing, pulling, and edge delamination are significant problems; they can lead to severe reduction in the load-carrying capacity of the component. Furthermore, machining of these materials requires careful removal of machining debris to avoid contact with and inhaling of the fibers.
The machinability of ceramics has improved steadily with the development of nanoceramics (Section 8.2.5) and with the selection of appropriate processing parameters, such as ductile-regime cutting (Section 22.4.2).
Metal-matrix and ceramic-matrix composites can be difficult to machine, depending on the properties of the individual components, i.e., reinforcing or whiskers, as well as the matrix material.
20.9.4 Thermally Assisted Machining
Metals and alloys that are difficult to machine at room temperature can be machined more easily at elevated temperatures. In thermally assisted machining (hot machining), the source of heat—a torch, induction coil, high-energy beam (such as laser or electron beam), or plasma arc—is forces, (b) increased tool life, (c) use of inexpensive cutting-tool materials, (d) higher material-removal rates, and (e) reduced tendency for vibration and chatter.
It may be difficult to heat and maintain a uniform temperature distribution within the workpiece. Also, the original microstructure of the workpiece may be adversely affected by elevated temperatures. Most applications of hot machining are in the turning of high-strength metals and alloys, although experiments are in progress to machine ceramics such as silicon nitride.
SUMMARY
Machinability is usually defined in terms of surface finish, tool life, force and power requirements, and chip control. Machinability of materials depends not only on their intrinsic properties and microstructure, but also on proper selection and control of process variables.
譯文：
20.9 可機加工性
一種材料的可機加工性通常以四種因素的方式定義：
1、 分的表面光潔性和表面完整性。
2、刀具的壽命。
3、切削力和功率的需求。
4、切屑控制。
以這種方式，好的可機加工性指的是好的表面光潔性和完整性，長的刀具壽命，低的切削力和功率需求。關于切屑控制，細長的卷曲切屑，如果沒有被切割成小片，以在切屑區(qū)變的混亂，纏在一起的方式能夠嚴重的介入剪切工序。
因為剪切工序的復雜屬性，所以很難建立定量地釋義材料的可機加工性的關系。在制造廠里，刀具壽命和表面粗糙度通常被認為是可機加工性中最重要的因素。盡管已不再大量的被使用，近乎準確的機加工率在以下的例子中能夠被看到。
20.9.1 鋼的可機加工性
因為鋼是最重要的工程材料之一（正如第5章所示），所以他們的可機加工性已經被廣泛地研究過。通過宗教鉛和硫磺，鋼的可機加工性已經大大地提高了。從而得到了所謂的易切削鋼。
二次硫化鋼和二次磷化鋼 硫在鋼中形成硫化錳夾雜物（第二相粒子），這些夾雜物在第一剪切區(qū)引起應力。其結果是使切屑容易斷開而變小，從而改善了可加工性。這些夾雜物的大小、形狀、分布和集中程度顯著的影響可加工性。化學元素如碲和硒，其化學性質與硫類似，在二次硫化鋼中起夾雜物改性作用。
鋼中的磷有兩個主要的影響。它加強鐵素體，增加硬度。越硬的鋼，形成更好的切屑形成和表面光潔性。需要注意的是軟鋼不適合用于有積屑瘤形成和很差的表面光潔性的機器。第二個影響是增加的硬度引起短切屑而不是不斷的細長的切屑的形成，因此提高可加工性。
含鉛的鋼 鋼中高含量的鉛在硫化錳夾雜物尖端析出。在非二次硫化鋼中，鉛呈細小而分散的顆粒。鉛在鐵、銅、鋁和它們的合金中是不能溶解的。因為它的低抗剪強度。因此，鉛充當固體潤滑劑并且在切削時，被涂在刀具和切屑的接口處。這一特性已經被在機加工鉛鋼時，在切屑的刀具面表面有高濃度的鉛的存在所證實。
當溫度足夠高時—例如，在高的切削速度和進刀速度下—鉛在刀具前直接熔化，并且充當液體潤滑劑。除了這個作用，鉛降低第一剪切區(qū)中的剪應力，減小切削力和功率消耗。鉛能用于各種鋼號，例如10XX，11XX，12XX，41XX等等。鉛鋼被第二和第三數碼中的字母L所識別（例如，10L45）。（需要注意的是在不銹鋼中，字母L的相同用法指的是低碳，提高它們的耐蝕性的條件）。
然而，因為鉛是有名的毒素和污染物，因此在鋼的使用中存在著嚴重的環(huán)境隱患（在鋼產品中每年大約有4500噸的鉛消耗）。結果，對于估算鋼中含鉛量的使用存在一個持續(xù)的趨勢。鉍和錫現正作為鋼中的鉛最可能的替代物而被人們所研究。
脫氧鈣鋼 一個重要的發(fā)展是脫氧鈣鋼，在脫氧鈣鋼中矽酸鈣鹽中的氧化物片的形成。這些片狀，依次減小第二剪切區(qū)中的力量，降低刀具和切屑接口處的摩擦和磨損。溫度也相應地降低。結果，這些鋼產生更小的月牙洼磨損，特別是在高切削速度時更是如此。
不銹鋼 奧氏體鋼通常很難機加工。振動能成為一個問題，需要有高硬度的機床。然而，鐵素體不銹鋼有很好的可機加工性。馬氏體鋼易磨蝕，易于形成積屑瘤，并且要求刀具材料有高的熱硬度和耐月牙洼磨損性。經沉淀硬化的不銹鋼強度高、磨蝕性強，因此要求刀具材料硬而耐磨。
鋼中其它元素在可機加工性方面的影響 鋼中鋁和矽的存在總是有害的，因為這些元素結合氧會生成氧化鋁和矽酸鹽，而氧化鋁和矽酸鹽硬且具有磨蝕性。這些化合物增加刀具磨損，降低可機加工性。因此生產和使用凈化鋼非常必要。
根據它們的構成，碳和錳鋼在鋼的可機加工性方面有不同的影響。低碳素鋼（少于0.15%的碳）通過形成一個積屑瘤能生成很差的表面光潔性。盡管鑄鋼的可機加工性和鍛鋼的大致相同，但鑄鋼具有更大的磨蝕性。刀具和模具鋼很難用于機加工，他們通常再煅燒后再機加工。大多數鋼的可機加工性在冷加工后都有所提高，冷加工能使材料變硬并且減少積屑瘤的形成。
其它合金元素，例如鎳、鉻、鉗和釩，能提高鋼的特性，減小可機加工性。硼的影響可以忽視。氣態(tài)元素比如氫和氮在鋼的特性方面能有特別的有害影響。氧已經被證明了在硫化錳夾雜物的縱橫比方面有很強的影響。越高的含氧量，就產生越低的縱橫比和越高的可機加工性。
選擇各種元素以改善可加工性，我們應該考慮到這些元素對已加工零件在使用中的性能和強度的不利影響。例如，當溫度升高時，鋁會使鋼變脆（液體—金屬脆化，熱脆化，見1.4.3節(jié)），盡管其在室溫下對力學性能沒有影響。
因為硫化鐵的構成，硫能嚴重的減少鋼的熱加工性，除非有足夠的錳來防止這種結構的形成。在室溫下，二次磷化鋼的機械性能依賴于變形的硫化錳夾雜物的定位（各向異性）。二次磷化鋼具有更小的延展性，被單獨生成來提高機加工性。
20.9.2 其它不同金屬的機加工性
盡管越軟的品種易于生成積屑瘤，但鋁通常很容易被機加工，導致了很差的表面光潔性。高的切削速度，高的前角和高的后角都被推薦了。有高含量的矽的鍛鋁合金鑄鋁合金也許具有磨蝕性，它們要求更硬的刀具材料。尺寸公差控制也許在機加工鋁時會成為一個問題，因為它有膨脹的高導熱系數和相對低的彈性模數。
鈹和鑄鐵相同。因為它更具磨蝕性和毒性，盡管它要求在可控人工環(huán)境下進行機加工。
灰鑄鐵普遍地可加工，但也有磨蝕性。鑄造無中的游離碳化物降低它們的可機加工性，引起刀具切屑或裂口。它需要具有強韌性的工具。具有堅硬的刀具材料的球墨鑄鐵和韌性鐵是可加工的。
鈷基合金有磨蝕性且高度加工硬化的。它們要求尖的且具有耐蝕性的刀具材料并且有低的走刀和速度。
盡管鑄銅合金很容易機加工，但因為鍛銅的積屑瘤形成因而鍛銅很難機加工。黃銅很容易機加工，特別是有添加的鉛更容易。青銅比黃銅更難機加工。
鎂很容易機加工，鎂既有很好的表面光潔性和長久的刀具壽命。然而，因為高的氧化速度和火種的危險（這種元素易燃），因此我們應該特別小心使用它。
鉗易拉長且加工硬化，因此它生成很差的表面光潔性。尖的刀具是很必要的。
鎳基合金加工硬化，具有磨蝕性，且在高溫下非常堅硬。它的可機加工性和不銹鋼相同。
鉭非常的加工硬化，具有可延性且柔軟。它生成很差的表面光潔性且刀具磨損非常大。
鈦和它的合金導熱性(的確，是所有金屬中最低的)，因此引起明顯的溫度升高和積屑瘤。它們是難機加工的。
鎢易脆，堅硬，且具有磨蝕性，因此盡管它的性能在高溫下能大大提高，但它的機加工性仍很低。
鋯有很好的機加工性。然而，因為有爆炸和火種的危險性，它要求有一個冷卻性質好的切削液。
20.9.3 各種材料的機加工性
石墨具有磨蝕性。它要求硬的、尖的，具有耐蝕性的刀具。
塑性塑料通常有低的導熱性，低的彈性模數和低的軟化溫度。因此，機加工熱塑性塑料要求有正前角的刀具（以此降低切削力），還要求有大的后角，小的切削和走刀深的，相對高的速度和工件的正確支承。刀具應該很尖。
切削區(qū)的外部冷卻也許很必要，以此來防止切屑變的有黏性且粘在刀具上。有了空氣流，汽霧或水溶性油，通常就能實現冷卻。在機加工時，殘余應力也許能生成并發(fā)展。為了解除這些力，已機加工的部分要在（）的溫度范圍內冷卻一段時間，然而慢慢地無變化地冷卻到室溫。
熱固性塑料易脆，并且在切削時對熱梯度很敏感。它的機加工性和熱塑性塑料的相同。
因為纖維的存在，加強塑料具有磨蝕性，且很難機加工。纖維的撕裂、拉出和邊界分層是非常嚴重的問題。它們能導致構成要素的承載能力大大下降。而且，這些材料的機加工要求對加工殘片仔細切除，以此來避免接觸和吸進纖維。
隨著納米陶瓷（見8.2.5節(jié)）的發(fā)展和適當的參數處理的選擇，例如塑性切削（見22.4.2節(jié)），陶瓷器的可機加工性已大大地提高了。
金屬基復合材料和陶瓷基復合材料很能機加工，它們依賴于單獨的成分的特性，比如說增強纖維或金屬須和基體材料。
20.9.4 熱輔助加工
在室溫下很難機加工的金屬和合金在高溫下能更容易地機加工。在熱輔助加工時（高溫切削），熱源—一個火把，感應線圈，高能束流（例如雷射或電子束），或等離子弧—被集中在切削刀具前的一塊區(qū)域內。好處是：（a）低的切削力。（b）增加的刀具壽命。（c）便宜的切削刀具材料的使用。（d）更高的材料切除率。（e）減少振動。
也許很難在工件內加熱和保持一個不變的溫度分布。而且，工件的最初微觀結構也許被高溫影響，且這種影響是相當有害的。盡管實驗在進行中，以此來機加工陶瓷器如氮化矽，但高溫切削仍大多數應用在高強度金屬和高溫度合金的車削中。
小結
通常，零件的可機加工性能是根據以下因素來定義的：表面粗糙度，刀具的壽命，切削力和功率的需求以及切屑的控制。材料的可機加工性能不僅取決于起內在特性和微觀結構，而且也依賴于工藝參數的適當選擇與控制。
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