鋁板帶軋制工藝原理(中英文)

1、 the mechanics of thealuminum sheet rolling process鋁板帶軋制工藝機(jī)理 the mechanics of the aluminum sheet rolling process 鋁板帶軋制工藝機(jī)理 index索引1. preamble導(dǎo)言2. casting2.鑄造 (i) description(i) 描述 (ii) metal filter (ii) 金屬過(guò)濾器 (iii) casting machines (iii) 鑄造機(jī) (iv) continuous casters(iv) 連續(xù)鑄造機(jī)3. scalping3.銑削 (i) surfa

2、ce (i) 表面 (ii) edge (ii) 邊 (iii) head and tails (iii) 頭和尾 4. preheating and homogenizing4.加熱和均熱5. hot lines5. 熱軋線 (i) hot line table geometry (i) 熱軋線輥道幾何學(xué) (ii) configuration (ii) 配置 (iii) hot mill roll roughness(iii) 熱軋機(jī)軋制粗糙度 (iv) roll grinding (iv)磨輥 (v) scratch brushes (v) 鋼絲刷6. hot rolling6.熱軋7.

3、cold rolling7.冷軋 (i) reductions (i) 壓下量 (ii) shape (ii) 形狀 (iii) surface finish (iii) 表面光潔度 fourth annual hiarc meetingoctober 16-18, 1996toronto, canada 第四屆hiarc年會(huì) 1996年10月16日到18日 多倫多，加拿大the mechanism of the aluminum sheet rolling process 鋁板帶軋制工藝機(jī)理1. preamble1. 導(dǎo)言during the rolling of aluminum shee

4、t, particularly hot rolling many problems may arise. there is frequently an initial tendency to ascribe many of these to the coolant. some of the issues in the circumstances are not coolant related. this paper describes the treatment of aluminum from casting to cold rolling in an attempt to give som

5、e insight into the many problems that can arise in the rolling process.鋁板帶軋制過(guò)程中，尤其是熱軋，會(huì)出現(xiàn)很多問(wèn)題。經(jīng)常性的最初傾向是，把這些問(wèn)題的多數(shù)歸因于冷卻液。一些問(wèn)題所處的環(huán)境與冷卻液無(wú)關(guān)此文件描述了從鑄造到冷軋的鋁處理方法，試圖就軋制過(guò)程中可能會(huì)出現(xiàn)的許多問(wèn)題給出一些深刻的見(jiàn)解。 2. casting2.鑄造(i)description(i)描述for the purposes of rolling sheet or plate as opposed to extruding, aluminum is mainl

6、y cast by the v.d.c. or vertical direct chill process which produce large block of up to 30 inches thick suitable for rolling, or to a lesser extent may be produced by continuous casting which makes coil with a metal thickness of between a l/4”to 3/4”.軋制鋁帶材或鋁板的目的，不允許有擠壓，鋁主要是由立式直冷鑄造機(jī)鑄造的，立式直冷鑄造機(jī)可生產(chǎn)適用于

7、軋制厚度達(dá)30英寸的大鋁塊，或在較小程度上也可通過(guò)連續(xù)鑄造生產(chǎn)厚度在l/4到3/4英寸之間的卷材。the molten metal which is used for casting may be any one of series of alloy from 1xxx through 2, 3, 4, 5, 6 to 7xxx. the most common are 1xxxs which are largely pure with minor alloying and are used for foil stock, to 3xxxs used extensively as 3004 f

8、or body stock to 5xxxs as 5182 for can end stock and 5086 as a high tensile sheet. series 2xxx and 6xxx are heat treatable and besides magnesium have higher concentrations of copper. the 7xxx series alloys with significant zinc are used in some places for armour plate.用于鑄造的熔化金屬可以是從1xxx到7xxx的任何一系列合金。

9、最普通的是1xxx系列，它的純度很高、合金很少，被用作鋁箔原料；3xxx系列如3004大量用于罐體坯料 ；5xxx系列如5182用于罐蓋料以及5086用于高強(qiáng)度拉伸板。2xxx和6xxx系列可進(jìn)行熱處理，除了鎂之外，還含較高濃度的銅。7xxx系列含有大量的鋅，用于需要裝甲板的地方。the melting point for most alloys falls within the range 1125 to 1215of 8or 610 to 660oc)大多數(shù)合金的熔點(diǎn)在1125到 1215of 或 610 660oc范圍內(nèi)。during the melting and casting op

10、eration due attention must be paid to two parameters.在熔鑄操作過(guò)程中必須關(guān)注兩個(gè)參數(shù)。l hydrogenl 氫 firstly hydrogen which is absorbed by the metal with increased solubility the molten metal temperature increase. as the molten metal cools any dissolved hydrogen will come out of solution and forms small bubbles in t

11、he solidified metal called occlusions. 0n the rolling surface defects result.首先，氫被金屬吸收增加，其溶解性隨熔鑄金屬溫度升高而升高。熔鑄金屬冷卻時(shí)，氫會(huì)從溶液中揮發(fā)出來(lái)，在凝固的金屬上形成小氣泡被稱作吸留物，這種吸留物會(huì)影響軋制表面質(zhì)量，成為表面缺陷。l aluminum oxidel 氧化鋁secondly the presence of aluminum oxide which forms readily in oxygen and of course in air.第二，氧化鋁的存在，氧化鋁在氧氣中形成，當(dāng)然

12、在空氣中也形成。aluminum oxide can exist in any size particles called inclusions. considering that the thinnest foil rolled is about 0.2 thousandth of an inch (5.5 microns)and that the thickness of a drawn and ironed aluminum can wall is about this thickness then inclusion over about half this size are unac

13、ceptable.氧化鋁能夠以任何尺寸的顆粒存在，稱之為夾雜物?？紤]到最薄的軋制鋁箔的厚度大約是千分之0.2英寸（5.5微米）并且拉深鋁罐壁的厚度大約也是這個(gè)厚度，那么，如果夾雜物的厚度超過(guò)此尺寸的一半將不能被接受。(ii) metal filters金屬過(guò)濾器figure 1 shows the outline of the two most common aluminum filters used to remove hydrogen and assist in the extraction of aluminum oxide from the molten metal.圖1顯示了兩種最普

14、通的用于除去氫和幫助從金屬熔化物中除去氧化鋁的鋁過(guò)濾器的外形圖。l gas filtersl 氣體過(guò)濾器one is called a snif previously made by union carbide and the other an alpur made by pechiney (alcoa has a similar unit called a 622). these filter all operate on the same basis, that is passing sheared bubbles of argon gas with 2% to 3% of chlorin

15、e through the molten metal. this should extract any hydrogen to less than 0.2 milliliters (ccs) per 100 grams of metal (in fact to much less than this is standard) and lifts a high percentage of all aluminum oxide to the surface of the filters where it can be skimmed off.一個(gè)被稱之為snif，先前由union carbide制

16、造，另一個(gè)叫alpur,由pechiney生產(chǎn)（alcoa擁有類似裝置，叫做622）。所有這些過(guò)濾器操作基理相同： 將氬氣及濃度為2到3的氯的混合氣泡通過(guò)金屬熔化物。這將取出金屬中的氫，使之少于每100克0.2毫升（ccs）的氫（實(shí)際上甚至可以比這標(biāo)準(zhǔn)更少），及提升所有氧化鋁到過(guò)濾器的表層位置，然后可以撇去。l ceramic foam filtersin addition to the above type of filter most plants use a cff (ceramic foam filter) or a tkr (aluminum oxide or silicon car

17、bide) filter as a final filter. the first is a probability filter in the sense that it is self blinding while the second is a positive screen.陶瓷泡沫過(guò)濾器除了以上類型的過(guò)濾器，大多數(shù)工廠使用cff(陶瓷泡沫過(guò)濾器)或tkr（氧化鋁或碳化硅）型過(guò)濾器作為最終選擇。cff(陶瓷泡沫過(guò)濾器)是一種幾率性過(guò)濾器（因?yàn)樗旧硎且恍┟す埽?，而tkr（氧化鋁或碳化硅）是一種絕對(duì)的過(guò)濾器。the most common cffs are made by selee a

18、nd foseco while tkr filters which were first developed by keiser aluminum are widely used and marketed under that name in japan.最常見(jiàn)的cff過(guò)濾器由selee 和 foseco生產(chǎn)制造，而tkr過(guò)濾器最先由keiser鋁業(yè)公司研制，并在日本被廣泛使用和以此冠名銷售。the effectiveness of the above type of arrangement is that in the worlds biggest product which is can

19、body stock the occurrence of what is called split flanges during the body making process, has gone from 1 in 10,000 in 1980 to about ! in 1,000,000 as we speak.上述類型配置的效果是，對(duì)于世界上最大用量的罐體料產(chǎn)品中出現(xiàn)的問(wèn)題，被稱為罐體制造過(guò)程的開(kāi)裂問(wèn)題，像我們說(shuō)的那樣，已經(jīng)從1980年的1/10,000降到目前的1/1,000,000。a note of caution however is appropriate, and that

20、 is, that not all rolling plants have these facilities. in the absence of the above, surface quality can be adversely affected.但是，有一條注意事項(xiàng)：這就是，并不是所有的軋機(jī)工廠都有這些設(shè)備。沒(méi)有上述設(shè)備，表面質(zhì)量將受到不利影響。(iii) casting machines鑄造機(jī)v.d.c casters v.d.c鑄機(jī)figure no.2 depicts the type of machinery which is used for casting. the v.d

21、.c has had several developments over a period of years. the basic principle is to contain and cool the molten aluminum in a vertical drop (horizontal can be done but it is generally not favored). initially the molds were copper, then aluminum with rear water jackets and bottom mounted water sprays.

22、lubrication was and is done by pre-greasing the molds or injecting rape seed or castor oil over the contact surface.圖2描述了用于鑄造的機(jī)器類型。v.d.c鑄機(jī)在幾年中已經(jīng)經(jīng)歷了多次發(fā)展?；驹硎且粋€(gè)坩堝盛放和冷卻熔化鋁，垂直落下并凝固（水平方向能夠?qū)崿F(xiàn)但是一般不被采用）。最初結(jié)晶器為銅質(zhì)，然后是帶水套及底部裝有噴水器的鋁質(zhì)材料。由提前對(duì)結(jié)晶器加好油脂或?qū)佑|表面注入油菜仔或蓖麻油來(lái)實(shí)現(xiàn)潤(rùn)滑。the object is to freeze the peripheral alum

23、inum before it leaves the mold and to complete the solidification with the water sprays. to produce a good block surface the following parameters need attention:-目的是在脫離結(jié)晶器前將外圍鋁冷凍，使其在水噴射下完整凝固。形成良好鑄錠表面，需要注意以下參數(shù)：l quick solidification.快速凝固this of course is inhibited by the aluminum mold.這當(dāng)然是在鋁質(zhì)結(jié)晶器/模具內(nèi)完

24、成。l non binding of the contact surface接觸表面無(wú)粘滯lubrication, mold material and drop speed are factors.潤(rùn)滑，模型材料和下落速度是其影響因素。l safety water flow可靠的流動(dòng)水unsteady flow affects the rate of cooling and solidification. pressurization of the water head is usually done by a gravity tower for constancy and safety.不穩(wěn)

25、定的水流會(huì)影響冷卻及凝固速率。水位差增壓的持續(xù)性和可靠性通常由重力塔完成。l constant drop speed恒定的下落速度usually a hydraulic ram, single (better) or double acting is use. motor drives with wire hoist are used occasionally.通常液壓缸，使用單向（最好）或雙向執(zhí)行機(jī)構(gòu)。偶爾使用帶電纜提升的電機(jī)驅(qū)動(dòng)。failure to observe the above results in what is called blebs and cold shuts or ev

26、en a bleed out which means molten aluminum into the pit and the risk of an explosion. it is generally accepted that fast casting means a better surface finish and of course higher production. a good casting speed is just over 2 inches per minutes.如果不能遵守以上內(nèi)容，將導(dǎo)致叫做“水泡”現(xiàn)象和冷隔或甚至是漏鋁，這意味著熔化鋁流入鑄井，有爆炸的危險(xiǎn)。通常

27、認(rèn)為：快速鑄造會(huì)形成較好的表面光滑度（表面拋光），當(dāng)然也有較高的產(chǎn)量。好的鑄造速度恰恰超過(guò)每分鐘2英寸。l chill zone激冷區(qū)more importantly metal cast in this manner produces two zones near the surface of the cast block called a chill zone (on the outside) and a liquation zone ( inwards of this).最重要的是在這種方式下金屬鑄錠在接近鑄錠塊的表面形成兩個(gè)區(qū)域，一個(gè)為激冷區(qū)（外層），一個(gè)叫做熔析區(qū)（內(nèi)層）。the m

28、etal in these zones, particularly the very outside, where elements like magnesium，silicon and iron have come out of solution, due to slow cooing, is very hard and brittle and is particularly unsuitable for rolling, and if not removed by scalping will produce a quite unsatisfactory surface finish on

29、rolling. 這兩個(gè)區(qū)域的金屬，特別是區(qū)域最外層，在此區(qū)域，由于緩慢冷卻，如鎂，硅和鐵元素從溶液中析出，非常硬和脆，特別不適合進(jìn)行軋制，如果不銑削將其除去，在軋制時(shí)將會(huì)產(chǎn)生令人不滿意的表面光滑度。 two subsequent developments have seen the quality of cast block improve considerably. they are: -以下兩種發(fā)展極大的改善了鑄塊的質(zhì)量。這兩種發(fā)展是：l emc or electro magnetic castingemc或電磁鑄造this is where the molten is held sus

30、pended in a high frequency (1,000 kilo hertz) electro magnetic field and cooled by direct water sprays. there is of course no metal contact and cooling is as swift as can be achieved by direct spraying. this was invented by russian, getselev in about 1969 and while expensive is used widely in the us

31、a and europe but not in japan. 使熔化物懸浮在高頻率（1000千赫茲）的電磁場(chǎng)內(nèi)，由噴射水直接冷卻，當(dāng)然沒(méi)有金屬接觸，冷卻是由盡量快的直接噴射完成。這項(xiàng)技術(shù)由俄國(guó)人getselev大約在1969年發(fā)明，并在美國(guó)和歐洲被廣泛使用，不包括日本。l lhc or low head carbonlhc或低液面石墨復(fù)合材料結(jié)晶器in this method the metal is contained by a porous carbon band through which oil and nitrogen are passed. there is little or n

32、o metal contact and cooling is done by direct water sprays. this development was carried out by wagstaff and has been available for about 2 years. in both the above methods the combined chill and liquation zones are very small. with emc the zone depth is negligible and with lhc perhaps a few thousan

33、dths of an inch.在這種方法中，金屬被包含在油和氮可通過(guò)的多孔可滲透碳夾層中。有很少或沒(méi)有金屬接觸，由噴射水直接冷卻。這種技術(shù)由wagstaff研發(fā)，已經(jīng)應(yīng)用了兩年。在以上兩種方法中，激冷和偏析區(qū)非常狹小。在emc中兩種區(qū)域深度可以忽略，在lhc中或許有千分之幾英寸的區(qū)域。(4) continuous casters連續(xù)鑄造機(jī)there a three recognized form of continuous caster. they are the roll caster, the hazelett steel belt caster and the alluisse/ la

34、uener block caster. 有三種公認(rèn)的連續(xù)鑄造機(jī)形式，分別是輥式連鑄機(jī)，hazelett鋼帶連鑄機(jī)和alluisse/ lauene塊式連鑄機(jī)figure no.3 shows these casters.圖3給出了這些連鑄機(jī)。roll caster輥式連鑄機(jī)the roll caster normally has 2 cast iron water cooled work rolls reducing hot metal to a strip about a 1/4 inch thick. two common manufacturers are hunter and pech

35、ineyo. the cast strip passes through a 2 or 4 high hot reduction mill which can reduce the strip to about 1/8” or 2 meters with an annual output of 50 million pounds. usual alloy are 1xxx, 3xxx, and 5005. no 3004 or 5182 is rolled and very little 5052.輥式連鑄機(jī)通常有2個(gè)水冷鑄鐵工作輥，將熱金屬軋制為1/4英寸厚的板材。兩個(gè)常見(jiàn)制造商為hunte

36、r公司pechineyo公司。板材鑄件通過(guò)2或4輥熱板材軋機(jī)， 使板材軋成1/8”或兩米，年產(chǎn)量50000萬(wàn)磅重。通常合金種類為1xxx系列，3xxx系列和5005。沒(méi)有3004或5182被軋制，有很少的5052采用這種方式。the only application for hot mill coolant is in the hot reduction mill. quaker has been active in this field. 熱軋冷卻液只用于熱板材軋機(jī)，quaker在這一領(lǐng)域非?；钴S。l hazelett casterthe hazelett caster uses steel

37、 belt to form a 3/4” thick sheet which then passes through a 4 high hot reduction mill reducing the sheet to about a 1/4” thick for coiling or cold reduction. sheet profile is a problem. can sheet is not viable product. again there is an application for hot mill coolant. hazelett連軋機(jī)使用鋼帶來(lái)冷卻鑄造3/4”厚的板材

38、，然后通過(guò)4連軋軋機(jī)軋制成成卷或冷軋1/4”厚的材。卷材凸度是一個(gè)問(wèn)題，罐料板材產(chǎn)品不能采用這種方式，熱軋冷卻液再一次被應(yīng)用。l aluisse/lauener casterthe aluisse/lauener caster uses nickel plated copper blocks to form a sheet about 3/4”thick. a 4 high hot reduction mill follows reducing the sheet to about 1/4”. surface quality may be a problem and maintenance i

39、s high. again there is an application for hot mill coolant.aluisse/lauene連鑄機(jī)使用鍍鎳的銅塊來(lái)冷卻鑄造3/4”厚的板材，之后經(jīng)過(guò)4輥熱連軋將板材軋制1/4”厚。表面質(zhì)量可能是一個(gè)問(wèn)題并且維護(hù)費(fèi)用高，熱軋冷卻液再一次被應(yīng)用。there are only 2 such caster in existence. a 32” wide caster at golden and a 64” at san antonio where an attempt was made to make can body stock from 50

40、17. can end stock was tried on both casters but only small width 5182 seems to have succeeded at golden.只有兩種類型的連軋機(jī)存在，一個(gè)是golden的32”寬的連軋機(jī)，另一個(gè)是san antonio的64”寬的連軋機(jī)。試圖使其能夠使5017變成罐體材料，兩種類型連鑄機(jī)都嘗試過(guò)生產(chǎn)罐蓋材料，但是只有小寬度的5182帶材在golden試軋取得成功。both the above types of casters seemingly have large capacities up to 200 m

41、illion pounds per annum and of course could produce some aluminum feed at very low cost. 以上兩種類型的連鑄造具有每年高達(dá)200000萬(wàn)磅的產(chǎn)能，當(dāng)然也可以在非常的低成本下生產(chǎn)某些鋁料。l thin-strip castersl 薄帶鑄機(jī)these casters producing strip at about 1/10 thick at five times the normal speed have been recently developed. a davy model at granges sw

42、eden produces foil stock. it remains to be seen whether there will be a challenge to can stock. 這種能夠以一般速度的5倍生產(chǎn)約1/10厚的卷材薄帶鑄機(jī)已經(jīng)被研發(fā)出來(lái)。在瑞典granges，一種為davy型的連鑄機(jī)能夠生產(chǎn)鋁箔坯料，是否能夠生產(chǎn)罐坯料將會(huì)是一個(gè)挑戰(zhàn)。l metallurgyl 冶金a peculiar attribute of continuous cast aluminum is its ability to work harden at about twice the rate o

43、f v.d.c. cast metal. while not a problem with soft alloys or those with a high aluminum content，it is however disadvantageous with alloys causing a need for additional annealing during rolling. 連續(xù)鑄鋁的一個(gè)特性是能夠在v.d.c.鑄造機(jī)鑄造金屬兩倍率速度下變硬，對(duì)軟合金或鋁含量高的合金不成問(wèn)題，但弱點(diǎn)是合金在軋制過(guò)程中需要退火處理。l foil stockl 鋁箔坯料in usa nearly all

44、 foil stock is made with roll caster. the alloy is chiefly 1xxx. the surface course is not scalped and some oxide may persist. minimum finished foil gauge rarely falls below 6.5 microns whereas japanese and european foil mills roll block for foil down to 5.5 microns. this situation is probably more

45、forgiving for the usa product and of course there is a significant cost saving.在美國(guó)幾乎所有的鋁箔坯料都由輥式連鑄機(jī)制造，合金主要是1xxx系列。表面未經(jīng)銑削,可能存在許多氧化物。最小的成品鋁箔厚度很少在6.5微米以下，但日本和歐洲的鋁箔軋機(jī)生產(chǎn)的鋁箔達(dá)到5.5微米，這種情況對(duì)美國(guó)產(chǎn)品可能更加寬松，節(jié)省了大量成本。3. scalping銑削(i) surface表面not only is the depth of the chill and liquidation zones affected by the nat

46、ure of the casting process, but there is also a variation caused by alloy content. with normal v.c.d. casting （i.e. not emc or lhc）there is a need to remove 3/8” of the surface of lxxx series alloys and l/2” or more for all others. figure no 4 shows a diagrammatic representation of double sided hori

47、zontal and vertical surface scalping.不僅是激冷和偏析區(qū)域的深度受鑄造過(guò)程/工藝的影響，也有合金成分引起的變化。正常v.c.d.鑄造（也就是非emc或lhc）鑄錠，需要除去1xxx系列合金3/8”的表面，其他系列合金出去l/2”或更多的表面。圖4說(shuō)明了水平和垂直雙側(cè)的銑削。the only other concern arising with vdc casting is the question of geometric linearity or block squareness. if this is not within reasonable limi

48、ts then additional scalping may be called for.唯一與其他vdc鑄造所引起的關(guān)注問(wèn)題是幾何線性或鑄塊垂直度，如果沒(méi)有控制在合理的范圍內(nèi)，那么就需要額外的銑削。in earlier days some emc block was rolled un-scalped but surface oxidization and bruisingduring handling has generally seen the cessation of this practice.在早期，許多emc塊料未經(jīng)銑削就進(jìn)行軋制，但在軋制過(guò)程中表面存在氧化和硬傷，表面質(zhì)量受到

49、影響，因此這種處理方法已經(jīng)停止。emc and lhc cast block will normally need a minimum of 1/4 of surface metal removed. this minimum is mechanically dictated not metallurgical.emc和lhc鑄塊通常情況下至少去除1/4的金屬表面，這一最小量是機(jī)械規(guī)定而非冶金要求。the presence of chill or liquation zone metal in the surface of the block will produce a very indif

50、ferent surface during the rolling process.存在于鑄塊表面激冷和熔析區(qū)的金屬，在軋制過(guò)程中將會(huì)產(chǎn)生中性表面。it is quite possible to produce a mirror finish on the rolling block with the milling knives of a scalper. a finish in fact much smoother than can be achieved by rolling. because of the propensity to cause skidding on the firs

51、t hot mill pass the scalped finish on any rolling block is considered to be better if it dose have minor patterned striations rather than mirror finish.用銑刀在軋制塊上銑削，可達(dá)到鏡面的光潔度，銑削后的光潔度比軋制達(dá)到的光潔度高。因?yàn)槿魏我粋€(gè)銑削后的鑄塊熱軋第一軋制道次軋制時(shí)有引起測(cè)滑/滑動(dòng)的傾向，如果軋制塊有輕微圖案條紋而不是鏡面光潔度，那么認(rèn)為是比較好的。(ii)edge 邊the question of the need to scalp

52、 is rather a different issue. traditionally rolling blocks have not been edge scalped. hard alloy such as 5182 can produce very brittle edges and the presence of small quantities of sodium calcium or even lead may cause brittleness in other alloys.銑削問(wèn)題是一重要問(wèn)題，傳統(tǒng)軋制坯料從不進(jìn)行邊緣銑削。硬合金如5182能夠產(chǎn)生非常脆的邊緣，少量的鈉鈣或鉛

53、可導(dǎo)致其他合金的脆性。during rolling on the hotline a sheet of alloys tends to crack and the slivers so generated migrate to the bottom of the sheet via the hot line table rolls. these slivers will pass through the hot finishing mill and cold mills and in doing so transfer themselves to both sides of the sheet

54、 during coiling, and subsequently affect the surface finish. can-makers particularly dislike slivers.在熱軋軋制過(guò)程中鋁板產(chǎn)生裂紋，碎裂的細(xì)片通過(guò)熱軋輥道移動(dòng)到鋁板材的底部，這些碎料經(jīng)過(guò)熱精軋機(jī)和冷軋機(jī)，在卷取過(guò)程中轉(zhuǎn)移到板帶的兩側(cè)，隨后影響到表面光潔度，制罐商特別討厭裂片。slivers can be avoided by edge scalping，using emc or lhc cast block and to a lesser extent by individually spray

55、ing the hot line table rolls with coolant from a system totally separate from the hot reversing or finishing mills to avoid particle and bacteria contamination通過(guò)邊部銑削可以避免裂片，使用emc或lhc鑄塊和在較小程度上通過(guò)從可逆式熱軋或精軋的一個(gè)系統(tǒng)完全獨(dú)立采用冷卻液?jiǎn)为?dú)噴射熱軋輥道可避免顆粒和細(xì)菌污染。the presence of slivers can now be easily detected in the finishin

56、g area during surface inspection by laser or ccd units.碎片在精軋區(qū)域通過(guò)激光或ccd裝置很容易被探測(cè)到。(iii) head and tails頭和尾 many rolling mills cut or crop either one or both ends of every rolling block. the reason is to prevent the bruising of the hot mill work roll on the first pass and reduce the scatter of any slive

57、rs from the head or tail of the block. (bearing in mind all this metal is chilled or liquated.) the situation is of course exacerbated more with alloyed metal rather than pure.許多軋廠把每個(gè)軋塊的一端或兩端切斷或剪掉，原因是防止熱軋工作輥首道次軋制時(shí)產(chǎn)生擦劃傷以及減少裂片從頭端或尾端的擴(kuò)散。（所有金屬經(jīng)過(guò)激冷和熔析）。合金金屬產(chǎn)生的擦劃傷或裂片從頭端或尾端的擴(kuò)散程度比純金屬嚴(yán)重。in any event it is always desirable to take a 75 reduction(compared to whatever the standard is) on t