外文翻譯--平行矯正輥的數(shù)量對(duì)矯正過程的影響

1、<p><b>　　原文</b></p><p>　　The Effect of the Number of Leveling Rolls on the Straightening Process</p><p>　　Curvature Analysis</p><p>　　The output of the strain model

2、 can be used to formulate a fundamental understanding of the leveling process .A series of simulations was run for 3/8-inch-gauge material with a yield strength of 50 ksi. The simulations were performed for an 11-roll l

3、eveler with five top rolls and six bottom rolls, which has 6-inch-diameter rolls spaced on 10-inch center.</p><p>　　Two parameters were varied during the study: the extent of plastic deformation and the magn

4、itude of the initial flatness defects. The model was run for levels of plastic deformation ranging from 20% to more than 90% of the material’s cross-section. For example, a fraction plastically deformed of 0.50 represent

5、s a bend that creates yielding in 50% of the cross-section—the outermost 25% at the top and bottom surfaces. The include stresses in the innermost 50% of the cross-section never exceed the </p><p>　　For each

6、 level of plastification, the model tracks the strain history for each initial condition through every bend in the leveler, and predicts the exiting flatness condition. The exiting flatness condition represents the predi

7、cted deviation of the plate from a horizontal flat surface over a 12-foot length, as prescribed in the ASTM A6 standard for plate. The output of the study is shown in Figures 10~13.</p><p>　　Figure 10 shows

8、the manner in which the predicted curvature varies as the extent of plastic deformation changes for material with an initial radius of curvature of 15 inches. This curvature represents the condition of the inside wrap of

9、 a coil with a 30-inch inside diameter. Three initial longitudinal flatness condition are simulated: an initial positive radius of curvature of 15 inches (bowed up); an initial negative radius of curvature of 15 inch (bo

10、wed down); and an initially flat region. Thr</p><p><b>　　Figure 10</b></p><p>　　The model predictions displayed in Figure 10 show that, at low levels of plastic deformation, the thre

11、e initial conditions result in three distinctly different exiting conditions. The magnitudes of the initial flatness defects are reduced, but they are still large. The initially bowed-up defect exits the leveler with an

12、upward bow of approximately 5.5 inches over a 12-foot length, even when the roll gap of the leveler is set to generate a plastic fraction of only 0.20.The initially bowed-down de</p><p>　　As the extent of pl

13、astic deformation increases, the predicted exiting flatness defects decrease in magnitude, and the exiting conditions for the three different initial curvatures eventually converge to the same value at a fraction plastic

14、 deformation of 0.62.The point beyond which the curves the different incoming conditions identically coincide is termed the convergence point.</p><p>　　The exiting flatness condition displays an oscillatory

15、with plastification rates greater than 50%.The predicted exiting condition is a bow up for plastification rates below 53%.The exiting flatness condition is perfectly flat at a fraction plastic of 0.53, with entry roll ga

16、p of the leveler is set to generate plastification rates between 53% and 64%, the predicted exiting flatness condition is a bow down. The maximum predicted bow in 12 feet is 5/8 inch, and occurs at a fraction plastic of

17、0.58.</p><p>　　The existence of several “zero points” is an underlying reason why successful leveling is achieved in practice, and explains why experienced operators may use very different settings and yet s

18、till obtain the same leveling effect for a particular combination of thickness and yield strength.</p><p>　　Figure 11 shows the variation in the predicted exiting flatness condition for the same material whe

19、n the incoming flatness condition has an initial radius of curvature of 50 inches. This condition represents the outer wraps of a large coil having an outside diameter of 100 inches. The three incoming conditions simulat

20、ed are an initial positive radius of curvature of 50 inches(bowed up),an initial negative radius of curvature of 50 inches(bowed down),and the initially flat control condition. The </p><p><b>　　Figure

21、11</b></p><p>　　Figure 12 displays the predicted exiting flatness condition for a discrete plate, rather than a coiled product, of the same material processed on the same leveler. The incoming radius o

22、f curvature is 1000 inches, which simulates an initial bow up of 2.60 inches in 12 feet, a bow down of 2.60 inches and an initially flat region. This range of flatness defect is typical of a heat treated plate. The model

23、ed results are generally similar to those for the coiled condition simulations. However, severa</p><p><b>　　Figure 12</b></p><p>　　The magnitude of the exiting flatness prediction is

24、 markedly smaller at very low levels of plastic deformation and is positive (bowed up) for all incoming conditions. The initial 2.60-inch bowed-up defect is reduced to 1.74 inches, and the initially bowed-down defect exi

25、ts as a 0.28-inch upward bow, even when only 20% of the plate’s cross-section is plastically deformed. The positive curvature applied during the first bend reverses the incoming curvature from bowed down to bowed up.<

26、/p><p>　　The variation in the predicted exiting flatness condition is significantly reduced for the less severe initial condition. The range of exiting out-of-flat conditions for the plate at a fraction plastic

27、ally deformed of 0.20 is from 0.28 to 1.74 inches, compared to range of -3.60 to 5.46 inches for the inside wrap of a coil processed at the same leveler settings.</p><p>　　The predicted exiting flatness valu

28、e is less than 0.50 inch in magnitude for plastification rates between 36% and 54%.</p><p>　　The convergence point also occurs at significantly reduced levels of plastic deformation for the plate simulation

29、(0.48) compared to the coiled product (0.62), and the oscillatory behavior begins earlier, at a fraction plastically deformed of 0.40.</p><p>　　The predicted behavior is identical to the simulated coiled con

30、ditions for all plastification rates greater than 62%, and crossover points occur at the same locations (0.53, 0.64, 0.75, 0.85 and 0.94).</p><p>　　Figure 13 shows the variation in the predicted exiting flat

31、ness condition for 3/8-inch-gauge discrete plate when the incoming flatness condition has an initial radius of curvature of 2000 inches. This condition simulates even smaller incoming defects, including an initial bow up

32、 of 1.30 inches, a bow down of 1.30 inches and an initially flat region. The magnitude of these flatness defects is typical of the distortion seen in an as-rolled and air-cooled distortions plate. The predicted exiting f

33、l</p><p><b>　　Figure 13</b></p><p>　　The convergence point is reduced even further (0.46), and the variation between exiting values never exceeds 0.75 inch for the various incoming c

34、onditions. The divergent tails of the left end of the curve, which were more than 9 inches apart in Figure 10, are converging to a single line as the incoming flatness defect is reduced. The initially bowed-down conditio

35、n decreased in magnitude, became positive, and is now approaching the same value with which the initially flat condition exits the leve</p><p>　　Figures 10-13 show that the predicted exiting flatness can var

36、y significantly below the convergence point. In this region, the severity of the incoming flatness condition has significant influence on the magnitude of the exiting condition. The applied plastic deformation is not suf

37、ficient to correct the incoming condition. The predicted flatness above the convergence point is identical for all incoming flatness condition, regardless of their magnitude. The applied curvature exceeds the incoming &l

38、t;/p><p>　　The results predicted by the model for an 11-roll leveler have been verified by field trials. They have also been verified for both tilting cassette levelers and machines with independent roll adjust

39、ment. The model predicts similar results for both different gauges and different yield strengths.</p><p>　　The Effect of Additional Leveler Rolls</p><p>　　The oscillatory behavior displayed in F

40、igures 10-13 can be explained by examining the influence of the individual leveling rolls on the straightening process. Figure 14 shows a schematic of the leveler rolls superimposed on the predicted flatness curve for an

41、 incoming flatness defect with an initial radius of curvature of 2000 inches(see Figure 13).The first three-roll triplet, which includes the first top roll of the leveler, controls the exiting flatness for low levels of

42、plastic deformation, </p><p><b>　　Figure 14</b></p><p>　　The third triplet, consisting of the second top roll and the second and third bottom rolls, controls the exiting flatness whe

43、n the deformation levels are in the range of 0.38-0.48.The upward curvature imparted to the plate by this bend increase the magnitude of the exiting upward bow.</p><p>　　Setting the entry roll gap to increas

44、e the applies deformation to levels above 0.48engages the next downward bend. This bend reduces the magnitude of the exiting upward bow until, at a fraction plastically deformed of 0.53,the plate exits the leveler with p

45、erfect flatness. Higher levels of plastic deformation cause the plate to exit with a downward bow of increasing magnitude, until a level of 0.58, corresponding to a downward bow of 0.625 inch. At this point, the next top

46、 roll, by is applicatio</p><p>　　The fourth bottom roll, by its application of negative bending curvature, reduces the magnitude of the upward bow, and a third crossover point occurs at a fraction plasticall

47、y deformed of 0.75.The influence of this roll continues until 2.25 inches, corresponding to a deformation level of 0.80.The fourth top roll controls the exiting curvature from this point, until a fraction plastically def

48、ormed level of 0.90,and introduces a fourth crossover point at 0.85.Beyond a plastification of a negative </p><p>　　Additional simulations were performed for levelers with a greater number of leveling rolls.

49、 The same three incoming flatness conditions were simulated for the same gauge(3/8 inch)and the same yield strength(50 ksi)processed on levelers with identical roll diameters(6 inches)and roll spacing(10 inches).The addi

50、tional simulations were performed on levelers with 13,15,17 and 19 rolls. The results for the two extreme conditions-the inside wrap of a coil(15-inch initial radius of curvature)and an as-</p><p>　　Several

51、observations can be made from these simulations and are summarized in Table 1.As the number of leveling rolls increases, the following occurs:</p><p>　　The divergence of the left-hand tails of the curves is

52、decreased. The predicted exiting flatness defects are slightly reduced at low levels of plastic deformation.</p><p>　　The oscillatory behavior does not begin until higher levels of plastic deformation. The m

53、agnitudes of the peaks remain identical, but occur at greater deformation levels. They appear to move to the right of the graphs. For example, the location of the upward bow peak of magnitude 1.2 inches is listed in Tabl

54、e 1. For the 15-inch initial radius of curvature, it moves from a fraction plastically deformed value of 0.70 for the 11-roll leveler to 0.80 for the 15-roll leveler to 0.86 for the 19-roll m</p><p>　　The co

55、nvergence point for the three different incoming flatness curves occurs at lower levels of plastic deformation. Convergence occurs for the 15-inch initial radius of curvature at a fraction plastically deformed value of 0

56、.62 for the 11-roll leveler, at 0.52 for the 15-roll leveler, and at 0.50 for the 19-roll machine.</p><p>　　The” sweet spot”-the area of relative insensitivity to plastic deformation, or leveler gap settings

57、-is widened. The range for the 11-roll leveler for an incoming radius of curvature of 15 inches is only from a fraction plastically deformed value of 0.50-0.56.It increases to a range of 0.40-0.70 for the 15-roll machine

58、 and to 0.38-0.78 for the 19-roll leveler.</p><p><b>　　Table 1</b></p><p>　　The number of crossover points, or roll gap settings that produce perfect flatness, increases. The number

59、of crossover points equals the number of top leveler rolls. There are five crossover points for the 11-roll leveler, seven for the 15-roll leveler and nine for the 19-roll machine.</p><p><b>　　Summary&

60、lt;/b></p><p>　　A roller leveler straightens material by bending it in both directions via leveler rolls acting together in groups of three.</p><p>　　Each additional pair of leveler rolls add

61、s the capability for one additional bend in each direction.</p><p>　　The function of take all incoming flatness conditions on the plate, regardless of their direction, and bend them to a bow, or curvature, t

62、hat is in the same direction. Upon exiting the first bend, all areas have been transformed to one outgoing flatness condition with different magnitudes of severity.</p><p>　　The second bend applies a bending

63、 action in the opposite direction. Upon exiting the second bend, all incoming flatness defects are uniformly bent to the same curvature.</p><p>　　The remaining rolls in the leveler are designed to gradually

64、remove the plate curvature induced by the leveler and deliver a flat product.</p><p>　　At low levels of plastic deformation, the incoming flatness defects may be reduced, but they are not eliminated. As the

65、extent of plastic deformation increases, the predicted exiting flatness defects decrease in magnitude, and the exiting conditions for the three different possible initial curvatures eventually converge to the same value.

66、 The point beyond which the curves for the different incoming conditions identically coincide is termed the convergence point.</p><p>　　The exiting flatness condition displays an oscillatory behavior with pl

67、astfication rates greater than the convergence points. This behavior can be explained by the influence of each additional bend in the leveler. As the extent of plastic deformation increases, more leveler rolls apply bend

68、ing curvature that is sufficient to reduce the magnitude of the flatness condition or to change its direction.</p><p>　　The addition of more leveler rolls results in convergence of the various different inco

69、ming flatness conditions at lower levels of plastic deformation.</p><p>　　The addition of more leveler rolls delays the start of the oscillatory behavior until higher levels of plastic deformation, thus incr

70、easing the ”sweet spot” of the leveler, or the range of operation where the exiting flatness is relatively insensitive to the roll gap settings.</p><p>　　The addition of more leveler rolls increases the numb

71、er of crossover points, where the predicted exiting flatness is zero. More crossover points allow more opportunities to produce perfect flatness. The number of crossover points equals the number of top leveler rolls.<

72、/p><p>　　Additional rolls increase the total force that the leveler must handle, as well as the total horsepower required to drive the plate through the machine. Selecting the proper number of rolls for a level

73、er is a compromise between the desired ease of leveling, the required exiting flatness, and the size and cost of the machine.</p><p>　　The simulation results presented here are for 3/8 –inch-gauge material w

74、ith a yield strength of 50 kis. The model predicts similar results for both different gauges and different yield strengths.</p><p>　　The results predicted by the model for an 11-roll leveler have been verifi

75、ed by field trials. They have also been verified for both tilting cassette levelers and machines with independent roll adjustment.</p><p><b>　　譯文</b></p><p>　　平行矯正輥的數(shù)量對(duì)矯正過程的影響</p&

76、gt;<p><b>　　曲率分析</b></p><p>　　一個(gè)基本的矯正過程可用一個(gè)輸出變量應(yīng)變函數(shù)來表示。將厚度為3/8英寸的鋼板在50ksi屈服強(qiáng)度下進(jìn)行一系列矯正。此矯正機(jī)為上5輥下6輥的11輥矯正機(jī)，矯正輥輥徑為6英寸，中心距為10英寸相互交叉排列。</p><p>　　兩個(gè)不同參數(shù)的研究：塑性變形程度和矯前鋼板平面缺陷的嚴(yán)重程度。從該函數(shù)

77、可以看出原來橫截面積的20%到90%發(fā)生了塑性變形。例如，曲率為1/2的微小塑性變形就能矯正出50%的橫截面積，其中上下兩表面各為25%，而鋼板內(nèi)部50%未達(dá)到屈服應(yīng)力。</p><p>　　每一個(gè)階段的塑性變形，經(jīng)過一個(gè)彎輥，該函數(shù)就能表示出每個(gè)初始條件和最終矯正后的表面質(zhì)量。矯正后在平整條件下測(cè)出的鋼板橫向厚差為12英寸，達(dá)到了美國的ASTM標(biāo)準(zhǔn)板A6。研究的結(jié)果如圖10-13所示。</p>&

78、lt;p>　　如圖10所示，原始曲率半徑為15英寸的鋼板隨塑性變形程度的變化而殘余曲率半徑也有所變化。這個(gè)曲率相當(dāng)于卷曲一個(gè)內(nèi)徑為30英寸的鋼板。三個(gè)縱向平整條件進(jìn)行模擬：一個(gè)原始曲率半徑為正15英寸上彎的鋼板，一個(gè)原始曲率半徑為負(fù)15英寸 的下彎鋼板和一個(gè)平直的鋼板。研究三個(gè)不同初始條件的鋼板對(duì)矯正鋼板的影響。 對(duì)彎曲過程進(jìn)行分析，原始平直鋼板作為比較。然而，這對(duì)不連續(xù)矯正鋼板的分析是有用的，因?yàn)樵计矫嫒毕莞鱾€(gè)區(qū)域是不同的，還

79、有不連續(xù)鋼板原來大體上是平直的。</p><p>　　這個(gè)實(shí)驗(yàn)結(jié)果在圖10中可以看出，在較低的塑性變形條件下，這三個(gè)條件導(dǎo)致了不同的矯正效果。雖然原始平面缺陷少，但它們的差距較大。最初彎曲鋼板在12英尺長，曲率半徑為5.5英寸的矯正輥上矯正，即原始向下彎曲與同一方向的彎曲曲率下進(jìn)行矯正，矯正的輥縫也只能使其產(chǎn)生1/5的塑性變形，其嚴(yán)重的缺陷將減少到3.60英寸。原始平面向上彎曲接近1英寸的鋼板矯正，反映了在第一彎

80、輥上的正向彎曲曲率。較小的塑性變形反彈后還保留一定的殘余彎曲變形。其它彎輥矯正中不用較大的塑性變形，以減少大的彎曲曲率。</p><p><b>　　圖 10</b></p><p>　　由于塑性變形程度的增加，原平面缺陷進(jìn)一步減少，矯正后三個(gè)不同條件的原始曲率最終得到相同的微小塑性變形，其值為0.62。這三個(gè)不同條件下的這一點(diǎn)稱為重合點(diǎn)。</p>&l

81、t;p>　　這個(gè)平穩(wěn)的矯正情況顯示在塑性變形程度大于50%上波動(dòng)。預(yù)計(jì)矯正后塑性變形程度低于53%。平面矯正為 0.53的微小塑性變形，進(jìn)入輥縫矯正后將產(chǎn)生53%至64%之間的塑性變形，顯示鋼板矯正向下彎曲，最高彎曲在12英尺處，其值為5/8英寸，發(fā)生了0.58的塑性變形。鋼板再次經(jīng)過輥縫矯正，塑性變形程度為0.64，塑性變形在0.64至0.75之間將產(chǎn)生向上彎曲。塑性變形在0.70處有最大彎曲值，為12英寸。第三個(gè)重合點(diǎn)發(fā)生在0

82、.75位置，再次得到完全平直。塑性變形在75%和85%之間發(fā)生向下彎曲，變相程度在80%時(shí)有最低值，為2.5英寸。第四個(gè)重合點(diǎn)發(fā)生在變形程度為0.85處，進(jìn)入輥縫后塑性變形程度在85%至94%之間發(fā)生向上彎曲。最高值發(fā)生在變形程度為0.90處，其值為6.1英寸。 最后重合點(diǎn)發(fā)生在0.94處，之后，隨著塑性變形程度的增大，負(fù)曲率也不斷變大。例如，輥縫值設(shè)置為使塑

83、性變形程度為96%時(shí)將產(chǎn)生6.2英寸的向下彎曲。</p><p>　　存在不同的“零點(diǎn)”的根據(jù)是在實(shí)踐中成功的技術(shù)水平下取得的，同時(shí)解釋了為什么經(jīng)驗(yàn)豐富的技術(shù)員用完全不同的參數(shù)值，同樣可以獲得平直效果和厚度尺寸以及屈服強(qiáng)度要求。</p><p>　　圖11顯示的是相同材料的平面情況下，矯正前平板的原始曲率半徑為50英寸。這個(gè)情況相當(dāng)于卷曲一個(gè)有著100英寸外徑的鋼板。三個(gè)矯正前情況模擬，一

84、個(gè)曲率半徑為正50英寸上彎，一個(gè)曲率半徑為負(fù)50英寸下彎，和一個(gè)平直鋼板。這個(gè)結(jié)果和圖10顯示原始曲率為15英寸時(shí)的完全一樣。在較低的塑性變形情況下，彎曲后不能被矯正。顯示矯正后缺陷和最初平面區(qū)域是相同的（不變條件）因?yàn)橄嗤淖冃芜m用于相同的初始情況。矯正前曲率半徑為正50英寸和負(fù)50英寸與校正前曲率半徑為15英寸相比顯示矯正后結(jié)果要小，反映了不太嚴(yán)重的平整度缺陷。相同數(shù)值的平整度修正適用于較小區(qū)域的缺陷。作為三個(gè)矯正板，該顯示值下降幅

85、度最終重合于塑性變形程度為0.62的點(diǎn)（重合點(diǎn)）。顯示的事實(shí)結(jié)果對(duì)于塑性變形程度大于62%的矯正都是相同的。重合點(diǎn)依次出現(xiàn)在塑性變形程度為0.53、0.64、0.75、0.85和0.94處。</p><p><b>　　圖11</b></p><p>　　圖12顯示的是顯示相同材料和矯正輥矯正后平面情況的不連續(xù)矯正鋼板，而不是一個(gè)連續(xù)的鋼板。即將矯正曲率半徑為1000

86、英寸，12英尺長的原始彎曲曲率半徑為2.60英寸，一個(gè)向下彎曲為2.60英寸和一個(gè)平直的鋼板。 這一系列的平整度缺陷可以看出其是典型的熱處理板。該模擬結(jié)果大致類似卷曲狀態(tài)模擬。然而，一些重大區(qū)別可以看出是離散還是連續(xù)模擬：</p><p>　　大的平面表明較小的塑性變形對(duì)所有的矯正前情況都是正的（向上彎曲）。原始曲率為2.60英尺向上彎曲缺陷減小到1.74英寸，和原始向下彎曲缺陷矯正后向上彎曲為0.28英寸，即使

87、只有橫截面積20%塑性彎曲變形。正曲率適用于第一彎輥，曲率從向下彎曲變成向上彎曲。</p><p><b>　　圖 12</b></p><p>　　那么對(duì)于嚴(yán)重平面缺陷得鋼板對(duì)矯正后鋼板的平面缺陷就大大減小了。相比較為-0.36至5.46英寸范圍內(nèi)的同一矯正設(shè)備，塑性變形程度為0.20的鋼板矯正后曲率半徑0.28到1.74英寸。</p><p&g

88、t;　　顯示塑性變形程度在36%到54%之間矯正后平整度值小于0.54英寸。與彎曲鋼板（0.62）相比，重合點(diǎn)也會(huì)出現(xiàn)在塑性變形程度（0.48）顯著減少的鋼板上，在微小的塑性變形值為0.40，其之前就發(fā)生了波動(dòng)。</p><p>　　顯示所有塑性變形程度大于62%的連續(xù)矯正鋼板的效果是相同的，重合點(diǎn)發(fā)生在同一位置（0.53、0.64、0.75、0.85和0.94）。</p><p>　　圖

89、13顯示的是矯正后平整度為3/8英寸規(guī)格的不連續(xù)鋼板的變化，矯正前的原始曲率半徑為2000英寸。 這種情況甚至是更小的矯正缺陷，其中包括矯正前向上彎曲曲率半徑為1.30英寸，向下彎曲曲率半斤為1.30英寸和平直的鋼板。這些典型的干板缺陷是由于冷軋和空冷扭曲產(chǎn)生的。顯示塑性變形程度低的情況下平整度是非常小的，都向上彎曲，和三個(gè)不同條件下的變化差別不大。因?yàn)椴捎昧怂苄宰冃吻?，最初塑性變形程度?0%的1.30英寸的向上彎曲缺陷增加到1.3

90、7英寸，但是這個(gè)值比類似于曲率半徑為1000英寸的缺陷較?。?.74英寸）。矯正前向下彎曲0.62英寸的缺陷，比原始曲率為1000英寸的半徑（0.28英寸），與其它原始條件的效果是最接近的。</p><p>　　重合點(diǎn)的值進(jìn)一步降低（0.46），和矯正后的各種條件下的效果差異不會(huì)超過0.75英寸。除了在圖10那種情況以外，其它圖的曲線都在大于9英寸后分叉重合為平整缺陷減小的單一曲線。最初向下彎曲下降的幅度是正的，

91、現(xiàn)在與最初矯正后矯正（0.99英寸）的效果已經(jīng)趨于相同。最初向上彎曲幅度有所下降的情況作為新的曲率半徑同樣較少，也與最初平直狀態(tài)的效果的相同。顯示的情況與前面所有塑性變形程度大于0.62的例子是相同的，有著同樣的五個(gè)重合點(diǎn)。然而，由于較大的原始曲率半徑減小，曲線在0.62以下趨于平坦，矯正后的塑性變形程度為38%時(shí)接近零（初始向上彎曲，平直和向下彎曲分別為0.26、0.22和0.19英寸）。</p><p>&l

92、t;b>　　圖13</b></p><p>　　圖10-13顯示矯正后的平面大大低于重合點(diǎn)。在這方面，較大的矯正前平面條件在矯正后有比較大的影響。對(duì)正確的矯正塑性變形的應(yīng)用是不夠的。對(duì)所有的矯正前平整條件上述平面的重合點(diǎn)都是相同的。矯正后的曲率超過矯正前的曲率。矯正后的曲率視彎輥的矯正決定而不是由嚴(yán)重的原始平面缺陷決定的。</p><p>　　顯示結(jié)果表明11輥矯正機(jī)已通

93、過現(xiàn)場的實(shí)驗(yàn)驗(yàn)證。他們還證實(shí)了傾斜輥和單獨(dú)調(diào)整矯正輥的設(shè)備。該矯正機(jī)顯示，利用不同的壓力和不同屈服強(qiáng)度結(jié)果都是類似的。</p><p><b>　　變輥距的影響</b></p><p>　　在圖10-13顯示的波動(dòng)可以解釋為檢驗(yàn)對(duì)各別矯正過程的影響。圖14顯示矯正輥疊加和原始曲率半徑為2000英寸平坦曲線的原始平面缺陷（見圖13）。第一三輥三聯(lián)，其中包括首個(gè)矯正輥，平

94、整度控制在塑性變形程度為0.20至0.28的范圍內(nèi)。它適用于向上彎曲的鋼板，鋼板矯正后板向上方向退出，第二三輥三聯(lián)，其中包括兩個(gè)上輥和第二個(gè)輥，矯正后的平面塑性變形程度在0.28至0.38的范圍內(nèi)。在此范圍內(nèi)，向下彎曲幅度降低向上彎曲退出，以及矯正后鋼板向上彎曲的幅度減少。</p><p><b>　　圖14</b></p><p>　　第三個(gè)三聯(lián)，由第二個(gè)上輥和第二

95、第三個(gè)下輥組成，矯正后塑性變形程度在0.38至0.48范圍內(nèi)。向上彎曲的鋼板矯正后向上彎曲幅度增加。</p><p>　　設(shè)置進(jìn)入輥縫的變形適用0.48以上水平進(jìn)入下一個(gè)彎輥。這個(gè)彎曲幅度降低，直到?jīng)]有向上彎曲，微小塑性變形值為0.53時(shí)，鋼板完全平直。更大的塑性變形導(dǎo)致矯正后向下彎曲不斷變大，直至0.58的水平，相當(dāng)于向下彎曲0.0625英寸。在這一點(diǎn)上，下一個(gè)上輥應(yīng)用的是正的彎曲曲率，減小了向下彎曲的幅度。它

96、影響了在0.64處第二個(gè)重合點(diǎn)的產(chǎn)生。更大的塑性變形導(dǎo)致矯正后向上彎曲更加嚴(yán)重，在塑性變形程度為0.70處達(dá)到了最高值，為1.2英寸。</p><p>　　第四下輥，其適用于負(fù)彎曲曲率，減小了向上彎曲的幅度，第三個(gè)重合點(diǎn)發(fā)生在塑性變形程度為0.75處。這一矯正輥的影響持續(xù)到2.25英寸，相當(dāng)與塑性變形程度為0.80的位置。第四上輥控制這一點(diǎn)的曲率，一直到塑性變形程度為0.90時(shí)，并在0.85處產(chǎn)生了第四個(gè)重合點(diǎn)。

97、超越了塑性變形負(fù)彎曲曲率，減少了矯正后向上彎曲并在0.94處產(chǎn)生了第五個(gè)重合點(diǎn)。越大的塑性變形產(chǎn)生負(fù)的殘余曲率就越嚴(yán)重。</p><p>　　附加模擬的矯正機(jī)有著更多的矯正輥。同樣的三個(gè)條件，矯正前平整度用同一指標(biāo)（3/8英寸）和相同的屈服強(qiáng)度（50 ksi）在矯正機(jī)有著相同的矯正輥直徑（6英寸）和矯正輥輥距（10英寸）。進(jìn)行了關(guān)于13、15、17和19輥矯正機(jī)的模擬。兩個(gè)極端條件下，卷曲的鋼板（原始曲率半徑為1

98、5英寸）和作為冷軋和空冷的不連續(xù)矯正鋼板（原始曲率半徑為2000英寸）的結(jié)果，顯示在圖15上，其中11輥矯正機(jī)（圖15a和b），13輥矯正機(jī)（圖15c和d），15輥矯正機(jī)（圖15e和f），17輥矯正機(jī)（圖15g和h），19輥矯正機(jī)（圖15i和j）。</p><p>　　若干意見可以從這些模擬和表1中總結(jié)出來。隨著矯正輥的增加，發(fā)生了下列情況：</p><p><b>　　表1&l

99、t;/b></p><p>　　曲線左邊不重合，有所下降。顯示在較小的塑性變形程度下矯正后平整度缺陷減小。</p><p>　　直到更大的塑性變形，波動(dòng)才開始。峰值的幅度仍然是相同的，發(fā)生在更大的連續(xù)性變形上。將其移到右邊的圖表上。例如，表1上的向上彎曲的峰值為1.2英寸。對(duì)于原始曲率半徑為15英寸，它在11輥矯正機(jī)上塑性變形為0.70，15輥矯正機(jī)上為0.80，19輥矯正機(jī)上為0.