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附录 1 冷轧横向偏移量的控制性能

摘要

一些先进的轧机考虑到工作棍和支撑棍在板带所在平面内的偏移量,允许棍在三个方向变形。这个模型用来探究冷扎横向偏移量控制系统的灵敏度对冷扎三个方向精度的影响。它最终揭示水平工作棍偏移量的影响最大,构成了主要激励。这种影响随偏移的程度和工作棍的直径的变化而变化,而激励的主要成分的影响尤其显著。另外,水平轧制偏移量本身可以成为激励信号,尽管它的灵敏度大大的改变了偏移程度。

1.引言

板带材冷扎机的设计需要在两个物理因素之间协调衡量:当增大轧辊直径时,总轧制力会增大;当减小轧辊直径时,变形量又会增大。轧辊的变形使板带的材质不均匀性减小,但是使产品的外形尺寸精度和平面度得不到保证。设计轧机时应协调这些因素,并应通过可控制的激励对因材料不均匀性引起的变形进行补偿。一些更先进的轧机允许工作棍或支撑棍在水平面内可控制的窜动,这是靠轴承在与被轧板带平行的平面内移动实现的。图 1 示意了这个过程。这样的水平窜动是为了更好的保证被轧板带的平面度,但是没有专著论述这种方法,因为这方面的论文都假定所有的轧辊都在一个平面内。但是事实上,轧机的轧辊即使没有任何的滚动偏移,也会因为摩擦力的不平衡在水平面内变形。已经发表了的关于轧制偏斜的分析论述中最早的是 Townsend 和 Shohet,他们的模型已经大大扩展并得到了广泛印证。他们的方法是把所有偏斜向轴向和水平方向分解,再用数学方法描述每一种变形。Pawelski, Rasp 和 Rieckman 证实了这种模型适用于六棍轧机,而且他们和 Wang, Pan 证明了连续不确定变化拱形是怎么形成的,在这里,一对扎根反对称拱形轴向窜动可以被联系起来。这些模型都是用简单的一维形式,建立在与轧辊和轧辊变形都垂直的方向上。更精确一点,板带对轧辊的压力场应该是二维的,为此 Berger Pawelski 和Funke 给出了轧辊表面压扁率这样一个更精确的描述。所有这些模型都遇到了同样的难题,就是用数学模型来表示不同的激励形式引起的轧辊之间的变形。Allwood 和 Bryant 论证了怎样借鉴 Allwood, Bryant 和 Stubbs解决接触问题的方法,用简单的运算法则把Shohet 和Townsend 的模型转化为矩阵问题。Hacquin,Montmittonet 和 Guillerault 给出了用这些近似方法预测外形和有限元分析之间的详细对比,得出两种方法高度一致,但是也得出了卷端影响由两个修正因

素引起。

2.轧辊系模型和水平偏移量

轧辊系模型和水平偏移量 所有现有的轧棍系模型都可以用数字矩阵来描述,每一个位置对应一个轧辊表面或轧辊之间的接触面。这种矩阵通过简单的力分解以向量和线性的有特定意义的复数记录和描述。一个典型的这样的表面位置计算应该做下面的变形

123422()x A f f A u A u

y r A f x

=+++=++

其中,x 是描述分布式轧辊轴位置的量 y-描述轧辊表面与其他部件接触部分的位置

2f -描述由变量y 确定的接触面上的垂直力

1f -描述除由变量y 确定的表面以外的任何表面的垂直力, 例如轧辊之间的接触力

u- 描述轧辊轴承上的力

v -描述轧辊轴端上点的位置

r -描述轧辊的变形(在轧辊长度方向上的直径变化)

1A -描述轧辊轴的大的变形,一般是将梁弯曲的理论加以修正用于计算大直径的轧辊轴的变形

2A -描述轧辊表面的局部变形, 一般是用Boussinesq 理论, 假设力只作用于一点,而表面是无限大平面

3A -描述由于轧辊轴承受力而引起的变形

4A -给出了轧辊轴端两点之间的线插补。轧辊堆叠模型建立的条件是必须保证轧辊之间或轧辊与其他部件之间不能粘连或者相互压入。这里的第二个条件需要模型解决这样一个问题,假设部件a 和b(假定a 在b 的上面),则它们之间的距离d 应满足:

(2) lower upper a b

d y y =-

00d f ≤≤00d f

≤≤ 在这里,y 表示的两个表面位置可由式(1)计算得出。 如插图2所示。方法预测外形和有限元分析之间的详细对比,得出两种方法高度一致,但是也得出了卷端影响由两个修正因素引起. 假定在每一个取样点,表面张力和分离距离d

都是零,则公式(2)可以方便的表示为:

()00()Cd I C f I C d Cf +-=≤-=()00()Cd I C f I C d Cf

+-=≤-= 这里,C 是一个对角矩阵,在表示接触面的位置都是1,其他位置都是0,Z 是单位矩阵。用公式(2)中的第一个式子和公式(1)中的两个式子可得,轧辊间距d 在公式(3)中可表示为线性的力分布,因此,轧辊堆叠模型就可以解决了。接触线长度取决于被轧件的布置形式,所以矩阵C 必须在模型解决方法中确定。

2.1轧辊的三维变形轧辊的三维变形

轧辊的三维变形已由Stubbs 给出,在这一节会详细介绍。如图3所示,两个没有变形的轧辊是平行排布的,当轧机运转,压力作用在轧辊上,轧辊之间靠分布的摩擦了传递扭矩。在这两个力的作用下,轧辊在水平垂直方向均变形,以至于相互“缠绕”。这种“缠绕”可用两个相互垂直平面之间的夹角和接触线长度沿轧辊轴向的变化来表示。

通过轧辊的一部分,图4a 表示了轧辊表面的力,图4b 表示了轧辊的相互变形。在相互接触的表面存在着沿接触线方向分布的接触力。可以假设力只沿轧辊轴向分布,但是那样的话将转化为二维问题。电机驱动一个轧辊,在轧辊之间产生剪力。图4a 也表示了轧辊除了受压以外,还要受到上面或下面部件的摩擦力。 图 3 水平偏移轧辊于相邻轧辊的扭曲 根据现有的垂直模型,轧辊变形包括局部表面压扁和轴向变形,而在交界面上,公式(2)的两个条件中的一个必须得到满足。在轧辊 a 和 b 接触的区域接触力需进行分解,如图四 b 所示,沿水平和垂直方向分解为.轧辊间距是沿轧辊轴纵向量取的,

所以 cos va vb d y y θ=-

其中,cos θ 被假定为一个对角矩阵。

表面张力的作用方向平行于 d ,因此表面位置 y 和轴向位置 x 有如下关系,

2252cos ()va va a a a y x r A f A t θ=---

2252cos ()vb vb b b b y x r A f A t θ=+--

其中,5A 示摩擦力 t 引起的表面变形。

为了确定轧辊系中每一个轧辊的变形位置,假定所有变形都可以分解为水平和垂直两个方向。 Hacquin , Montmittonet 和 Guillerault 进行了校验工作,因此这种做法被认为适用于轧辊偏斜的计算。同样的影响函数矩阵用来表示垂直

和水平方向。

134,,A A A 用来 表示垂直和水平方向 。

对公式(1)进行简单的符号扩展,并且沿滚轴的轴向分解力

2222111111112222134134(cos sin )(cos sin )

(cos sin )(cos sin )

v h v v v v

h h h h

f f t f t f t f t f x A f A u A v x A f A u A v θθθθθθθθ=--+=-++=++=++

Vh 表示轧辊轴承的水平偏移量,在本文中不考虑这个量的影响。解决堆叠模型中的偏移和扭曲需要把公式(6)代入到公式(5)中,再把公式(5)代入到公式(4)中,再和公式(3)相比较来解决。如前文所述,轧辊平衡和板带所受名义约束也应考虑。 2.2 轧辊之间的摩擦力轧辊之间的摩擦力

大多数的轧辊部件都是靠电机带动一对轧辊,一般是支撑棍。电机的扭矩靠轧辊之间的摩擦力传递到工作棍, 这就是前一小节提到的力 t.这些力可以在库仑定律中找到,在该定律中为了加强对不受电机直接带动的轧辊的扭矩的平衡,乘上了系数ρ.很显然,这种摩擦力的存在不完全是因为轧辊轴承存在摩擦阻力,所以有摩擦定律,

t mf μ=

对角矩阵 m 是对摩擦力的分布的平均值的描述。

2.3 模型的迭代解法模型的迭代解法

如果正确的扭转角被确定出来,它将满足关系:

2tan()()/()ha hb va vb x x x x θ=-- (8)

其中, ‘./’是由被分解的元素决定的。轴向位置矩阵 x 是由公式(6)计算出来的。然而在最初只有θ 的估计值θ 是已知的,而且需要通过解决模型来修正改估计值,并且要用到公式:

12arctan ()/()hb va vb

n n n n n ha x x x x θ+⎡⎤=--⎣⎦ (9) 其中n θ 是对θ 的 n 次估计。运用这种方法会发现,各个角度迅速收敛于一个相对精确的值。 重复迭代需要解决图五所示的接触力矩阵C 和扭转角θ 的问题。内部循环则类似于现有的垂直轧辊系模型。3.横向控制分析横向控制分析

横向轧制参数要么通过轮廓扫描仪测板厚,要么通过测板带平面内的残余应力来确定。测出的测量值相对于参考值(通常是 0)的偏差被反馈到调整轧辊系动力部件的控制端。控制端响应的稳定性和精度取决于可预知的动力部件的灵敏

度。

为了深入了解板带材控制系统的内部结构,下面提到由 Duncan , Allwood 和 Garimella [lo]提出的方法。如果用γ 表示板带的纵向距离,对动力部件 j 的响应()j g r 可以简单的表示为,

,0

()()j

N j i j i i g r c r φ==∑ (10) 其中, 是,i j c -延展系数, ()i r φ-是主函数,一个 Chebyshev 多项式。激励来源于轧辊弯曲和热胀冷缩等物理效应,所以激励的响应不大可能包括高频的成分,这一观点证实了上述论断。计算过程中21j N =的值将被用到。系数,i j c 的量

级将被以频谱的形式描述,利用频谱图来研究响应的内部结构。

被加工板带的侧面在宽度方向的厚度变化和纵向平面内的残余应力这两个交叉的参数决定的板带的质量。计算这两个参数需要一个和轧辊系模型想匹配的板带变形模型。这方面的研究早在三十年前就已经大规模投资进行,但是实际中可以和轧辊系模型相匹配的精确板带模型研究发展的太慢了。于是用到一种将板带看成是平行的薄片的近似模型。这种近似模型在板带的大部分部位足够精确,但是在边缘部位就不精确了。这个模型还给出了平面和轮廓之间的线性关系,所以只考虑平面就可以了。

表一:轧辊系模型试验的几何数据

工作棍直径,cm 50――100

中间棍直径,cm 100

支撑棍直径,cm 200

轧辊长度,cm 400

轧辊支撑之间的距离,cm 500

板带宽度,cm 350

入口厚度,mm 23

出口厚度,mm 15

总轧制力,t 4750

中间棍水平偏移量 0

工作棍水平偏移量,cm -12.5――12.5

水平轧辊偏移的影响将通过表一中的六棍系和板带几何数据给出。轧辊轴的硬度与直径的四次方成正 比,水平偏移的的主要影响与工作棍有关,而相对于支撑棍,中间棍的影响可以忽略不计。假定轧辊系有六个横向控制激励:

(1) 工作棍水平压力

(2) 中间棍水平压力

(3) 中间棍水平窜动

(4)工作棍相对于支撑棍两侧的水平偏移

(5)工作棍的可控顶喷冷却的理想精确响应

(6)中间棍的可控顶喷冷却的理想精确响应

将频谱值代入公式(10)并比较可得出各个激励对板带平面度的影响。4.结果和讨论结果和讨论

图 6 给出了在第三节列出的各个激励在给定点对平面度影响的范围。所有的插图频谱都由有对称效应的激励的偶分支决定,所以偶次多项式的系数决定了它们的分解结果。对于四个主要的激励,它们的响应受控于第二,第四多项式。另外两个较分散的激励则有更复杂的响应。对于每一个激励,图六都给出了三个包迹图。中间的狭长带显示了频谱是由二维的轧辊系模型得到的。上下两个宽带显示的是工作棍水平偏移的端点值和工作棍直径。很显然工作棍的水平偏移对激励的灵敏度有很大的影响。例如,考虑到中间棍弯曲的影响,会得到灵敏度由其它的小扰动影响的二维结果。与此相反,如果存在工作棍水平偏移,则灵敏度会出现出新组分。

图 6 表示中间棍激励的灵敏度是如何受(a)工作棍直径(也与中间棍有关)和(b)水平偏移的影响而改变的。瀑布似的图形表示了灵敏度大小沿板带边沿的变化,图 6b 则给出了大的负偏移的四次多项式响应和主要的正偏移响应。

如图六所示,所有激励的响应都是二次或四次多项式。图 7 和图 8 给出了这两个组分的频谱是如何随工作棍直径和它的水平偏移量的变化而变化的。在本模型中,表面也被进行二维处理,因此当水平变形被忽视时,任何相对于零偏移的背离都将视为是不精确的。

图 7 和图 8 显示,激励的响应主要受工作棍的水平偏移的影响。而受分散的激励(例如‘震颤’)的影响很小。在这两种情况下,都是较细的负偏移的轧辊的响应改变量大。表面区域的重要性表现在,在六棍轧机中只驱动支撑滚,中间棍和工作棍之间的摩擦力是沿工作棍变形的反方向的。如果工作棍正偏移,则由中间棍承担变形力,但是如果工作棍负偏移,则变形量会减小甚至会脱离中间棍。这种情况会很糟糕,但是实际上是不会出现的,因为这样的话就会出现工作棍和中间棍之间的剧烈震颤。

图 7a—c 和图 8a—c 表示了轧辊偏移影响着主要激励。但是图 7 却给出了虽然对于大部分典型响应,偏移量影响的响应的大小,不过在二维范围内有20%左右的响应不受偏移量影响,有些甚至发生在工作棍。总之,轧辊直径的对激励的影响相对与偏移量要小的多。

最后,图 6 和图 7d 证实了,工作棍水平偏移有可能成为有用的激励。平面度的变化和和工作棍偏移有很相像的构成,在极端情况下都包含四次组分。不

像其它的激励,灵敏度的大小主要依赖于偏移量,当偏移由正变为负时,灵敏度符号也改变。

5.结论

本文以公式的形式给出了现有的二维轧辊系模型可以延拓为允许轧辊在板带所在平面内变形。试验数据没有进一步验证,但是显然对于现有的轴向部件模型,该模型的精度已经足够用了。

水平棍偏移的影响取决于轧辊直径和偏移的方向。对于主要的激励,当工作棍中心没有被中间棍很好的固定时,逆向的水平工作棍偏移将使灵敏度的增加。对于其它的激励,逆向水平偏移的影响更大,但是却更不利于提高灵敏度,因为,工作棍直径的小的震颤的影响是工作棍缠绕中间棍,并且板带的凸凹减少。没有考虑轧辊间摩擦力的二维轧辊系模型会得出激励灵敏度的错误结果,导致控制性能的退化和延缓。而且,水平工作棍偏移也有可能成为激励,但是它的响应的大小显著的受偏移量的影响。

轧机用弹性阻尼体减震

2.1 弹性阻尼体技术在轧机上的应用

轧机的轧辊平衡分离装置是轧机的重要组成部分。长期以来,该装置采用传统的弹簧、橡胶垫、液压等平衡装置,实践中发现采用这些平衡方式存在许多弊端,如弹簧平衡压下不足、易损坏、过钢时跳动严重,影响产品精度;橡胶垫平衡,平衡力过大,常因轧辊产生挠度而断辊;液压平衡环节过多、故障频繁、易污染等。为了合理的解决这一问题,欧洲轧机制造厂家于1964年推出了基于弹性阻尼体技术生产的轧机用阻尼平衡减震器,该减震器的体积小、使用方便、承载力大、寿命长、工作稳定、无需外接设备,很快为许多钢铁企业所接受。

2.2 弹性阻尼体技术及其应用

2.2.1 弹性阻尼体性能

弹性阻尼体是一种由多种化合物合成的高分子材料,该材料于 1964 年首次被用于工业减震器的设计开发,并在其后的几十年中不断完善和发展。今天,弹性阻尼减震、缓冲技术已经成为国际公认的成熟技术,并被许多诸如马来西亚等著名生产厂家直接设计选用。

2.2.1.1 粘性

性阻尼体可产生极强的粘稠摩擦力,吸收活塞运动时外力所产生的巨大能量,这种特性使减震器或或缓冲器具有特殊的减震缓冲功能。

2.2.1.2 可压缩性

当弹性阻尼体受到很大外力时,其体积缩小、收缩部分体积与液体相似,其收缩率可达 15%,这种特性使它具备了优于弹簧的功能。以上特点决定了弹性阻尼体可被置于一密闭容器中,以一定的机械结构来实现其减震、平衡、缓冲功能,采用这一技术生产出的弹性阻尼体减震缓冲产品性能良好,贮能大,无须维修,无老化现象,工作可靠,易于安装,并可省去其它类缓冲减震器所需的弹簧预应力装置、外部电源等辅助设备,其优点是显而易见的。

2.2.2 弹性阻尼体的制备及性能特点

弹性阻尼体母体是由精选的多种化工原料合成稳定的高分子化合物后,经水解、裂解,然后在催化剂作用下,进行离子型开环聚合而成的性能稳定的高分子化合物。母体制成后,需经过补强、抗老化、增粘等多道工序,以完善其各项物理指标性能。最后配置出的高分子化合物为酮类制品,根据不同需要,分子量稳定在 40 万-70 万之间,以聚合物形态出现,呈鲜红色半流体状,静置后,表面呈现金属光泽。

特性 :

(1) 高粘性

(2) 强压缩性

(3) 良好的热稳定性

(4) 特殊的化学惰性

(5) 无老化现象

附录2 外文文献原文

Elastic damping material shock absorber for rolling mill

2.1 The application of elastic damping material technique in

rolling mill

Roll balance dividing device is the important part of rolling mill. For a long time, the device uses traditional balance ways, such as spring, rubber backing

and hydraulic etc. there are many problems in practice by using these balance ways, for example, the pressing force of spring is not insufficient, it is easy to damage and move up and down seriously when rolling so that affect the product

precision; using a rubber backing to balance, the balance force is too large ,the

roll often break because it has deflection; hydraulic balance has too many links

so that troubles often arise and it is easy to pollute. In order to solve these problems, rolling mill in 1964 which was on the basis of elastic damping technique, the shock absorber has a small volume, large load-carrying ability and long service life, it was easy to use ,worked stably and didn’t need external device, it was accepted by many iron&steel enterprises soon.

2.2 The brief introduction of the elastic damping technology&application

2.2.1 The property of elastic damping materials

Elastic damping material is a macromolecule material synthesized by

many compounds, it was first used for industrial shock absorber in 1964 and has been continually improved and developed in the past decades. Today, elastic damping shock absorbing and suffering techniques have become international acknowledged mature techniques and have been used by many famous machinery manufactures, such as SMS Schloemann-Siemag AG.

(1) Viscosity

The viscosity of pasty elastic material can produce very strong stick friction

and absorb tremendous energy produced by external force when piston moves, this special property makes shock absorber or buffer have special damping and buffering functions.

(2) Compressibility

When elastic damping material is exerted a very big external force, its volume contracts, the volume of contracted part is similar to liquid, its contraction can reach 15%.The special property makes its function better than

spring.

2.2.2 Preparation of elastic damping materials and their property

The mother body of elastic damping material is a stable macromolecule compound, after it is synthesized by many kinds of carefully chosen industrial chemicals, through hydrolysis and crack then under the action of catalyst, make

ionic open-loop polymerizing. After the mother body is finished, supplying intensity, anti-ageing and adding viscosity etc. many processes are needed to

perfect its different physical properties. Last finished macromolecule compounds are ketonic products, according to different requirements, their molecular weights are between 4 hundred thousand-7 hundred thousand, they appear in polymer form and scarlet, half fluid, put them aside for a while, their surface shows metallic luster.

Special properties:

(1) High viscosity

(2) Strong compressibility

(3) Good thermal stability

(4) Special chemical inertia

(5) Without ageing phenomenon

2.3.1 High energy elastic damping disc shock absorber

High energy elastic damping material disc shock absorber produced by Jerrat (shorter form: disc shock absorber) are annular high energy damping shock absorber, its structure is compact and there is shock absorbing need in the direction of axial. Compared with disc spring, disc shock absorber eliminates

complicated process of superposition mounting, its mounting is simple and doesn’t need to maintain. Because it realizes shock absorbing way with a shock

absorbing instead of steel springs superposition, so its advantages of rigidity,

ageing resistance stable mechanical property shown in practice are beyond comparison. Excellent properties of elastic damping materials enable disc shock absorber to satisfy big load shock absorbing requirement at very small volume

so that effectively save design space. Its these good properties are also suitable

for the anchor bolt shock absorbing etc. situations.

2.3.2 High energy damping buffer

2.3.2.1 Basic principle

By the action of dynamic applied force, the fast insertion of piston will result in steep increase of friction between piston and damping material and piston rod is decided by moving speed, both are in direct proportion. The friction between solid sealing parts is decided by internal pressure, i.e., the larger internal

pressure is, the larger friction is (the pressure is produced by compressing the volume of elastic material chamber). This shows that high energy damping buffer makes full use of compressibility and high viscosity of elastic damping

medium, it converts instantaneous impact energy into elastic potential energy(produced by compressing medium)and thermal energy(produced by friction)and rapid release. High energy damping buffer made by using above principle has strong buffering ability, and its volume is small, weight is light, its buffering energy is 3 times of which rubber buffer had at same volume, the highest energy absorptivity can reach 85%.

2.3.2.2 The advantages of products

Compared with rubber buffer, high energy damping buffer can resist high temperature and corrosion, can suit adverse circumstances, it has strong rigidity

and high shock strength, it works stably and has no ageing and failure phenomenon. Compared with traditional pneumatic buffer and air oil buffer or hydraulic buffer, it is easy to mount ,its structure is compact, volume is small, weight is light and service life is long, it doesn’t need daily maintenance. Because it has fewer sealing links and is not easy to damage, it is more suitable for high temperature circumstances in which pneumatic buffer and hydraulic buffer can not work, and it doesn’t need other complicated auxiliary devices, it has no air leak and oil leak phenomenon, it works stably and reliably. 2.3.2.3 Scope of application High energy damping buffers have been widely applied in iron&steel industry and heavy machinery industry, such as: buffer for baffle plate and loop in rolling mill, for adjustable end stop, for limits of soaking hood and various moving machinery, lifting machinery etc. many places where buffering and guard are needed, the use result is very ideal, they can increase collision safety coefficient of equipment with the highest limit at a limited design

space and guard the main equipment well.

外文翻译外文文献英文文献国际建设工程风险分析

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[1] 王起江,洪杰.超超临界电站锅炉用新型管材的研制[J].宝钢技术,2008(5): 44-53. [2] 王起江,邹凤鸣.T91高压锅炉管的研制与应用[J].发电设备,2005 (1): 43-47. [3] Fujio Abe.Bainitic and martensitic creep-resistant steels[J].Solid State and Materials Science,2004,8:305-311. [4] 马明编译.美国新的超临界机组考虑使用T/P92的原因[J].电力建设,2006, 27(11):79-80. [5] 戴平.国产P91钢管道存在的问题及其解决[J].广东电力,2008,21(8): 67-69. [6] 田党.关于难变形钢和合金管坯的二辊斜轧穿孔问题[J].钢铁,1998,33(1): 33-36. [7] P J Ennis,A Czyrska-Filemonowicz.Recent advances in creep-resistant steels for power plant applications [J].Sādhanā,2003,28:709–730. [8] 刘立民,朱洪,刘志国.法国T91、P91钢管性能评定[J].电站系统工程, 2002,18(1):63-64. [9] 彭孙鸿.T91钢管在我国的应用前景[J].宝钢技术,1997,6:48-50. [10] H.C. Furtado,L.H. de Almeida,I. Le May.Precipitation in 9Cr–1Mo steel after creep deformation[J].Materials Characterization,2007,58:72–77.[11] 蒯春光,彭志方.T/P91钢在450-1200℃区间各相元素的分配特征及相稳定 性[J].金属学报,2008,44(8):897-900. [12] 孙智,董小文,张绪平,等.奥氏体化温度对9Cr-1Mo-V-Nb钢组织与性能 的影响[J].金属热处理,2001,26(8):12-14. [13] 刘靖,周立新,傅晨光,等.电站锅炉用T91钢热穿孔性能的研究[J].钢 管,2002,31(5):9-11. [14] 彭孙鸿,尤夙志,姜明娟,等.热穿孔温度对T91持久强度的影响[J].特 殊钢,2001,22(2):10-12. [15] 崔光珠,朱伏先,高德福,等.T91钢高温变形特性研究[J].塑性工程学 报,1999,6(2):13-16. [16] 余勇,周晓岚,赵志毅,等.T91变形抗力模型建立及理论轧制压力计算[J].宝 钢技术,2006(3):31-34. [17] Polcik P,Sailer T,Blum W,et al.On the microstructural development of the tempered martensitic Cr-steel P91 during long-term creep[J].Materials Science and Engineering,1999,260:252-259.

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