CN104951639A - Original furnace roller surface roughness optimizing method in specific process segment of annealing machine - Google Patents

Abstract

The invention discloses an original furnace roller surface roughness optimizing method in a specific process segment of an annealing machine. The method includes the steps that key equipment and process parameters of the annealing machine are collected; the furnace roller type and the elastic strip steel modulus of the strip steel covering part are calculated; traversal is conducted on the original furnace roller surface roughness within a certain value range, and the original furnace roller surface roughness with the minimum stable plate match aggregative indicator serves as the optimal value; spray coating is conducted on the furnace roller surface of the optimal original furnace roller surface roughness, and the maximum service mileage allowed by a furnace roller is made. Because the furnace roller surface roughness attenuation situation is fully considered, the purpose that the stable plate match performance of the strip steel keeps the best in the attenuation process of the furnace roller surface roughness serves as the target, and the optimized original furnace roller surface roughness value and the corresponding largest service mileage are determined, so that site production personnel can accurately master the furnace roller change time. The roller change frequency can be lowered, production efficiency is improved, and the stable plate match performance of the strip steel in the annealing machine is guaranteed.

Description

Connect the optimization method moving back furnace roller roll surface initial roughness in unit special process section

Technical field

The present invention relates to continuous annealing field, particularly relate to a kind of optimization method being suitable for even moving back furnace roller roll surface initial roughness in unit special process section.

Background technology

In cold rolling production procedure, connect and move back the significant points that unit becomes cold rolling organization of production gradually, and the stable directly impact of the equipment of stove section even moves back unit operation.In actual production process, the change of stove section furnace roller surfaceness connects to move back one of focal issue of unit trouble-free operation.Even moving back in unit furnace in each process section, in order to ensure that roll surface friction factor can meet the strip tension maintenance connecting and move back unit furnace subsegment, and the anti-bulk property of raising roll surface etc., the roll surface of stove section slewing rollers and idler roller all adopts plasma spray technology.

However, along with the increase of furnace roller military service milimeter number, the decay of its surfaceness is inevitable.According to correlation theory research and in-site measurement, furnace roller surfaceness attenuation process has variation tendency as shown in Figure 1.

As can be seen from furnace roller surfaceness die-away curve, roughness is at incipient stage t ₁be the Fast Wearing stage, because peak of profile is sharp-pointed, wearing and tearing are very fast, enter the stable wear stage t of a long term subsequently ₂and t ₃.Finally arrive roughness spot failure H, after rough surface spends H point, body surface damages rapidly, and produce pit, spot, develop into groove, roughness increases to R _ak.

Therefore, along with the continuous decay of furnace roller surfaceness, connect and move back unit furnace subsegment and often there will be the abnormal conditions such as tension force drop, strip running deviation time serious, can be caused to be close to, wrinkling until broken belt, directly affects the high-speed stable running of unit.Through theoretical research and in-site measurement, the decay of furnace roller surfaceness is the major reason causing tension force to drop.Scene often rule of thumb, by constantly changing furnace roller to keep the requirement to furnace roller roughness, reach the object of control stove section tension force drop, but, the initial surface roughness of newly changing furnace roller is not certain value, but the interior fluctuation of scope that larger, like this, just two problems is there is: one is when initial surface roughness reaches this range limit in actual production, on the one hand because larger roughness easily causes the generation of wooden dipper song, be unfavorable for stable logical plate, the roll change in advance when furnace roller still exists use ability on the other hand, add roll change frequency, serious have impact on production efficiency, two is when initial surface roughness is prescribed a time limit at the lower of this scope, not only because less roughness easily causes the generation of sideslip, be also unfavorable for stable logical plate, and, also likely because roll change not in time, causes strip running deviation to be close to, wrinkling until the generation of the industrial accidents such as broken belt.

In sum, excessive or the too small high-speed stable running being all unfavorable for unit of the initial surface roughness of furnace roller, be badly in need of the explicit value relative to its optimization one, under the prerequisite of the surfaceness attenuation law of known furnace roller, it is made to meet at furnace roller during one's term of military service, unit remains the state of at a high speed stable logical plate, and both ensure that production efficiency, turn avoid the generation of the accident caused not in time because of roll change.

Summary of the invention

The object of the invention is to solve prior art Problems existing, a kind of optimization method being suitable for even moving back furnace roller roll surface initial roughness in unit special process section is proposed, consider the decay of furnace roller roll surface roughness, under the prerequisite that the possibility of the industrial accidents such as band steel generation sideslip, wooden dipper song is minimum, by the optimization to furnace roller roll surface initial roughness, make furnace roller in maximum military service milimeter number, both reduced roll change frequency, enhance productivity, turn avoid the generation of accident.

The object of the invention is to be achieved through the following technical solutions:

An optimization method for furnace roller roll surface initial roughness in unit special process section moves back in company, comprises the following steps:

S1, key equipment and the technological parameter of unit move back in the company of collection, and definition optimization calculates correlation parameter;

The key equipment of unit moves back in described company and technological parameter comprises furnace roller roll forming parameter, is with steel parameter, bringing-up section parameter and annealing; Described furnace roller roll forming parameter comprises the most big roller footpath D of furnace roller ₀, furnace roller barrel length L, furnace roller land areas length S, furnace roller convexity δ; Described band steel parameter comprises the maximum temperature difference of strip width B, belt steel thickness h, band steel steel grade, belt steel surface roughness, supplied materials template data, bandwidth direction; Described bringing-up section parameter and annealing comprises technique initialization tension force σ, technique initialization temperature T;

Described optimization calculates correlation parameter and comprises furnace roller roll surface initial roughness Ra _r1, furnace roller roll surface initial roughness minimum value Ra _rmin, furnace roller roll surface initial roughness maximal value Ra _rmax, cyclic process iterations t ₁with t ₂, roughness adjustment step delta Ra _r, stable logical plate overall target mean value aver, current minimum stable logical plate overall target mean value aver ^*, current optimum furnace roller roll surface initial roughness stable logical plate overall target and value sum;

S2, according to the most big roller footpath D of described furnace roller ₀, furnace roller barrel length L, furnace roller land areas length S, furnace roller convexity δ, technique initialization temperature T, calculate band steel cover part furnace roller roll shape R _i(x _i) and band steel elastic modulus E (T);

S3, according to described furnace roller roll surface initial roughness minimum value Ra _rmin, cyclic process iterations t ₁and roughness adjustment step delta Ra _r, calculate furnace roller roll surface initial roughness, formula is Ra _r1=Ra _rmin+ t ₁Δ Ra _r;

Simultaneous Stabilization leads to plate overall target and value initialize 0, i.e. sum=0;

S4, according to described furnace roller roll surface initial roughness, obtains the maximum military service milimeter number of furnace roller under stable operation judge index by iterative computation, and obtains corresponding stable logical plate overall target and value sum;

S5, according to described stable logical plate overall target and value sum and cyclic process iterations t ₂calculation stability leads to plate overall target mean value aver, and computing formula is judge aver<aver ^*whether set up, if set up, perform assignment operation aver ^*=aver, continue to perform step S6, otherwise directly perform step S6;

S6, judges furnace roller roll surface initial roughness Ra now _r1whether meet Ra _r1<Ra _rmaxif meet cyclic process iterations cumulative 1, i.e. t ₁=t ₁+ 1, continue to perform described S3 step, otherwise finishing iteration calculates;

S7, exports current minimum stable logical plate overall target mean value aver ^*corresponding furnace roller roll surface initial roughness initial roughness value according to this optimum sprays furnace roller surface, and by known furnace roller surfaceness attenuation law aborning, formulates the maximum military service milimeter number that furnace roller allows.

Described step S4 comprises the following steps:

S41, according to described cyclic process iterations t2 and military service milimeter number adjustment step delta L, upgrade and calculate furnace roller military service milimeter number, computing formula is L=t ₂Δ L;

S42 is that L calculates furnace roller roll surface roughness Ra according to described military service milimeter number _r, computing formula is wherein B _lfor roll surface roughness attenuation coefficient, obtain the coefficientoffrictionμ between band steel under current furnace roller roll surface roughness and furnace roller by tabling look-up;

S43, according to the furnace roller roll shape R of described band steel cover part _i(x _i), band steel elastic modulus E (T) with technique initialization tension force σ, calculate strip tension distribution σ _iand maximum tension σ _max;

S44, according to described technique initialization tension force σ, strip tension distribution σ _i, maximum tension σ _max, coefficientoffrictionμ, strip width B and belt steel thickness h, calculate the bent index λ of strip running deviation factor ψ and wooden dipper, computing formula is:

$\mathrm{\&psi;}=|\text{'}2(\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i{x}_i-\underset{i=m+2}{\overset{2m+1}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i{x}_i)/(\mathrm{\&sigma;}\&CenterDot;B\&CenterDot;{\mathrm{\&mu;}}^a)+(\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i-\underset{i=m+2}{\overset{2m+1}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i)/(\mathrm{\&sigma;}\&CenterDot;{\mathrm{\&mu;}}^a)|$

$\mathrm{\&lambda;}=\frac{12{\mathrm{\&sigma;}}_{\max }\&CenterDot;(1+\mathrm{\&upsi;})B^2}{k_{\mathrm{cr}}{\mathrm{\&pi;}}^2{\mathrm{Eh}}^2}$

Wherein, m is the number of sampling on 1/2 strip width except band steel central point, x _ibe the distance of i-th sampling spot relative to furnace roller center, υ is band steel Poisson ratio, k _crfor band steel Critical Buckling index, a is friction factor Intrusion Index;

S45, judges whether strip running deviation factor ψ and the bent index λ of wooden dipper meets if meet, calculation stability leads to plate overall target φ, and formula is φ=A ψ/ψ ^*+ (1-A) λ/λ ^*, perform sum=sum+ φ, t simultaneously ₂=t ₂+ 1, then continue to perform described S41 step, otherwise finishing iteration calculates;

Wherein, ψ ^*for the critical sideslip factor, λ ^*for the bent index of critical wooden dipper, A is weighting coefficient.

The span of each parameter in described step S41 ~ S45: 500≤Δ L≤2500 ,-0.00004≤B _l<0,0<a<1,10 ³<k _cr<10 ⁴, 10< ψ ^*<50,0.5≤λ ^*≤ 1,0<A<1.

The value of each parameter in described step S41 ~ S45 is: Δ L=2000km, B _l=-0.00002, a=0.4, k _cr=10 ^3.38, ψ ^*=25, λ ^*=0.92, A=0.7.

Roughness adjustment step delta Ra in described step S3 _rspan: 0.1≤Δ Ra _r≤ 0.2.

In described step S1:

To the described equal initialize 0 of cyclic process iterations t1 and t2, i.e. t ₁=0, t ₂=0.

Beneficial effect of the present invention:

The optimization method of furnace roller roll surface initial roughness of the present invention, take into full account furnace roller roll surface roughness attenuation, keep being preferably target to be with steel stable logical plate in furnace roller roll surface roughness attenuation process, determine the furnace roller roll surface initial roughness value optimized and corresponding maximum military service milimeter number, make produced on-site personnel can the roll changing time of accurate assurance furnace roller.Compared with traditional knowhow, reduce roll change frequency, improve production efficiency, and band steel is guaranteed connecting the stable logical plate moved back in unit, table 1 for domestic certain connect move back unit furnace roller roll surface initial roughness optimize before and after condition of production contrast.

From table 1, during first arrival 2013 end of the year in 2012, after the optimization of furnace roller roll surface initial roughness, the accident frequency of unit obviously reduces, year output significantly improves, this mainly has benefited from: on the one hand by the optimization to furnace roller roll surface initial roughness, make unit remain at the stable state of relative high speed in furnace roller operation during one's term of military service; On the other hand, the accurate assurance of roll changing time is decreased to the incidence of accident, make unit obtain effective control because of the time waste that force outage causes, thus improve turnout.

Table 1 furnace roller roll surface initial roughness optimizes front and back condition of production contrast

Contrast before and after optimizing	The first quarter	For the second quarter	The third quater	The fourth quater	Total amount
						Accident frequency before optimizing/time	3	1	2	2	8
Accident frequency after optimizing/time	1	1	0	0	2
						Output (2012)/ten thousand ton before optimizing	14.2	15.8	12.6	13.3	55.9
Output (2013)/ten thousand ton after optimizing	14.4	16.5	16.8	15.4	63.1

For further illustrating above-mentioned purpose of the present invention, design feature and effect, below with reference to accompanying drawing, the present invention is described in detail.

Accompanying drawing explanation

Fig. 1 is furnace roller surfaceness die-away curve of the present invention;

Fig. 2 is the optimization method process flow diagram that furnace roller roll surface initial roughness parameter in unit special process section is moved back by company of the present invention;

Fig. 3 is the particular flow sheet calculating the maximum military service milimeter number of furnace roller under stable operation judge index in Fig. 2 flow process;

Fig. 4 is the band steel cover part furnace roller roll shape in specific embodiments of the invention;

Fig. 5 is furnace roller roughness in specific embodiments of the invention and the relation curve between friction factor;

Fig. 6 is the Tension Distribution curve of the band steel transverse direction in specific embodiments of the invention.

Embodiment

Accompanying drawing below in conjunction with embodiment is described in detail to the specific embodiment of the present invention.

Be the optimization method process flow diagram that furnace roller roll surface initial roughness parameter in unit special process section is moved back by company of the present invention see Fig. 2, Fig. 2, the optimization method of furnace roller roll surface initial roughness parameter in unit special process section moves back in company of the present invention, comprises the following steps:

S1, the company of collection move back key equipment and the technological parameter of unit, and definition optimization calculates correlation parameter;

The key equipment of unit moves back in described company and technological parameter comprises furnace roller roll forming parameter, is with steel parameter, bringing-up section parameter and annealing; Described furnace roller roll forming parameter comprises the most big roller footpath D of furnace roller ₀, furnace roller barrel length L, furnace roller land areas length S, furnace roller convexity δ; Described band steel parameter comprises the maximum temperature difference of strip width B, belt steel thickness h, band steel steel grade, belt steel surface roughness, supplied materials template data, bandwidth direction; Described bringing-up section parameter and annealing comprises technique initialization tension force σ, technique initialization temperature T;

Described optimization calculates correlation parameter and comprises furnace roller roll surface initial roughness Ra _r1, furnace roller roll surface initial roughness minimum value Ra _rmin, furnace roller roll surface initial roughness maximal value Ra _rmax, cyclic process iterations t ₁with t ₂, roughness adjustment step delta Ra _r, stable logical plate overall target mean value aver, current minimum stable logical plate overall target mean value aver ^*, current optimum furnace roller roll surface initial roughness stable logical plate overall target and value sum;

To described cyclic process iterations t ₁with t ₂equal initialize 0, current minimum stable logical plate overall target mean value initialize aver ^*=10 ¹⁰.

S2, according to the most big roller footpath D of described furnace roller ₀, furnace roller barrel length L, furnace roller land areas length S, furnace roller convexity δ, technique initialization temperature T, calculate band steel cover part furnace roller roll shape R _i(x _i) and band steel elastic modulus E (T).

S3, according to described furnace roller roll surface initial roughness minimum value Ra _rmin, cyclic process iterations t ₁and roughness adjustment step delta Ra _r, calculate furnace roller roll surface initial roughness, formula is Ra _r1=Ra _rmin+ t ₁Δ Ra _r;

Simultaneous Stabilization leads to plate overall target and value initialize 0, i.e. sum=0;

Roughness adjustment step delta Ra _rspan: 0.1≤Δ Ra _r≤ 0.2, the desirable Δ Ra of the present embodiment _r=0.1.

S4, according to described furnace roller roll surface initial roughness, obtain the maximum military service milimeter number of furnace roller under stable operation judge index by iterative computation, and obtain corresponding stable logical plate overall target and value sum, it comprises the following steps:

S41, according to described cyclic process iterations t2 and military service milimeter number adjustment step delta L, upgrade and calculate furnace roller military service milimeter number, computing formula is L=t ₂Δ L;

The wherein span of military service milimeter number adjustment step parameter: 500≤Δ L≤2500, desirable Δ L=2000km in the present embodiment;

S42 is that L calculates furnace roller roll surface roughness Ra according to described military service milimeter number _r, computing formula is the coefficientoffrictionμ between band steel under current furnace roller roll surface roughness and furnace roller is obtained by tabling look-up;

Wherein B _lfor roll surface roughness attenuation coefficient, span is-0.00004≤B _l<0, desirable B in the present embodiment _l=-0.00002;

The coefficientoffrictionμ between band steel under current furnace roller surfaceness and furnace roller can be obtained according to the relation between furnace roller roughness and friction factor;

S43, according to the furnace roller roll shape R of described band steel cover part _i(x _i), band steel elastic modulus E (T) with technique initialization tension force σ, calculate strip tension distribution σ _iand maximum tension σ _max;

According to elastic plastic theory, when the band steel elastic modulus E (T) under known Current Temperatures is σ with setting tension force, two relational expressions can be obtained: the 1) elongation of strip width direction each point and setting tension force σ, coefficientoffrictionμ, incoming profile ε _i, T is relevant for band steel transverse temperature difference Δ, and the elongation of strip width direction each point with furnace roller roll shape R _i(x _i) there is quantitative relationship; 2) mean value of the tension force of strip width direction each point equals setting tension force σ;

The Tension Distribution σ of band steel can be calculated thus _iand maximum tension σ wherein _max, σ _iexpression formula can be written as: σ _i=σ _i(R _i, σ, μ, ε _i', T, Δ T); σ _icalculating be known by those skilled in that art, although there is some pro forma difference to the expression of its computing formula in each list of references, but principle is all consistent, its computation process is not within the scope of the discussion of this case, therefore this case does not do too much explanation to it;

S44, according to described technique initialization tension force σ, strip tension distribution σ _i, maximum tension σ _max, coefficientoffrictionμ, strip width B and belt steel thickness h, calculate the bent index λ of strip running deviation factor ψ and wooden dipper, computing formula is:

$\mathrm{\&psi;}=|\text{'}2(\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i{x}_i-\underset{i=m+2}{\overset{2m+1}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i{x}_i)/(\mathrm{\&sigma;}\&CenterDot;B\&CenterDot;{\mathrm{\&mu;}}^a)+(\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i-\underset{i=m+2}{\overset{2m+1}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i)/(\mathrm{\&sigma;}\&CenterDot;{\mathrm{\&mu;}}^a)|$

$\mathrm{\&lambda;}=\frac{12{\mathrm{\&sigma;}}_{\max }\&CenterDot;(1+\mathrm{\&upsi;})B^2}{k_{\mathrm{cr}}{\mathrm{\&pi;}}^2{\mathrm{Eh}}^2}$

Wherein, m is the number of sampling on 1/2 strip width except band steel central point, x _ibe the distance of i-th sampling spot relative to furnace roller center, υ is band steel Poisson ratio, k _crfor band steel Critical Buckling index, a is friction factor Intrusion Index;

The span of each parameter: 0<a<1,10 ³<k _cr<104, desirable a=0.4, k in the present embodiment _cr=10 ^3.38;

S45, judges whether strip running deviation factor ψ and the bent index λ of wooden dipper meets if meet, calculation stability leads to plate overall target φ, and formula is φ=A ψ/ψ ^*+ (1-A) λ/λ ^*, perform sum=sum+ φ, t simultaneously ₂=t ₂+ 1, then continue to perform described S41 step, otherwise finishing iteration calculates;

Wherein, ψ ^*for the critical sideslip factor, λ ^*for the bent index of critical wooden dipper, A is weighting coefficient;

The span of each parameter: 10< ψ ^*<50,0.5≤λ ^*≤ 1,0<A<1, desirable ψ in the present embodiment ^*=25, λ ^*=0.92, A=0.7.

S5, according to described stable logical plate overall target and value sum and cyclic process iterations t ₂calculation stability leads to plate overall target mean value aver, and computing formula is judge aver<aver ^*whether set up, if set up, perform assignment operation aver ^*=aver, continue to perform step S6, otherwise directly perform step S6.

S6, judgement furnace roller roll surface initial roughness Ra now _r1whether meet Ra _r1<Ra _rmaxif meet cyclic process iterations cumulative 1, i.e. t ₁=t ₁+ 1, continue to perform described S3 step, otherwise finishing iteration calculates.

S7, export current minimum stable logical plate overall target mean value aver ^*corresponding furnace roller roll surface initial roughness initial roughness value according to this optimum sprays furnace roller surface, and by known furnace roller surfaceness attenuation law aborning, formulates the maximum military service milimeter number that furnace roller allows.

Below for embodiment explanation.

The practical application of moving back unit is connected for Baosteel Stainless Steel Co., Ltd..

Above-mentioned steps S1: key equipment and the technological parameter of unit move back in the company of collection, correlation parameter initialize.

Unit furnace roller roll forming parameter is moved back by this company: the most big roller footpath D of furnace roller ₀=900mm, furnace roller barrel length L=1950mm, furnace roller land areas length S=450mm, furnace roller convexity δ=3mm.

Band steel parameter: strip width B=1020mm, belt steel thickness h=0.5mm, band steel steel grade CQ, belt steel surface roughness Ra _r2=0.4 μm, supplied materials template data ε _i', the maximum temperature difference Δ T=40 DEG C of bandwidth direction.

Bringing-up section parameter and annealing: technique initialization tension force σ=7MPa, technique initialization temperature T=750 DEG C.

Correlation parameter initialize: given furnace roller roll surface initial roughness optimization range Ra _rmin=4 μm, Ra _rmax=5 μm, given parameters adjustment step delta Ra _r=0.1 μm, Δ L=2000km, cyclic process iterations t ₁=0, t ₂=0, critical sideslip factor ψ ^*=25, the bent index λ of critical wooden dipper ^*=0.92, current minimum stable logical plate overall target mean value aver ^*=10 ¹⁰, weighting coefficient A=0.7, band steel sampling spot number 2m+1=43, roll surface roughness attenuation coefficient B _l=-0.00002.

Above-mentioned steps S2: the furnace roller roll shape R calculating band steel cover part _i(x _i) and band steel elastic modulus E (T).

Furnace roller roll shape R _i(x _i) representing furnace roller radius corresponding to each sampling spot, it is the most big roller footpath D of furnace roller ₀, furnace roller barrel length L, furnace roller land areas length S, furnace roller convexity δ function, its functional expression can be expressed as: R _i(x _i)=R (x _i, D ₀, L, S, δ), as shown in Figure 4.

With the function that steel elastic modulus is technique initialization temperature T, the elastic modulus at corresponding technique initialization temperature is: E (T)=208639.8-0.21T ²=90754MPa.

Need to carry out iterative computation from step S3 to S6, provide value during first time iterative computation below.

Above-mentioned steps S3: calculate furnace roller roll surface initial roughness, i.e. Ra _r1=Ra _rmin+ t ₁Δ Ra _r=4 μm, Simultaneous Stabilization leads to plate overall target and value initialize 0, i.e. sum=0.

Above-mentioned steps S4, the maximum military service milimeter number of calculating furnace roller under stable operation judge index:

S41, upgrade and calculate furnace roller military service milimeter number, computing formula is L=t ₂Δ L=0;

S42, furnace roller roll surface roughness Ra when calculating military service milimeter number is L _r=Ra _r1× e ^-0.00002L, the coefficientoffrictionμ between band steel under current furnace roller roll surface roughness and furnace roller is obtained by tabling look-up;

Obtain out the coefficientoffrictionμ between band steel under current furnace roller surfaceness and furnace roller according to the relation between furnace roller roughness and friction factor, the relation in the present embodiment between furnace roller roughness and friction factor as shown in Figure 5.According to this relation, can obtain and work as Ra _r=Ra _r1× e ^-0.00002Lμ=0.2 when=4 μm.

S43, calculates strip tension distribution σ _iand maximum tension σ _max, the Tension Distribution curve with steel transverse direction in the present embodiment as shown in Figure 6, can try to achieve σ according to Tension Distribution curve _max=10.9MPa;

S44, calculates strip running deviation factor ψ and the bent index λ of wooden dipper:

$\mathrm{\&psi;}=\begin{array}{c}|2(\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i{x}_i-\underset{i=m+2}{\overset{2m+1}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i{x}_i)/(\mathrm{\&sigma;}\&CenterDot;B\&CenterDot;{\mathrm{\&mu;}}^a)+(\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i-\underset{i=m+2}{\overset{2m+1}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i)/(\mathrm{\&sigma;}\&CenterDot;{\mathrm{\&mu;}}^a)|\\ =|2(\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i{x}_i-\underset{i=m+2}{\overset{2m+1}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i{x}_i)/(7\&CenterDot;1020\&CenterDot;{0.2}^{0.4})+(\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i-\underset{i=m+2}{\overset{2m+1}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i)/(7\&CenterDot;{0.2}^{0.4})|=9.45\end{array}$

$\mathrm{\&lambda;}=\frac{12{\mathrm{\&sigma;}}_{\max }\&CenterDot;(1+\mathrm{\&upsi;})B^2}{k_{\mathrm{cr}}{\mathrm{\&pi;}}^2{\mathrm{Eh}}^2}=\frac{12\&times;10.9\&times;(1+0.3)\&times;{1020}^2}{{10}^{3.38}\&times;{3.14}^2\&times;90754\&times;{0.5}^2}=0.33$

Wherein, friction factor Intrusion Index a=0.4, band steel Poisson ratio υ=0.3, band steel Critical Buckling index k _cr=10 ^3.38;

S45, judges whether strip running deviation factor ψ and the bent index λ of wooden dipper meets obvious inequality is set up, then calculation stability leads to plate overall target, φ=A ψ/ψ ^*+ (1-A) λ/λ ^*=0.372, perform accumulating operation sum=sum+ φ=0.372, t simultaneously ₂=t ₂+ 1=1, then continues to perform described S41 step; Otherwise finishing iteration calculates.

S5, calculation stability lead to plate overall target mean value, judge aver<aver ^*set up? obvious inequality is set up, and makes aver ^*=aver=0.572, continues to perform step S6; If inequality is false, directly perform step S6.

S6, judge Ra _r1<Ra _rmaxset up? obvious inequality is set up, and makes t ₁=t ₁+ 1=1, proceeds to above-mentioned steps S3; If inequality is false, then proceed to step S7.

In the present embodiment, need to carry out 10 iterative computation (systemic circulation) from step S3 to S6, in each iterative computation, step S4 needs again successive ignition to calculate (partial circulating, step S41 ~ S45).

Provide the furnace roller roll surface initial roughness Ra in each systemic circulation iterative process below _r1, stable logical plate overall target mean value aver, and furnace roller military service milimeter number L, the strip running deviation factor ψ of the last iterative computation gained of partial circulating, the bent index λ of wooden dipper, stable logical plate overall target and value sum, result is as shown in table 2.

Each parameter result of calculation in table 2 each iteration

t 1	0	1	2	3	4	5	6	7	8	9	10
												Ra r1	4.0	4.1	4.2	4.3	4.4	4.5	4.6	4.7	4.8	4.9	5.0
L	18000	18000	18000	18000	20000	20000	20000	20000	20000	22000	22000
												ψ	29.5	28.82	28.27	28.05	27.84	27.64	27.58	27.38	27.16	26.83	26.41
λ	0.18	0.2	0.2	0.21	0.23	0.23	0.24	0.25	0.27	0.31	0.33
												sum	5.148	5.256	5.328	5.427	5.88	5.71	5.76	5.62	5.54	6.248	6.292
aver	0.572	0.584	0.592	0.603	0.588	0.571	0.576	0.562	0.554	0.568	0.572

S7, export current minimum stable logical plate overall target mean value aver ^*corresponding furnace roller initial surface roughness now t in corresponding table 1 ₁aver=0.554 when=8.

Initial roughness value according to this optimum sprays furnace roller surface, and by known furnace roller surfaceness attenuation law aborning, formulates the maximum military service milimeter number that furnace roller allows, and prescribes a time limit when reaching on this, timely roll change.

Those of ordinary skill in the art will be appreciated that, above embodiment is only used to object of the present invention is described, and be not used as limitation of the invention, as long as in essential scope of the present invention, the change of the above embodiment, modification all will be dropped in the scope of claim of the present invention.

Claims (6)

1. connect the optimization method moving back furnace roller roll surface initial roughness in unit special process section, it is characterized in that comprising the following steps:

S1, key equipment and the technological parameter of unit move back in the company of collection, and definition optimization calculates correlation parameter;

The key equipment of unit moves back in described company and technological parameter comprises furnace roller roll forming parameter, is with steel parameter, bringing-up section parameter and annealing; Described furnace roller roll forming parameter comprises the most big roller footpath D of furnace roller ₀, furnace roller barrel length L, furnace roller land areas length S, furnace roller convexity δ; Described band steel parameter comprises the maximum temperature difference of strip width B, belt steel thickness h, band steel steel grade, belt steel surface roughness, supplied materials template data, bandwidth direction; Described bringing-up section parameter and annealing comprises technique initialization tension force σ, technique initialization temperature T;

Described optimization calculates correlation parameter and comprises furnace roller roll surface initial roughness Ra _r1, furnace roller roll surface initial roughness minimum value Ra _rmin, furnace roller roll surface initial roughness maximal value Ra _rmax, cyclic process iterations t ₁with t ₂, roughness adjustment step delta Ra _r, stable logical plate overall target mean value aver, current minimum stable logical plate overall target mean value aver ^*, current optimum furnace roller roll surface initial roughness stable logical plate overall target and value sum;

S2, according to the most big roller footpath D of described furnace roller ₀, furnace roller barrel length L, furnace roller land areas length S, furnace roller convexity δ, technique initialization temperature T, calculate band steel cover part furnace roller roll shape R _i(x _i) and band steel elastic modulus E (T);

S3, according to described furnace roller roll surface initial roughness minimum value Ra _rmin, cyclic process iterations t ₁and roughness adjustment step delta Ra _r, calculate furnace roller roll surface initial roughness, formula is Ra _r1=Ra _rmin+ t ₁Δ Ra _r;

Simultaneous Stabilization leads to plate overall target and value initialize 0, i.e. sum=0;

S4, according to described furnace roller roll surface initial roughness, obtains the maximum military service milimeter number of furnace roller under stable operation judge index by iterative computation, and obtains corresponding stable logical plate overall target and value sum;

S5, according to described stable logical plate overall target and value sum and cyclic process iterations t ₂calculation stability leads to plate overall target mean value aver, and computing formula is judge aver<aver ^*whether set up, if set up, perform assignment operation aver ^*=aver, continue to perform step S6, otherwise directly perform step S6;

S6, judges furnace roller roll surface initial roughness Ra now _r1whether meet Ra _r1<Ra _rmaxif meet cyclic process iterations cumulative 1, i.e. t ₁=t ₁+ 1, continue to perform described S3 step, otherwise finishing iteration calculates;

S7, exports current minimum stable logical plate overall target mean value aver ^*corresponding furnace roller roll surface initial roughness initial roughness value according to this optimum sprays furnace roller surface, and by known furnace roller surfaceness attenuation law aborning, formulates the maximum military service milimeter number that furnace roller allows.

2. the optimization method of furnace roller roll surface initial roughness as claimed in claim 1, is characterized in that:

Described step S4 comprises the following steps:

S41, according to described cyclic process iterations t2 and military service milimeter number adjustment step delta L, upgrade and calculate furnace roller military service milimeter number, computing formula is L=t ₂Δ L;

S42 is that L calculates furnace roller roll surface roughness Ra according to described military service milimeter number _r, computing formula is wherein B _lfor roll surface roughness attenuation coefficient, obtain the coefficientoffrictionμ between band steel under current furnace roller roll surface roughness and furnace roller by tabling look-up;

S43, according to the furnace roller roll shape R of described band steel cover part _i(x _i), band steel elastic modulus E (T) with technique initialization tension force σ, calculate strip tension distribution σ _iand maximum tension σ _max;

S44, according to described technique initialization tension force σ, strip tension distribution σ _i, maximum tension σ _max, coefficientoffrictionμ, strip width B and belt steel thickness h, calculate the bent index λ of strip running deviation factor ψ and wooden dipper, computing formula is:

$\mathrm{\&psi;}=|\text{'}2(\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i{x}_i-\underset{i=m+2}{\overset{2m+1}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i{x}_i)/(\mathrm{\&sigma;}\&CenterDot;B\&CenterDot;{\mathrm{\&mu;}}^a)+(\underset{i=1}{\overset{m}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i-\underset{i=m+2}{\overset{2m+1}{\mathrm{\&Sigma;}}}{\mathrm{\&sigma;}}_i)/(\mathrm{\&sigma;}\&CenterDot;{\mathrm{\&mu;}}^a)|$

$\mathrm{\&lambda;}=\frac{12{\mathrm{\&sigma;}}_{\max }\&CenterDot;(1+\mathrm{\&upsi;})B^2}{k_{\mathrm{cr}}{\mathrm{\&pi;}}^2{\mathrm{Eh}}^2}$

Wherein, m is the number of sampling on 1/2 strip width except band steel central point, x _ibe the distance of i-th sampling spot relative to furnace roller center, υ is band steel Poisson ratio, k _crfor band steel Critical Buckling index, a is friction factor Intrusion Index;

S45, judges whether strip running deviation factor ψ and the bent index λ of wooden dipper meets if meet, calculation stability leads to plate overall target φ, and formula is φ=A ψ/ψ ^*+ (1-A) λ/λ ^*, perform sum=sum+ φ, t simultaneously ₂=t ₂+ 1, then continue to perform described S41 step, otherwise finishing iteration calculates;

Wherein, ψ ^*for the critical sideslip factor, λ ^*for the bent index of critical wooden dipper, A is weighting coefficient.

3. the optimization method of furnace roller roll surface initial roughness as claimed in claim 2, is characterized in that:

The span of each parameter in described step S41 ~ S45: 500≤Δ L≤2500 ,-0.00004≤B _l<0,0<a<1,10 ³<k _cr<10 ⁴, 10< ψ ^*<50,0.5≤λ ^*≤ 1,0<A<1.

4. the optimization method of furnace roller roll surface initial roughness as claimed in claim 3, is characterized in that:

The value of each parameter in described step S41 ~ S45 is: Δ L=2000km, B _l=-0.00002, a=0.4, k _cr=10 ^3.38, ψ ^*=25, λ ^*=0.92, A=0.7.

5. the optimization method of furnace roller roll surface initial roughness as claimed in claim 1, is characterized in that:

Roughness adjustment step delta Ra in described step S3 _rspan: 0.1≤Δ Ra _r≤ 0.2.

6. the optimization method of the furnace roller roll surface initial roughness as described in as arbitrary in Claims 1 to 5, is characterized in that:

In described step S1:

To the described equal initialize 0 of cyclic process iterations t1 and t2, i.e. t ₁=0, t ₂=0.