CN101745548A - Finite element correcting method of deformation resistance of non-oriented electrical steel in CSP (cast steel plate) production line - Google Patents

Abstract

The invention discloses a method for correcting deformation resistance generated by the CSP (cast steel plate) production line non-oriented electrical steel in the process of the tandem rolling of seven racks, belonging to the technical field of rolling. The method comprises the following steps of: (1) collecting detected real rolling force data; (2) introducing the detected real rolling force data into a Sims unit rolling force formula to deduce out an initial value of the deformation resistance; and (3) correcting the initial value of the deformation resistance. By using a field actual production technology parameter as an input value in a finite element model, the method is close to an actual production environment and can truly reflect the changing conditions of the deformation resistance in the rolling of each rack; the method can optimize a two-stage system deformation resistance model; and through optimizing the set value of the rolling force by using the corrected deformation resistance value, the method can improve the preset precision of the rolling force, ensure the stable rolling process and improve the product quality.

Description

CSP production line non-oriented electrical steel resistance of deformation finite element revised law

Technical field

The present invention relates to the method that a kind of resistance of deformation that CSP production line non-oriented electrical steel is produced is revised in seven frame continuous rolling process, belong to rolling technical field.

Background technology

The metal deformation drag is a fundamental quantity that characterizes the steel pressure machining characteristics, correctly determines metal deformation drag under the different distortion condition, is the necessary condition that improves the tandem mill control accuracy.In the past when setting up the relational model of resistance of deformation and deflection, deformation velocity and temperature, adopt multiple nonlinear regression method that the data of actual measurement are handled usually after, obtain corresponding deformation resistance model structure.When adopting this method modeling, to make hypothesis (as common employing exponential type function) to the type function of deformation resistance model, and in fact the Changing Pattern of resistance of deformation can not be in full accord with selected type function on a large scale, when particularly considering factors such as static crystallization again, strain accumulation, dynamic recrystallization, phase transformation to the influencing of resistance of deformation, deformation resistance model is difficult to describe with selected function especially, thereby adopts this method to calculate resistance of deformation and certainly will bring the bigger error of calculation.In addition, conventional variety band steel is in the hot continuous rolling process, its resistance of deformation mainly concentrates on the austenitic area, so rolling Mathematical Modeling, deformation resistance model particularly, usually just consider the influence of the distortion of austenitic area to resistance of deformation, and non-oriented electrical steel, the silicone content height because carbon content is low, and phase transformation temperature points height, distortion in the hot continuous rolling process is not only carried out in austenite, but also in two-phase section and ferrite area, carry out, and the flow stress of the flow stress when ferrite area is out of shape when being out of shape with the austenitic area is significantly different, and therefore when rolling non-oriented electrical steel, the resistance of deformation that deformation resistance model calculates is inaccurate, causing resistance of deformation to be brought into rolling force model presets when calculating, result of calculation and actual roll-force almost differ one times, have increased difficulty for the steady production of non-oriented electrical steel, have had a strong impact on the quality of production of non-oriented electrical steel.Therefore be necessary the deformation resistance model of non-oriented electrical steel is revised, thereby guarantee the degree of accuracy that roll-force is calculated.

In the operation of rolling, roll-force is to show influence to strip crown by the degree of disturbing of roller system distortion, roll, roll flattening etc., strip crown is influenced slowly outside the disturbance factor ignoring, and the variation of strip crown mainly is subjected to the influence of roll-force.Under the prerequisite that guarantees good strip crown index, can be by strip crown correction resistance of deformation initial theory calculated value, and then, guarantee the setting accuracy of roll-force by the rolling force setup model, improve the crudy of strip.

Summary of the invention

Problem to be solved by this invention provides a kind of finite element revised law of non-oriented electrical steel resistance of deformation, it has revised the calculated value of non-oriented electrical steel resistance of deformation, improve the default precision of roll-force, thereby guaranteed the quality of production of non-oriented electrical steel.

A kind of CSP production line non-oriented electrical steel resistance of deformation finite element revised law of the present invention, this method includes the following step:

1) the roll-force data of collection actual detected;

2) the roll-force data of actual detected are brought into SIMS unit's roll-force formula and release the resistance of deformation initial value;

SIMS unit's roll-force formula wherein is

$\frac{P}{B\sqrt{R(h_0-h)}}=(\frac{p}{2}\sqrt{\frac{1-h_{\mathrm{eps}}}{h_{\mathrm{eps}}}}\arctan \sqrt{\frac{h_{\mathrm{eps}}}{1-h_{\mathrm{eps}}}}-\frac{p}{4}-\sqrt{\frac{1-h_{\mathrm{eps}}}{h_{\mathrm{eps}}}}\sqrt{\frac{R}{h}}\ln \frac{h_r}{h}+\frac{1}{2}\sqrt{\frac{1-h_{\mathrm{eps}}}{h_{\mathrm{eps}}}}\sqrt{\frac{R}{h}}\ln \frac{1}{1-h_{\mathrm{eps}}})K$

Wherein, $h_{\mathrm{eps}}=\frac{h_0-h}{h_0}$

h _r＝h+Rr ²

$r=\sqrt{\frac{h}{R}}\tan \frac{1}{2}\arctan \sqrt{\frac{h_{\mathrm{eps}}}{1-h_{\mathrm{eps}}}}+\frac{p}{8}\sqrt{\frac{h}{R}}\ln (1-h_{\mathrm{eps}})$

In the above-mentioned formula, P is a general rolling force; B is a strip width; R is the working roll radius; h ₀Be inlet thickness; H is an exit thickness; h _EpsBe relative reduction; h _rBe the neutral angle respective heights; K is a resistance of deformation; R is a neutral angle.

3) the resistance of deformation initial value is revised:

1. adopt the method for 3D solid finite element modelling, roll shifting amount and geometric parameters such as bending roller force and roll diameter of roller actual in the resistance of deformation initial value of needs correction, the production process are brought into the FEM model analog computation, draw the strip crown value, because of having only resistance of deformation in the analog computation is parameter, so can obtain the linear relation of resistance of deformation and strip crown;

2. the method by iteration in 5%, is finished the correction of resistance of deformation with the strip crown that guarantees analog computation and go out and the strip crown error of producing each frame of setting.

The method of CSP production line non-oriented electrical steel resistance of deformation finite element revised law of the present invention is that theoretical calculating of resistance of deformation and finite element modelling correction are combined, consider to influence numerous factors of resistance of deformation simultaneously, CSP is produced the resistance of deformation of non-oriented electrical steel and carried out dynamic studies, obtain the theoretical calcuating correction value of resistance of deformation.

The invention has the beneficial effects as follows: 1, since the inventive method in FEM model with on-the-spot actual production technological parameter as input value, so the closing to reality production environment can truly reflect the situation of change of resistance of deformation in each frame of tandem rolling; 2, this method has been used FEM model correction resistance of deformation, has done effective trial on this difficult problem of Changing Pattern that solves the multi-pass deformation drag, can optimize the level two deformation resistance model; 3, optimize the rolling force setup value with corrected resistance of deformation value, improve the default precision of roll-force, guarantee that the operation of rolling is stable, improves product quality.

The FEM model of the foundation in the inventive method can be studied different operating modes, and extends to the resistance of deformation correction of similar milling train different cultivars steel, has actual using value.

Description of drawings:

Fig. 1 is a FEM model modeling flow chart of the present invention;

Fig. 2 is a 3D solid FEM model of the present invention;

Fig. 3 is a calculation flow chart of the present invention;

Fig. 4 is a CSP production line MGW1300 resistance of deformation curve map.

The specific embodiment

A kind of CSP production line non-oriented electrical steel resistance of deformation finite element revised law of the present invention, this method includes the following step: the roll-force data of 1) gathering actual detected; 2) the roll-force data of actual detected are brought into SIMS unit's roll-force formula and release the resistance of deformation initial value; 3) the resistance of deformation initial value is revised: the method that 1. adopts the 3D solid finite element modelling, roll shifting amount and geometric parameters such as bending roller force and roll diameter of roller actual in the resistance of deformation initial value of needs correction, the production process are brought into the FEM model analog computation, draw the strip crown value, because of having only resistance of deformation in the analog computation is parameter, so can obtain the linear relation of resistance of deformation and strip crown; 2. the method by iteration in 5%, is finished the correction of resistance of deformation with the strip crown that guarantees analog computation and go out and the strip crown error of producing each frame of setting.

Wherein, the roll-force of the SIMS unit described in the step 2 formula is

$\frac{P}{B\sqrt{R(h_0-h)}}=(\frac{p}{2}\sqrt{\frac{1-h_{\mathrm{eps}}}{h_{\mathrm{eps}}}}\arctan \sqrt{\frac{h_{\mathrm{eps}}}{1-h_{\mathrm{eps}}}}-\frac{p}{4}-\sqrt{\frac{1-h_{\mathrm{eps}}}{h_{\mathrm{eps}}}}\sqrt{\frac{R}{h}}\ln \frac{h_r}{h}+\frac{1}{2}\sqrt{\frac{1-h_{\mathrm{eps}}}{h_{\mathrm{eps}}}}\sqrt{\frac{R}{h}}\ln \frac{1}{1-h_{\mathrm{eps}}})K$

Wherein, $h_{\mathrm{eps}}=\frac{h_0-h}{h_0}$

h _r＝h+Rr ²

$r=\sqrt{\frac{h}{R}}\tan \frac{1}{2}\arctan \sqrt{\frac{h_{\mathrm{eps}}}{1-h_{\mathrm{eps}}}}+\frac{p}{8}\sqrt{\frac{h}{R}}\ln (1-h_{\mathrm{eps}})$

In the above-mentioned formula, P is a general rolling force; B is a strip width; R is the working roll radius; h ₀Be inlet thickness; H is an exit thickness; h _EpsBe relative reduction; h _rBe the neutral angle respective heights; K is a resistance of deformation; R is a neutral angle.

The modeling procedure of the FEM model of step 3-described in 1. is: 1) definition model geometric parameter, material properties, cell type, the resistance of deformation of being released by SIMS unit's roll-force formula; 2) definition CVC roller curve coefficient; 3) set up key point,, generate face by line again, generate body by the face rotation at last, finish the modeling process of cell cube by the dot generation line; 4) grid is divided; 5) the definition working roll contacts with the band steel with backing roll, working roll, the definition boundary condition; 6) load bending roller force at working roll roll neck place, slide by front and back with band steel contact position at working roll and load roll-force respectively; 7) find the solution; 8) the strip crown value after post processing obtains finding the solution.Because the precision of FEM model is the key to the correction of resistance of deformation initial calculation value, divide carefullyyer so modeling procedure 4 grids are divided in working roll and backing roll contact position and band steel and working roll contact position, divide a grid every 20mm.

The method of the iteration of step 3-described in 2. is: 1) when the strip crown of finite element simulation calculation with when producing the strip crown error set＜5%, accept this resistance of deformation; 2) when the strip crown of finite element simulation calculation with when producing the strip crown error set 〉=5%, then calculate new resistance of deformation in the linear relation of resistance of deformation that 1. substitution of strip crown change value is obtained by step 3-and strip crown, 1. carrying out strip crown again according to step 3-then calculates, when strip crown error＜5%, accept this resistance of deformation; If strip crown error 〉=5%, 1. repeating step 3-finishes up to strip crown error＜5% again.Resistance of deformation that 1. step 3-obtains and strip crown linear relation are:

VC=0.032*VK is wherein: VC is a strip crown change value; VK is a resistance of deformation change value.

Wherein, strip crown change value is poor for the strip crown of the strip crown set and analog computation.When choosing the strip crown value of setting, taken all factors into consideration the factor of each side, through actual measurement, the setting value that the strip convexity meets the demands is as choosing condition in will producing.

Be that embodiment does further detailed introduction to the present invention with the MGW1300 non-oriented electrical steel below.

According to method step of the present invention, gather the actual detected roll-force data of seven frames of F1-F7 earlier, it and the geometric parameter substitution SIMS unit roll-force formula of roller system, rolled piece are calculated the resistance of deformation initial value, then the relevant parameter in the production process is brought in the FEM model, and can draw corrected MGW1300 resistance of deformation value by the method for iteration, concrete data see Table 1.

Table 1 MGW1300 resistance of deformation corrected Calculation

Shelf number	??F1	??F2	??F3	??F4	??F5	??F6	??F7
								Deformation temperature/℃	??1001	??984	??968	??960	??933	??907	??883
Actual detected roll-force/kN	??31543	??31458	??27522	??21223	??16376	??14239	??9885
								Resistance of deformation initial value/MPa	??153.51	??160.08	??210.19	??264.58	??308.33	??298.61	??297.8
Bending roller force/kN	??1310	??1310	??1260	??1242	??970	??959	??327
								Roll shifting amount/mm	??100	??93	??16	??20	??58	??45	??68
Set strip crown/um	??138.8	??127.5	??117.4	??49.2	??60.3	??30.9	??22.7
								Resistance of deformation correction value/MPa	??153.51	??160.08	??210.19	??273.31	??318.33	??290.55	??289.98

Seven corrected resistance of deformation relation curves of frame of F1-F7 drafting pattern 4.

As can be seen from Figure 4, F1-F5 stand stretch drag increases progressively, and the F3-F4 frame is through after the preceding two passages distortion, and resistance of deformation increases remarkable, and this is that strain rate increases because temperature reduces, and work hardening has certain accumulation, and softening insufficient event.In the F5 frame, when inlet temperature was 933 ℃, resistance of deformation reached maximum 318.33.In the F6 frame, resistance of deformation reduces, and F7 stand stretch drag is almost suitable with F6, this be the accumulation of work hardening and produce dynamic recrystallization softening due to.By seven stand stretch drags are analyzed, for the stable control of MGW1300 non-oriented electrical steel production process provides theoretical foundation.

Claims (5)

1. CSP production line non-oriented electrical steel resistance of deformation finite element revised law, this method includes the following step:

1) the roll-force data of collection actual detected;

2) the roll-force data of actual detected are brought into SIMS unit's roll-force formula and release the resistance of deformation initial value;

SIMS unit's roll-force formula is:

$\frac{P}{B\sqrt{R(h_0-h)}}=(\frac{p}{2}\sqrt{\frac{1-h_{\mathrm{eps}}}{h_{\mathrm{eps}}}}\arctan \sqrt{\frac{h_{\mathrm{eps}}}{1-h_{\mathrm{eps}}}}-\frac{p}{4}-\sqrt{\frac{1-h_{\mathrm{eps}}}{h_{\mathrm{eps}}}}\sqrt{\frac{R}{h}}\ln \frac{h_r}{h}+\frac{1}{2}\sqrt{\frac{1-h_{\mathrm{eps}}}{h_{\mathrm{eps}}}}\sqrt{\frac{R}{h}}\ln \frac{1}{1-h_{\mathrm{eps}}})K$

Wherein, $h_{\mathrm{eps}}=\frac{h_0-h}{h_0}$

hr＝h+Rr ²

$r=\sqrt{\frac{h}{R}}\tan \frac{1}{2}\arctan \sqrt{\frac{h_{\mathrm{eps}}}{1-h_{\mathrm{eps}}}}+\frac{p}{8}\sqrt{\frac{h}{R}}\ln (1-h_{\mathrm{eps}})$

In the above-mentioned formula, P is a general rolling force; B is a strip width; R is the working roll radius; h ₀Be inlet thickness; H is an exit thickness; h _EpsBe relative reduction; h _rBe the neutral angle respective heights; K is a resistance of deformation; R is a neutral angle.

3) the resistance of deformation initial value is revised:

1. adopt the method for 3D solid finite element modelling, roll shifting amount and geometric parameters such as bending roller force and roll diameter of roller actual in the resistance of deformation initial value of needs correction, the production process are brought into the FEM model analog computation, draw the strip crown value, because of having only resistance of deformation in the analog computation is parameter, so can obtain the linear relation of resistance of deformation and strip crown;

2. the method by iteration in 5%, is finished the correction of resistance of deformation with the strip crown that guarantees analog computation and go out and the strip crown error of producing each frame of setting.

2. a kind of CSP production line non-oriented electrical steel resistance of deformation finite element revised law according to claim 1 is characterized in that: the modeling procedure of the FEM model of step 3-described in 1. is:

1) definition model geometric parameter, material properties, cell type are by the resistance of deformation of SIMS unit's roll-force formula release;

2) definition CVC roller curve coefficient;

3) set up key point,, generate face by line again, generate body by the face rotation at last, finish the modeling process of cell cube by the dot generation line;

4) grid is divided;

5) the definition working roll contacts with the band steel with backing roll, working roll, the definition boundary condition;

6) load bending roller force at working roll roll neck place, slide by front and back with band steel contact position at working roll and load roll-force respectively;

7) find the solution;

8) the strip crown value after post processing obtains finding the solution.

3. a kind of CSP production line non-oriented electrical steel resistance of deformation finite element revised law according to claim 2 is characterized in that: the grid of the modeling procedure 4 of the FEM model of step 3-described in is 1. divided and is meant in working roll and backing roll contact position and a grid is divided every 20mm in band steel and working roll contact position.

4. a kind of CSP production line non-oriented electrical steel resistance of deformation finite element revised law according to claim 1 is characterized in that: the method for the iteration of step 3-described in 2. is:

1) when the strip crown of finite element simulation calculation with when producing the strip crown error set＜5%, accepts this resistance of deformation;

2) when the strip crown of finite element simulation calculation with when producing the strip crown error set 〉=5%, then calculate new resistance of deformation in the linear relation of resistance of deformation that 1. substitution of strip crown change value is obtained by step 3-and strip crown, 1. carrying out strip crown again according to step 3-then calculates, when strip crown error＜5%, accept this resistance of deformation; If strip crown error 〉=5%, 1. repeating step 3-finishes up to strip crown error＜5% again.

5. a kind of CSP production line non-oriented electrical steel resistance of deformation finite element revised law according to claim 1, it is characterized in that: the resistance of deformation that 1. step 3-obtains and the linear relation of strip crown are:

VC＝0.032*VK

Wherein: VC is a strip crown change value; VK is a resistance of deformation change value.

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