阅读说明：本技术 一种工作辊窜辊行程和窜辊步长双衰减的异步窜辊方法 (Asynchronous roll shifting method with double attenuation of roll shifting stroke and roll shifting step length of working roll ) 是由 何安瑞 齐志 姚驰寰 李辉 周冠禹 刘超 郭蓝田 于 2021-08-30 设计创作，主要内容包括：本发明公开了一种工作辊窜辊行程和窜辊步长双衰减的异步窜辊方法,包括确定下游机架从窜辊零位到窜辊极限位置所需的窜动步数、下游机架初始窜辊行程、末期窜辊行程、下游第i机架初始窜辊位置距离窜辊零位的异步块数和下游i机架窜辊行程开始衰减时所轧制板带块数n,预设下游机架轧制最后一块板带块数,计算出第i机架当前窜辊行程,计算所轧制板带与异步块数之和在当前周期T内各机架窜辊步数,计算下游第i机架工作辊轧制第n块板带时的窜辊位置。异步窜辊方法避免板带长期和轧辊同一区域接触导致局部磨损过大,提高工作辊磨损均匀性,多机架异步避开了窜辊零位时多个机架轧辊“猫耳”磨损箱体对板带压延效果的相互叠加,提高板带板形质量。(The invention discloses an asynchronous roll shifting method with double attenuation of a roll shifting stroke and a roll shifting step length of a working roll, which comprises the steps of determining the number of shifting steps required by a downstream rack from a roll shifting zero position to a roll shifting limit position, the initial roll shifting stroke and the final roll shifting stroke of the downstream rack, the number of asynchronous blocks of the initial roll shifting position of an ith downstream rack from the roll shifting zero position and the number of rolled strips n when the roll shifting stroke of the ith downstream rack starts to attenuate, presetting the number of the last strips rolled by the downstream rack, calculating the current roll shifting stroke of the ith rack, calculating the sum of the rolled strips and the number of the asynchronous blocks, calculating the roll shifting steps of each rack in the current period T, and calculating the roll shifting position when the working roll of the ith downstream rack rolls the nth strip. The asynchronous roll shifting method avoids overlarge local abrasion caused by long-term contact of the plate strip and the same area of the roll, improves the abrasion uniformity of the working roll, and improves the plate shape quality of the plate strip by mutually overlapping the rolling effect of a plurality of rack roll 'cat ear' abrasion box bodies on the plate strip when the multi-rack asynchronous avoids roll shifting zero position.)

1. The asynchronous roll shifting method for double attenuation of roll shifting stroke and roll shifting step length of the working roll is characterized by comprising the following steps of:

s100, determining the required shifting step number q of a downstream rack from a zero position of shifting rollers to a limit position of shifting rollers;

s200, determining the initial roll shifting stroke L of the downstream frame_sEnd stage roll shifting stroke L_e；

S300, determining the number m of asynchronous blocks between the initial roll shifting position of the ith downstream rack and the zero position of the roll shifting_iI is 1,2, …, N, where N is the number of downstream racks;

s400, determining the number of rolled plate strips to be n when the roll shifting stroke of the ith downstream rack starts to attenuate_si；

S500, presetting the number n of the last plate strip rolled by the downstream frame_e；

S600, enabling the number of the current rolled plate strips to be n after rolling is started, wherein n is 1,2 and 3; judging n-1 and n_siThe size relationship of (1) is calculated by using a piecewise function when n-1 is less than n_siAnd n-1 is not less than n_siCurrent roll shifting stroke L of the ith frame_i；

S700, recording the roll shifting period T from the roll shifting zero position to the roll shifting zero position again, wherein T is 4q, and calculating the roll shifting step number of each rack in the current period T as n of the sum of the rolled strip and the number of asynchronous blocks_Ti；

S800, in the current period T, calculating the current n by using a piecewise function_Ti≤q、q＜n_TiLess than or equal to 3q and n_TiRoll shifting position S when the ith downstream rack working roll rolls the nth plate strip when the speed is higher than 3q_i(n)。

2. The asynchronous roll shifting method based on double attenuation of the roll shifting stroke and the roll shifting step length of the working roll according to claim 1, characterized in that in step S200, an initial roll shifting stroke Ls and a final roll shifting stroke Le of a downstream frame are determined according to the width of a plate strip and the actual working condition in the field.

3. The asynchronous roll shifting method based on double attenuation of roll shifting stroke and roll shifting step length of working rolls as claimed in claim 1, wherein in step S300, the initial roll shifting positions of the working rolls of the downstream stands are different when rolling the strip, and m is different₁≠m₂≠....≠m_N。

4. The work roll shifting stroke and shifting step double attenuation asynchronous roll shifting method according to claim 1, characterized in that in step S600;

when n-1 < n_siCurrent roll shifting stroke L of ith frame_i＝L_s；

When n-1 is more than or equal to n_siCurrent roll shifting stroke of ith frame

5. The work roll shifting stroke and shifting step double attenuation asynchronous roll shifting method according to claim 1, characterized in that in step S700;

according to formula n_Ti＝(n-1+m_i) % calculation (4 × q) n_TiThe value of (c).

6. The work roll shifting stroke and shifting step double attenuation asynchronous roll shifting method according to claim 1, characterized in that in step S800;

when n is_TiWhen the ratio of q is less than or equal to q,

when q is less than n_TiWhen the content is less than or equal to 3q,

when n is_TiWhen the carbon content is larger than 3q,

Technical Field

The invention relates to the technical field of hot rolling roll shifting control, in particular to an asynchronous roll shifting method with double attenuation of roll shifting stroke and roll shifting step length of a working roll.

Background

And the working roll moves transversely to form the working roll shifting. According to different roll shape curve forms, the roll shape curves can be divided into conventional convexity roll shape curves (such as parabola and sine curves) and continuous convexity roll shape curves (such as CVC and LVC). The roll shifting of the conventional crowned roll shape aims to uniformize the abrasion of the working roll and improve the cross-sectional shape of the rolled strip. The roll shifting mode is three types:

the first is a constant-stroke and constant-step roll shifting mode, so that roll shifting stroke and roll shifting step length are kept fixed to carry out periodic reciprocating roll shifting, the roll shifting mode improves box type abrasion and 'cat ears' when roll shifting is not carried out, but after abrasion is aggravated in the middle and later periods of rolling, when the roll shifting reaches the stroke limit, an abrasion groove slope enters the edge part of a plate strip to be too long, and convexity and edge waves can be increased.

The second is a roll shifting mode with the roll shifting stroke being periodically attenuated and the step length being unchanged, and a representative document is 'hot rolling work roll variable stroke roll shifting strategy' (university of Beijing university of science 2011,33 (01)). The detailed research and analysis of the strategy are carried out, and the roll shifting mode can increase the abrasion width of the working roll and reduce the abrasion height of a cat ear. The roll shifting strategy has the problem that the roll shifting position of the working roll is more repeated or approximately repeated in the whole rolling cycle. If the roll shifting position of the roll is repeated, the local abrasion of the working roll is increased, and the abrasion homogenization of the roll is not facilitated.

The third is the roll shifting mode with roll shifting stroke attenuation and variable step length. Representative documents are: the patent of a variable-stroke and variable-step-length roll shifting method (publication number: CN105598182A) applies the variable-stroke and variable-step-length roll shifting method to solve the problem of plate shape defects caused by local abrasion of a working roll and avoid the repetition of roll shifting positions. However, the roll shifting of the working rolls of the downstream frames can reach the roll shifting zero point and the roll shifting limit position at the same time, and the roll shifting of the rolls is not staggered asynchronously, so that the positions of the rolls of each downstream frame, which are seriously worn, are overlapped, and the plate strip is easy to generate local high points when the roll shifting is shifted to the zero point in the later rolling period. In the patent of an asynchronous roll shifting control method for working rolls of hot continuous rolling downstream racks (publication number: CN107824617B), the three downstream racks are respectively subjected to positive and negative phase shifts on the basis of the same sine roll shifting function, so that the three racks form asynchronous roll shifting, and the adverse effect of mutual superposition of multiple rack roll shifting zero positions in the whole roll shifting period is avoided. However, the sine roller shifting has the defects that the roller shifting step length is small at the roller shifting limit position, the retention time is long, the number of rolled plate strips is large, the roller shifting step length is large near the roller shifting zero position, the retention time is short, the number of rolled plate strips is small, the retention time of the roller at the roller shifting limit position is long, the rolling stability is influenced, and the plate strip convexity quality fluctuation is easily caused when the roller returns from the roller limit position.

In summary, the roll shifting method cannot give consideration to the homogenization of the plate shape quality of the plate strip and the abrasion of the roll in the rolling process.

Disclosure of Invention

The invention provides an asynchronous roll shifting method with double attenuation of roll shifting stroke and roll shifting step length of a working roll.

To solve the above technical problem, an embodiment of the present invention provides the following solutions:

the embodiment of the invention provides an asynchronous roll shifting method for double attenuation of roll shifting stroke and roll shifting step length of a working roll, which comprises the following steps:

s100, determining the required shifting step number q of a downstream rack from a zero position of shifting rollers to a limit position of shifting rollers;

s200, determining the initial roll shifting stroke L of the downstream frame_sEnd stage roll shifting stroke L_e；

S300, determining the initial roller position of the ith downstream frameNumber m of asynchronous blocks at zero position of distance shifting roller_iI is 1,2, …, N, where N is the number of downstream racks;

s400, determining the number of rolled plate strips to be n when the roll shifting stroke of the ith downstream rack starts to attenuate_si；

S500, presetting the number n of the last plate strip rolled by the downstream frame_e；

S600, enabling the number of the current rolled plate and strip blocks after rolling is started to be n, wherein n is 1,2 and 3 …; judging n-1 and n_siThe size relationship of (1) is calculated by using a piecewise function<n_siAnd n-1 is not less than n_siCurrent roll shifting stroke L of the ith frame_i；

S700, recording the roll shifting period T from the roll shifting zero position to the roll shifting zero position again, wherein T is 4q, and calculating the roll shifting step number of each rack in the current period T as n of the sum of the rolled strip and the number of asynchronous blocks_Ti；

S800, in the current period T, calculating the current n by using a piecewise function_Ti≤q、q<n_TiLess than or equal to 3q and n_Ti>Roll shifting position S when the downstream ith frame working roll rolls the nth plate strip at 3q_i(n)。

Preferably, in step S200, an initial roll shifting stroke Ls and a final roll shifting stroke Le of the downstream frame are determined according to the strip width and the actual working condition on site.

Preferably, in step S300, the initial roll shifting position when the downstream stand work rolls roll the strip is different, m₁≠m₂≠…≠m_N。

Preferably, in step S600;

when n-1<n_siCurrent roll shifting stroke L of ith frame_i＝L_s；

When n-1 is more than or equal to n_siCurrent roll shifting stroke of ith frame

Preferably, in step S700;

according to formula n_Ti＝(n-1+m_i) % calculation (4 × q) n_TiA value of (d);

preferably, in step S800;

when n is_TiWhen the ratio of q is less than or equal to q,

when q is<n_TiWhen the content is less than or equal to 3q,

when n is_Ti>At the time of 3q, the compound (b),

the scheme of the invention at least comprises the following beneficial effects:

in the scheme, the asynchronous roll shifting method avoids mutual superposition of the calendering effects of the cat ear abrasion box bodies of the plurality of stand rolls on the plate strip when the roll shifting is in the zero position, reduces the convexity of an abrasion roll gap, and is beneficial to the overall stability of a product control index; the method has the advantages that the repetition of the roller shifting position of the roller in the rolling period is avoided, meanwhile, the influence of excessive stay of the roller at the roller shifting limit position on the plate shape quality of the plate strip is also avoided, the roller abrasion uniformity is obviously improved, the box type abrasion is improved, the roller changing period is prolonged, and the problem of excessive local abrasion caused by long-term contact of the same area of the roller with the plate strip is effectively avoided.

Drawings

FIG. 1 is a flow chart of a work roll shifting stroke and shifting step length dual attenuation asynchronous roll shifting method of the present invention;

FIG. 2 is a graph of the variation of downstream three-stand roll shifting stroke and roll shifting step length double-attenuation asynchronous roll shifting with the number of rolling blocks provided by the embodiment of the invention;

FIG. 3 is a comparison diagram of the strip cross section situation at the later stage of rolling in a downstream three-stand roll shifting process and a roll shifting step length double-attenuation asynchronous roll shifting method and an equal-stroke equal-step roll shifting method provided by the embodiment of the invention;

FIG. 4 is a graph comparing abrasion loss of a working roll in a downstream three-stand roll shifting stroke and roll shifting step double-attenuation asynchronous roll shifting method and an equal-stroke equal-step roll shifting method F4 provided by the embodiment of the invention;

FIG. 5 is a graph comparing abrasion loss of a working roll in a downstream three-stand roll shifting stroke and roll shifting step double-attenuation asynchronous roll shifting method and an equal-stroke equal-step roll shifting method F5 provided by the embodiment of the invention;

FIG. 6 is a graph comparing abrasion loss of a working roll in a downstream three-frame roll shifting stroke and roll shifting step double-attenuation asynchronous roll shifting method and an equal-stroke equal-step roll shifting method F6 provided by the embodiment of the invention.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

As shown in FIG. 1, the embodiment of the invention provides an asynchronous roll shifting method with double attenuation of roll shifting stroke and roll shifting step length of a working roll, which is suitable for a hot rolling downstream machine frame. The asynchronous roll shifting method comprises the following steps:

s100, determining the required shifting step number q of a downstream rack from a zero position of shifting rollers to a limit position of shifting rollers;

s200, determining the initial roll shifting stroke L of the downstream frame_sEnd stage roll shifting stroke L_e；

S300, determining the number m of asynchronous blocks between the initial roll shifting position of the ith downstream rack and the zero position of the roll shifting_iI is 1,2, …, N, where N is the number of downstream racks;

s400, determining the number of rolled plate strips to be n when the roll shifting stroke of the ith downstream rack starts to attenuate_si；

S500, presetting the number n of the last plate strip rolled by the downstream frame_e；

S600, enabling the number of the current rolled plate and strip blocks after rolling is started to be n, wherein n is 1,2 and 3 …; judging n-1 and n_siThe size relationship of (1) is calculated by using a piecewise function<n_siAnd n-1 is not less than n_siWhen the ith rack isFront shifting roller stroke L_i；

S700, recording the roll shifting period T from the roll shifting zero position to the roll shifting zero position again, wherein T is 4q, and calculating the roll shifting step number of each rack in the current period T as n of the sum of the rolled strip and the number of asynchronous blocks_Ti；

S800, in the current period T, calculating the current n by using a piecewise function_Ti≤q、q<n_TiLess than or equal to 3q and n_Ti>Roll shifting position S when the downstream ith frame working roll rolls the nth plate strip at 3q_i(n)。

The asynchronous roll shifting method avoids mutual superposition of the rolling effect of the plate strip by a plurality of rack roll 'cat ear' abrasion box bodies when the roll shifting is in a zero position, reduces the convexity of an abrasion roll gap, and is beneficial to the overall stability of a product control index; the method has the advantages that the repetition of the roller shifting position of the roller in the rolling period is avoided, meanwhile, the influence of excessive stay of the roller at the roller shifting limit position on the plate shape quality of the plate strip is also avoided, the roller abrasion uniformity is obviously improved, the box type abrasion is improved, the roller changing period is prolonged, and the problem of excessive local abrasion caused by long-term contact of the same area of the roller with the plate strip is effectively avoided.

In step S200, an initial roll shifting stroke Ls and a final roll shifting stroke Le of the downstream frame are determined according to the width of the plate strip and the actual working condition on site.

In step S300, the initial roll shifting positions of the working rolls of the downstream stands are different when rolling the strip, and m is₁≠m₂≠…≠m_NThe problem that the rollers of all the machine frames at the downstream reach the roller shifting limit position at the same time is solved;

in step S600;

when n-1<n_siCurrent roll shifting stroke L of ith frame_i＝L_s；

When n-1 is more than or equal to n_siCurrent roll shifting stroke of ith frame

In step S700;

according to formula n_Ti＝(n-1+m_i) % calculation (4 × q) n_TiA value of (d);

in step S800;

when n is_TiWhen the ratio of q is less than or equal to q,

when q is<n_TiWhen the content is less than or equal to 3q,

when n is_Ti>At the time of 3q, the compound (b),

the asynchronous roll shifting method with double attenuation of roll shifting stroke and roll shifting step length of the working roll provided by the embodiment is applied to three downstream stands of a certain hot continuous rolling production line, and the asynchronous roll shifting method is specifically as follows:

s100, determining the required shifting step number q of the downstream frame from the zero position of the shifting roller to the limit position of the shifting roller to be 6;

s200, determining the initial roller shifting stroke L of a downstream rack according to the width of a plate strip and the actual working condition on site_s90mm and a final roll shifting stroke L_e＝50mm；

S300, determining the number m of asynchronous blocks between the initial roll shifting position of the ith downstream rack and the zero position of the roll shifting_iAnd i is 1,2, …, and N, wherein N is 3, and the number of the downstream racks is the number of the downstream racks. m is₁＝3，m₂＝0，m₃The initial roll shifting positions of the working rolls of the downstream frames when rolling the plate strip are different from each other-3, so that the problem that the rolls of the downstream frames simultaneously reach the roll shifting limit positions is solved;

s400, determining the number of rolled plate strips to be n when the roll shifting stroke of the ith downstream rack starts to attenuate_si，n_s1＝27，n_s2＝30，n_s3＝33；

S500, presetting the number n of the last plate strip rolled by the downstream frame_e＝100；

S600, the number of the currently rolled strip pieces after the start of rolling is set to n-29. Judging n-1 and n_siThe size of (2). When n-1<n_siI.e. downstream 2 nd rack is 29-1<30, downstream No. 3 rack is 29-1<33, the current roll shifting stroke of the downstream 2 nd and 3 rd frames is as follows:

L₂＝L₃＝L_s＝90

when n-1 is more than or equal to n_siNamely, the downstream No. 1 frame is 29-1 to 27, and the current roll shifting stroke of the downstream No. 1 frame is as follows:

s700, returning from the zero position of roll shifting to the zero position of roll shifting again is recorded as a roll shifting period T being 4q being 4 x 6 being 24, and the sum of the rolled strip and the number of asynchronous blocks is the roll shifting step number n in the current period T_Ti＝(n-1+m_i)％(4×q)；

n_T1＝(29-1+3)％(4×6)＝7，n_T2＝4，n_T3＝1；

S800, calculating the roll shifting position S of the working rolls of the downstream frames when the 29 th plate strip is rolled in the current period T-24_i(n), judging n_TiThe size of (a) is (b),

when q is<n_T1When the ratio is 7-3 q,

when n is_T2When q is not less than 4,

when n is_T3When q is not greater than 1, the reaction solution,

the roll shifting positions of the strip in one rolling unit for the different downstream stands F4, F5 and F6 work rolls are shown in fig. 2; FIG. 3 is a comparison of the cross-section situation of the asynchronous roll shifting method of the embodiment with the equal-stroke equal-step roll shifting method in the prior art at the later stage of rolling when rolling the same specification plate strip, and it can be seen from FIG. 3 that the plate strip thickness is significantly smaller than that of the equal-stroke equal-step roll shifting method in the prior art; as can be seen from fig. 4 to 6, the cat ear of the work roll wear profile is reduced by applying the asynchronous roll shifting method of the present embodiment, the axial wear of the roll is more uniform, the roll wear uniformity is significantly improved, the wear roll gap convexity is reduced, and the overall stability of the product control index is facilitated. The method has the advantages that the repetition of the roller shifting position of the roller in the rolling period is avoided, meanwhile, the influence of excessive stay of the roller at the roller shifting limit position on the plate shape quality of the plate strip is avoided, the box type abrasion is improved, the roller changing period is prolonged, and the problem of excessive local abrasion caused by long-term contact of the same area of the roller with the plate strip is effectively avoided.

While the foregoing is directed to the preferred embodiment of the present invention, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims.