CN114289522A

CN114289522A - Optimization method of Sendzimir twenty-high rolling mill roll system rolling process parameters based on orthogonal test

Info

Publication number: CN114289522A
Application number: CN202111566864.6A
Authority: CN
Inventors: 王辉; 秦晓峰; 徐锟; 谢晶; 张青
Original assignee: Baosteel Roll Science & Technology Co ltd
Current assignee: Baosteel Roll Science & Technology Co ltd
Priority date: 2021-12-20
Filing date: 2021-12-20
Publication date: 2022-04-08

Abstract

The invention discloses a method for optimizing rolling process parameters of a Sendzimir twenty-high rolling mill roll system based on an orthogonal test, which comprises the following steps of: designing influence factors and test levels of the influence factors; the influence factors are the convexity of the two intermediate rolls, the taper length of the one intermediate roll and the transverse displacement of the one intermediate roll; the test level of the convexity of the two intermediate rolls is 5, the test level of the taper length of the one intermediate roll is 8, and the test level of the transverse displacement of the one intermediate roll is 6; establishing an orthogonal test table according to the designed influence factors and the test level thereof to perform an orthogonal test of the maximum contact stress of the working roll and the plate; and thirdly, performing range analysis and variance analysis according to the orthogonal test result to obtain optimized rolling process parameters of the roll system. The optimization method provided by the invention can reduce the contact stress between the rollers on the basis of ensuring the quality of the plate, further reduce the consumption of the rollers, has important significance, and has the advantages of small test amount and high optimization efficiency compared with the traditional comprehensive test method and the like.

Description

Optimization method of Sendzimir twenty-high rolling mill roll system rolling process parameters based on orthogonal test

Technical Field

The invention belongs to the technical field of Sendzimir twenty-high roll mills, and particularly relates to an optimization method of Sendzimir twenty-high roll mill roll system rolling process parameters based on an orthogonal test.

Background

The Sendzimir twenty-high roll mill is a representative product for precision rolling, and the rolling process parameters determine the rolling efficiency and quality in the production process. The research on the influence of the rolling process parameters on the contact stress between the rollers has important significance for controlling the geometric precision, the plate shape and the surface quality of a rolled piece, prolonging the service life of the rollers and the like.

The Sendzimir twenty-high roll mill roll system is divided into an upper group and a lower group, and each group consists of 1 working roll, 2 first intermediate rolls, 3 second intermediate rolls and 4 supporting rolls.

At present, the optimization of the rolling process parameters of the Sendzimir twenty-high roll mill at home and abroad is difficult to reflect the important degree of the maximum contact stress between the rolls by the common rolling process parameters, and has great limitation. Therefore, a method for optimizing the rolling process parameters of the Sendzimir twenty-high roll mill roll system is urgently needed in the field.

Disclosure of Invention

The invention aims to solve the problems and provides a method for optimizing rolling process parameters of a Sendzimir twenty-high rolling mill roll system based on an orthogonal test.

The technical scheme for realizing the purpose of the invention is as follows: a method for optimizing rolling process parameters of a Sendzimir twenty-high rolling mill roll system based on an orthogonal test comprises the following steps: designing influence factors and test levels of the influence factors; the influence factors are the convexity of the two intermediate rolls, the taper length of the one intermediate roll and the transverse displacement of the one intermediate roll; the test level of the convexity of the two intermediate rolls is 5, the test level of the taper length of the one intermediate roll is 8, and the test level of the transverse displacement of the one intermediate roll is 6; establishing an orthogonal test table according to the influence factors and the test level thereof designed in the step I, and carrying out an orthogonal test on the maximum contact stress of the working roll and the plate; and thirdly, performing range analysis and variance analysis according to the orthogonal test result of the step II to obtain optimized rolling process parameters of the roll system.

In the first step, the 5 test levels of the convexity of the two intermediate rolls are respectively 0mm, 0.05mm, 0.1mm, 0.2mm and 0.3 mm; the 8 test levels of an intermediate roll taper length include 4 two-segment taper lengths 255mm, 300mm, 375mm, 425mm and 4 parabolic taper lengths P255mm, P300mm, P375mm, P425 mm; the 6 test levels of the transverse displacement of the middle roller are respectively 0mm, 20mm, 40mm, 60mm, 80mm and 100 mm.

In the second step, the number of the orthogonal tests is 48.

In the third step, the optimized rolling process parameters of the roller system are as follows: the convexity of the two intermediate rolls is 0.1-0.2 mm, the taper length of one intermediate roll is 425mm of the taper length of the two intermediate rolls or the taper length of a parabola P425mm, and the transverse displacement of one intermediate roll is 0 mm.

In the third step, the optimized rolling process parameters of the roller system are as follows: the crown of the two intermediate rolls was 0.2mm, the taper length of one intermediate roll was parabolic taper length P425mm, and the cross-travel of one intermediate roll was 0 mm.

The invention has the following positive effects:

(1) the optimization method of the invention designs an orthogonal test scheme, combines rolling process parameters, plans test levels of different influence parameters on the basis of analyzing and determining key influence parameters and the influence rule of the key influence parameters on the contact stress distribution, calculates the contact stress distribution under different influence parameter levels by combining a numerical method, then carries out data processing through an orthogonal test, obtains the influence trend and the influence degree of the maximum contact stress between the rollers by each influence factor based on range and variance analysis, and further finds the rolling process parameter combination with the minimum maximum contact stress peak value.

(2) The optimization method provided by the invention can reduce the contact stress between the rollers on the basis of ensuring the quality of the plate, further reduce the consumption of the rollers, has important significance, and has the advantages of small test amount and high optimization efficiency compared with the traditional comprehensive test method and the like.

Drawings

FIG. 1 is a graph of maximum contact stress between a work roll and a sheet material as a function of crown of two intermediate rolls.

FIG. 2 is a graph of maximum contact stress of the work roll and sheet material as a function of taper length of an intermediate roll.

FIG. 3 is a graph showing the maximum contact stress between the work rolls and the sheet material as a function of the amount of lateral movement of an intermediate roll.

Detailed Description

(example 1)

The optimization method of the rolling process parameters of the Sendzimir twenty high rolling mill roll system based on the orthogonal test comprises the following steps:

designing influence factors and test levels of the influence factors.

Wherein: the influence factors are 3, which are two intermediate roll crown (factor 1), one intermediate roll taper length (factor 2) and one intermediate roll lateral shift amount (factor 3).

Wherein, the convexity of the two middle rollers can be used for adjusting the edge thinning phenomenon, and the contact stress between the rollers has important influence. The convexity of the two middle rollers is provided with 5 test levels which are respectively 0mm, 0.05mm, 0.1mm, 0.2mm and 0.3 mm.

An intermediate roll taper length was set at 8 test levels, including 4 two-step taper lengths 255mm, 300mm, 375mm, 425mm and 4 parabolic taper lengths P255mm, P300mm, P375mm, P425 mm.

Wherein: the 4 parameters of the taper length of the two sections are designed in a table 1, and the 4 parameters of the taper length of the parabola are designed in a table 2.

TABLE 1

Two-stage taper length/mm	L1/mm	H1/mm	L2/mm	H2/mm
					255	180	0.09	75	0.27
300	200	0.09	100	0.35
					375	300	0.1	75	0.57
425	350	0.07	75	0.67

TABLE 2

Parabolic taper length/mm	Formula of conicity
		P255
P300
		P375
P425

The transverse displacement of the middle roller has important influence on the shape of the plate; when the taper length is constant, the ability of an intermediate roll to inhibit the edge portions of the sheet from thinning can be enhanced by increasing the amount of cross-travel. A middle roller transverse displacement is provided with 6 test levels which are respectively 0mm, 20mm, 40mm, 60mm, 80mm and 100 mm.

And secondly, establishing an orthogonal test table (see table 3) according to the influence factors designed in the step I and the test levels thereof, and performing 48 groups of orthogonal tests on the maximum contact stress of the working roll and the plate, wherein the results are also shown in table 3.

TABLE 3

Numbering	Factor 1	Factor 2	Factor 3	Convexity/mm of two intermediate rolls	A taper length/mm of intermediate roll	A transverse displacement/mm of the intermediate roll	Maximum contact stress/MPa
								1	1	1	1	0	255	0	5319.08
2	2	2	1	0.05	300	0	5142.05
								3	3	3	1	0.1	375	0	4068.77
4	4	4	1	0.2	425	0	3675.45
								5	5	5	1	0.3	P255	0	5158.92
6	5	5	2	0.3	P300	20	5116.32
								7	4	6	2	0.2	P375	20	4506.22
8	3	7	2	0.1	P425	20	3692.03
								9	2	8	3	0.05	P425	40	5086.84
10	1	7	3	0	P375	40	4819.54
								11	1	6	4	0	P300	60	5251.30
12	2	5	2	0.05	P255	20	5289.43
								13	3	4	3	0.1	425	40	5078.50
14	4	1	3	0.2	255	40	5262.15
								15	5	2	3	0.3	300	40	5158.27
16	5	3	4	0.3	375	60	4941.40
								17	4	3	5	0.2	375	80	5082.59
18	3	2	4	0.1	300	60	5209.47
								19	2	6	5	0.05	P300	80	5193.09
20	1	4	2	0	425	20	3845.50
								21	1	5	5	0	P255	80	5140.04
22	2	1	4	0.05	255	60	5272.11
								23	3	7	5	0.1	P375	80	4954.97
24	4	8	4	0.2	P425	60	4150.51
								25	5	8	5	0.3	P425	80	5735.99
26	5	7	6	0.3	P375	100	4935.12
								27	4	5	6	0.2	P255	100	5073.99
28	3	6	6	0.1	P300	100	5066.33
								29	2	4	6	0.05	425	100	4933.02
30	1	3	6	0	375	100	5200.12
								31	1	2	6	0	300	100	5244.54
32	2	3	2	0.05	375	20	4556.67
								33	3	1	2	0.1	255	20	5245.73
34	4	2	2	0.2	300	20	5184.82
								35	5	1	6	0.3	255	100	5067.57
36	5	4	5	0.3	425	80	4642.96
								37	4	6	3	0.2	P300	40	5192.95
38	3	5	3	0.1	P255	40	5207.53
								39	2	7	4	0.05	P375	60	4951.16
40	1	8	6	0	P425	100	4818.52
								41	1	8	1	0	P425	0	3667.99
42	1	7	1	0	P375	0	4115.88
								43	1	5	4	0	P255	60	5203.21
44	1	6	1	0	P300	0	5154.42
								45	1	4	4	0	425	60	4373.47
46	1	1	5	0	255	80	5270.00
								47	1	2	5	0	300	80	5300.57
48	1	3	3	0	375	40	4859.39
								K1	4848.97	5239.44	4537.82
K2	5053.04625	5206.62	4679.59
								K3	4815.41625	4784.823	5083.14625
K4	4766.085	4424.8167	4919.079
								K5	5094.56875	5178.853	5165.026
K6		5162.402	5042.40125
								K7		4713.815
K8		4525.313
								R	328.484	814.623	627.206
S	1039874.62	4618801.29	2432429.66

And thirdly, performing range analysis and variance analysis according to the orthogonal test result obtained in the step two, wherein the results are respectively shown in a table 3 and a table 4.

TABLE 4

Sources of variance	Sum of squared deviations (SS)	Degree of Freedom (DF)	Mean Square (MS)	F value	Optimized value
						Convexity of two intermediate rolls	1039874.62	4	259968.655	0.166	0.2mm
A length of taper of the intermediate roll	4618801.29	7	659828.756	0.4213	P425mm
						A transverse displacement of the intermediate roll	2432429.66	5	486485.932	0.31	0mm
Error of the measurement	3132241.85	2	1566120.925
						Sum of	9213452.57	18

The larger the range R and variance F values are, the greater the influence of the influencing factor on the result. As can be seen from tables 2 and 3: the effect of the taper length of one intermediate roll on the maximum contact stress of the working roll and the sheet is the greatest, and the effect of the crown of the two intermediate rolls is the least, which is probably because one intermediate roll only affects the contact stress by passing through the working roll, and the two intermediate rolls can affect the contact stress of the working roll and the sheet by passing through one intermediate roll and the working roll.

The maximum contact stress between the working roll and the sheet material is shown in the graph of fig. 1 to 3 along with the change of the convexity of two intermediate rolls, the taper length of one intermediate roll and the transverse displacement of one intermediate roll.

As can be seen from fig. 1: the maximum contact stress between the working roll and the plate is firstly increased, then reduced and then increased along with the increase of the convexity of the two middle rolls.

As can be seen from fig. 2: the maximum contact stress of the work rolls with the sheet material decreases as the taper length of an intermediate roll increases. Wherein: parabolic tapers generally have lower maximum contact stresses than two-step tapers because the parabolic taper makes an intermediate roll taper transition smoother and more stress concentration-reducing.

As can be seen from fig. 3: the maximum contact stress of the working roll and the plate is firstly increased along with the increase of the transverse displacement of an intermediate roll and then tends to be stable, wherein: the maximum contact stress variation of the amount of the traverse between 0mm and 20mm is very small.

Claims

1. A method for optimizing rolling process parameters of a Sendzimir twenty-high rolling mill roll system based on an orthogonal test is characterized by comprising the following steps:

designing influence factors and test levels of the influence factors;

the influence factors are the convexity of the two intermediate rolls, the taper length of the one intermediate roll and the transverse displacement of the one intermediate roll; the test level of the convexity of the two intermediate rolls is 5, the test level of the taper length of the one intermediate roll is 8, and the test level of the transverse displacement of the one intermediate roll is 6;

establishing an orthogonal test table according to the influence factors and the test level thereof designed in the step I, and carrying out an orthogonal test on the maximum contact stress of the working roll and the plate;

and thirdly, performing range analysis and variance analysis according to the orthogonal test result of the step II to obtain optimized rolling process parameters of the roll system.

2. The optimization method of the rolling process parameters of the Sendzimir twenty high roll mill based on the orthogonal test as claimed in claim 1, characterized in that: in the first step, the 5 test levels of the convexity of the two intermediate rolls are respectively 0mm, 0.05mm, 0.1mm, 0.2mm and 0.3 mm; the 8 test levels of an intermediate roll taper length include 4 two-segment taper lengths 255mm, 300mm, 375mm, 425mm and 4 parabolic taper lengths P255mm, P300mm, P375mm, P425 mm; the 6 test levels of the transverse displacement of the middle roller are respectively 0mm, 20mm, 40mm, 60mm, 80mm and 100 mm.

3. The optimization method of the rolling process parameters of the Sendzimir twenty high roll mill based on the orthogonal test as claimed in claim 1, characterized in that: in the second step, the number of the orthogonal tests is 48.

4. The optimization method of the rolling process parameters of the Sendzimir twenty high roll mill rolling train based on orthogonal tests according to one of claims 1 to 3, characterized in that: in the third step, the optimized rolling process parameters of the roller system are as follows: the convexity of the two intermediate rolls is 0.1-0.2 mm, the taper length of one intermediate roll is 425mm of the taper length of the two intermediate rolls or the taper length of a parabola P425mm, and the transverse displacement of one intermediate roll is 0 mm.

5. The optimization method of the Sendzimir twenty high roll mill rolling process parameters based on the orthogonal test as claimed in claim 4, characterized in that: in the third step, the optimized rolling process parameters of the roller system are as follows: the crown of the two intermediate rolls was 0.2mm, the taper length of one intermediate roll was parabolic taper length P425mm, and the cross-travel of one intermediate roll was 0 mm.