CN100475369C - 6mm steel plate rolling technique - Google Patents

Abstract

The invention provides a rolling technique for rolling a steel plate of 6mm by using a middle-thickness rolling mill which carries out corresponding settlements on the furnace discharge temperature of a stock, the stock thickness, rolling gates, an automatic gauge control, a rolling force, the self-adaptation coefficients of the rolling force between the gates, an opposite convexity and the matching between the linear speed of a transmission roller gate and the linear speed of the working roller of a rolling mill. The technique solves the problems of waves, bending, camber, frame scraping and waste rolling appearing in the plank stuffs during the testing rolling of 6mm plates of the existing middle-thickness rolling mill, leads the rolling to be stable and can manufacture qualified products in batch.

Description

A kind of 6mm steel plate rolling technique

Technical field

The present invention relates to the metallurgical industry plate rolling process, the rolling mill practice of the rolling 6mm steel plate of particularly a kind of heavy and medium plate mill.

Background technology

The steel plate of 6mm is generally rolling by continuous hot-rolling mill, steekle mill now, but the steel plate width＜1800mm that rolls out, and can only produce common steel grade, can not satisfy the demand in market.For producing the 6mm steel plate of width greater than 1800mm, people attempt coming rolling with heavy and medium plate mill.The specification of institute's rolled plate is the wide 600-3800mm of plate, thickness 6-200mm in the heavy and medium plate mill design.But, in actual production, understand emersion wave shape wave, camber, scrape frame, roll problems such as useless with the rolling steel plate of heavy and medium plate mill less than 7mm, produce instability especially, can not form mass production capabilities.It is stable that main cause is that thin wide steel plate rolling state is difficult for, and temperature drop is very fast, roll shape, rolling condition are required very high, when the high-speed rolling sheet metal, the hydraulic AGC system instability, conventional model precision of prediction deviation is big.

Summary of the invention

The objective of the invention is to, at existing heavy and medium plate mill in rolling existing problems and can not form mass production capabilities during less than the 7mm steel plate, and the rolling mill practice of the rolling 6mm steel plate of a kind of heavy and medium plate mill is proposed, when it can effectively solve the rolling 6mm steel plate of existing heavy and medium plate mill existing such as: rolling instability, waveform, camber, scrape frame, roll problems such as useless, but the qualified product of output and form mass production capabilities.

Can realize purpose of the present invention by following technical proposals, the rolling mill practice of the rolling 6mm steel plate of a kind of heavy and medium plate mill is characterized in that:

1, the tapping temperature of blank 〉=1200 ℃, finishing temperature＞740 ℃;

2, sotck thinkness≤250mm rolls back hair plates width≤2800mm, length≤50m.

3, rolling pass is made as the 11-13 passage.

4, before the open rolling Target Board, milling train should possess the continuous rolling time more than 30 minutes, made work roll thermal crown stable; Before the open rolling Target Board, should press the sheet material of rolling other specification of 10-15 piece of order from thick to thin earlier, and last at least 4 thickness≤10mm, make the model adaptation coefficient progressively approach the as-rolled condition of 6mm plate.

5, optimize hydraulic AGC (automatic thickness control, as follows) gain, guarantee the AGC system stability, regulate the AGC gain in the operation of rolling automatically, when rolled piece thickness 〉=10mm, the AGC gain is fixed as 90%; Behind rolled piece thickness＜10mm, the AGC gain is successively decreased automatically by the linear function that just is cut to 0.1; Behind rolled piece thickness≤6mm, the AGC gain is fixed as 50%.Can avoid AGC system oscillation.

6, last 3 passages adopt equal proportion convex degree control method control panel shape, roll-force descends by the road, final pass rolling force setup value is 0.32-0.38 a times of milling train maximum rolling force, and the roll-force adaptation coefficient is made as 0.35-0.45 between passage, and the ratio convexity is set between 0.7%～1.5%.

7, rollgang linear velocity and operation roll of mill linear velocity coupling, last 3 road outlet side rollgang linear velocities are than the fast 3-5% of operation roll of mill linear velocity, and entrance side rollgang speed can avoid steel plate to pile up than the slow 3--5% of operation roll of mill linear velocity.

8, the working roll of just having changed can not roll the 6mm Target Board immediately, and rolling time should just can rolling Target Board greater than 4 hours.

9, rolling pass is made as 11 passages during sotck thinkness＜150mm, and during sotck thinkness 〉=150mm, rolling pass is made as 13 passages;

10, adopt rational roll shape system.Backing roll adopts positive roll shape, and hyperbola form, convexity are 0.2mm,

Effect of the present invention is: owing to taked above-mentioned effective measures, in the operation of rolling of 6mm Target Board, rolling stable, rolled piece does not have wave, the song that wafts, camber, scrape frame, roll problems such as useless; Rolled piece can be rolling smoothly, and in the end 3 passages guarantee rolled piece ratio convexity between 0.7%～1.5%, and it is laterally mobile to have avoided rolled piece to take place in milling train, and at ± 0.1mm, different plate difference can mass-produce qualified products at ± 0.15mm to Target Board with the plate difference.

Below in conjunction with embodiment the present invention is further set forth:

The specific embodiment

Embodiment 1: earlier with the time more than 30 minutes, rolling 13 its thickness are the steel plate between the 20-7mm, and to thin arrangement, the thickness of last 4 block plates is followed successively by 10,9,8,7mm by thick.Blanket thickness is 120mmm, and rolling pass is made as 11 passages.Backing roll used 10 days, and working roll used 13 hours.The AGC gain setting: during rolled piece thickness 〉=10mm is 90%, and rolled piece thickness≤6mm is 50%, and rolled piece thickness is between 10mm～6mm, and the AGC gain is successively decreased automatically by the linear function that just is cut to 0.1, and this can be avoided AGC system oscillation.The final pass rolling force setup is 0.33 times of milling train maximum rolling force.Last 3 passage adaptation coefficients 0.39, the ratio convexity is set at 0.8%.Last 3 passage outlet side rollgang linear velocities are faster 3.5% than operation roll of mill linear velocity, and entrance side rollgang speed is than operation roll of mill linear velocity slow 3.5%.Rolled piece, roll and rolling technological parameter are seen tabulation (the rolling parameter measured value is the measurement mean value of 1/4 length in the middle of the rolled piece):

(1) 6mm plate rolling model parameter (elongation rolling sequence)

Parameter name	Numerical value	Explanation
			TYPESTRAT	3	The control of equal proportion convexity is adopted in 3 expressions, to guarantee plate shape
MAXFORCELAST	2500kN	Final pass maximum rolling force (be milling train maximum rolling force 0.33 times)
			TORQUENOMINAL	5000KN.m	Maximum moment
MAXTORQUE	0.80	The moment safety coefficient
			ADARATEFP	0.39	Roll-force adaptation coefficient between passage
MINREDREL	0.03	Minimum reduction ratio
			MINREDRELLAST	0.03	The minimum reduction ratio of final pass
MINREDRELLAST1	0.11	The minimum reduction ratio in road second from the bottom
			MINREDRELLAST2	0.12	The minimum reduction ratio in road third from the bottom
VMIN	2m/s	Minimum speed
			VMAX	4.5m/s	Maximal rate
VENDLAST	3.5m/s	Final pass speed

(2) rolled piece parameter

Raw material specification

120x2000x2480mm

Steel grade	BVA
		Roll back hair plates specification	6.2x2755x34800mm
Tapping temperature	1209℃

(3) roll data

Roll	Material	Diameter, mm	Convexity, μ m	Rolled plate cumulative length, km	Rolled plate weight, ton
						Top backing up roll	AST60	1987.65	200	241.78	25956
The lower support roller	AST60	1995.80	200	241.78	25956
						Top working roll	NiCr	1018.05	0	21.62	1534
Bottom working roll	NiCr	1018.15	0	21.62	1534

(4) calculate rules and rolling parameter

Passage	Exit thickness, mm	The actual measurement roll gap, mm	The actual measurement roll-force, kN	Calculate roll-force, kN	Actual measurement moment, kNm	Factored moment .kNm	The actual measurement outlet temperature, ℃	Rolling time, s	Off time, s
										1	102.79	100.21	14188	14510	1417	1616	1130	1.1	0
2	87.29	84.13	15953	15441	1601	1634	1099	1.5	16.3
										3	62.52	56.92	30300	28614	3633	3796	1080	1.8	19.4
4	42.03	35.73	32709	32681	3620	3807	1072	2.7	12.0
										5	26.37	18.98	38874	37428	3336	3784	1069	3.3	8.3
6	16.01	8.65	37440	42119	2519	3384	1047	4.8	8.3
										7	10.78	3.40	36807	38811	1692	2291	1014	5.7	5.6
8	8.56	1.85	31416	30096	929	1197	944	5.5	9.5
										9	7.29	1.10	27337	27181	578	785	881	7.2	7.0
10	6.50	0.82	23619	23996	387	495	818	7.9	6.0
										11	6.17	1.16	18816	17398	229	221	741	10.2	7.0

Roll back hair plates width and answer≤2800mm, otherwise plate shape is difficult to control.If the working roll just changed can not roll the 6mm Target Board immediately, rolling time should just can rolling Target Board greater than 4 hours.

Embodiment 2: earlier with the time more than 30 minutes, rolling 13 its thickness are the steel plate between the 20-7mm, and to thin arrangement, the thickness of last 4 block plates is followed successively by 10,9,8,7mm by thick.Blanket thickness is 210mmm, and rolling pass is made as 13 passages.Backing roll used 3 days, and working roll used 15 hours.The AGC gain setting: during rolled piece thickness 〉=10mm is 90%, and rolled piece thickness≤6mm is 50%, and rolled piece thickness is between 10mm～6mm, and the AGC gain is successively decreased automatically by the linear function that just is cut to 0.1, and this can be avoided AGC system oscillation.The final pass rolling force setup is 0.38 times of milling train maximum rolling force.Last 3 passage adaptation coefficients 0.35, the ratio convexity is set at 1.0%.Last 3 passage outlet side rollgang linear velocities are faster 5% than operation roll of mill linear velocity, and entrance side rollgang speed is than operation roll of mill linear velocity slow 5%.Backing roll adopts positive roll shape, and hyperbola form, convexity are 0.2mm, and working roll carries out the transition to 0.2mm according to backing roll length service time convexity by 0mm.Rolled piece, roll and rolling technological parameter are seen tabulation (the rolling parameter measured value is the measurement mean value of 1/4 length in the middle of the rolled piece):

(1) 6mm plate rolling model parameter (elongation rolling sequence)

(2) rolled piece parameter

Raw material specification	210mmx1400mmx2470mm
		Steel grade	Q345B
Roll back hair plates specification	6.1mmx2500mmx47618mm
		Tapping temperature	1218℃

(3) roll data

Roll	Material	Diameter, mm	Convexity, μ m	Rolled plate cumulative length, km	Rolled plate weight, ton
						Top backing up roll	AST60	1990.90	200	96.85	8726
The lower support roller	AST60	1991.20	200	96.85	8726
						Top working roll	NiCr	976.50	100	26.08	2112
Bottom working roll	NiCr	977.30	100	26.08	2112

(4) calculate rules and rolling parameter

Passage

Exit thickness, mm

The actual measurement roll gap, mm

The actual measurement roll-force, kN

Calculate roll-force, kN

Actual measurement moment, kNm

Factored moment, kNm

The actual measurement outlet temperature, ℃

Rolling time, s

Off time, s

1	176.41	174.48	19110	19129	3365	2736	1114	1	0
										2	144.93	142.39	19563	19702	2957	2407		1	9
3	115.77	112.55	20820	21111	3246	2579	1189	2	9
										4	89.10	85.16	22932	23828	2980	2930	1136	2	22
5	61.81	56.75	27415	30588	3760	3797	1187	2	8
										6	39.85	33.84	31710	33965	3437	3868	1169	4	9
7	23.57	16.63	36660	40111	3371	3899	1230	6	7
										8	15.79	9.41	31682	31980	1834	2225	1151	6	8
9	11.78	5.35	31202	27728	1266	1411	1158	6	14
										10	9.26	2.32	34357	28922	1077	1125	1016	7	8
11	7.70	1.25	30585	29499	721	874	972	9	7
										12	6.67	0.11	31047	29947	573	695	871	13	7
13	6.14	-0.45	31087	27654	426	472	755	14	7

Sotck thinkness should≤250mm, roll back hair plates length should≤50m, otherwise the road number of times is too many, finishing temperature does not guarantee that steel plate longitudinal temperature difference causes with the plate difference big too greatly, plate shape is also very poor.

Claims (3)

1, the rolling mill practice of the rolling 6mm steel plate of a kind of heavy and medium plate mill is characterized in that:

(1), tapping temperature 〉=1200 of blank ℃, finishing temperature＞740 ℃;

(2), sotck thinkness≤250mm, roll back hair plates width≤2800mm, length≤50m;

(3), rolling pass is made as the 11-13 passage;

(4), before the open rolling Target Board, milling train should possess the continuous rolling time more than 30 minutes, made work roll thermal crown stable; Before the open rolling Target Board, should press the sheet material of rolling other specification of 10-15 piece of order from thick to thin earlier, and last at least 4 thickness≤10mm, make the model adaptation coefficient progressively approach the as-rolled condition of 6mm plate;

(5), regulate the AGC gain in the operation of rolling automatically, when rolled piece thickness 〉=10mm, the AGC gain is fixed as 90%; Behind rolled piece thickness＜10mm, the AGC gain is successively decreased automatically by the linear function that just is cut to 0.1; Behind rolled piece thickness≤6mm, the AGC gain is fixed as 50%, can avoid AGC system oscillation;

(6), last 3 passages adopt equal proportion convex degree control method control panel shape, roll-force descends by the road, final pass rolling force setup value is 0.32-0.38 a times of milling train maximum rolling force, and the roll-force adaptation coefficient is made as 0.35-0.45 between passage, and the ratio convexity is set between 0.7%～1.5%;

(7), rollgang linear velocity and operation roll of mill linear velocity coupling, last 3 road outlet side rollgang linear velocities are than the fast 3-5% of operation roll of mill linear velocity, entrance side rollgang speed can avoid steel plate to pile up than the slow 3-5% of operation roll of mill linear velocity.

By the rolling mill practice of the rolling 6mm steel plate of the described heavy and medium plate mill of claim 1, it is characterized in that 2, rolling pass is made as 11 passages during sotck thinkness＜150mm, during sotck thinkness 150mm-250mm, rolling pass is made as 13 passages.

3, by the rolling mill practice of claim 1 or the rolling 6mm steel plate of 2 described heavy and medium plate mills, it is characterized in that backing roll adopts positive roll shape, hyperbola form, convexity are 0.2mm.