CN101722188B - Method for cold rolling of austenite stainless steel plate strip - Google Patents

Abstract

The invention relates to a method for the cold rolling of an austenite stainless steel plate strip. The stainless steel plate strip comprises the following components in percentage by mass: 0.10 percent of C, 1.00 percent of Si, 1.50 percent of Mn, 0.030 percent of P, 0.015 percent of S, 30 to 35 percent of Ni, 19 to 23 percent of Cr, 0.75 percent of Cu, 0.15 to 0.60 percent of Al, 0.15 to 0.60 percent of Ti and the balance of iron and inevitable impurities. Feeding and discharge thicknesses and front and rear tensile force values at each pass in cold rolling rules are calculated according to a formula in a cold rolling technical process. The cold rolling method can reduce the friction coefficient on the contact surface of a cold rolling deformation area of the steel strip, thereby reducing cold rolling pressure, improving cold rolling production efficiency and making the elongation of the rolled piece easy.

Description

A kind of cold rolling process of austenite stainless steel plate strip

Technical field

The present invention relates to a kind of milling method of stainless steel plate strip, particularly relate to a kind of cold rolling process of austenite stainless steel plate strip.

Background technology

Along with domestic and international development of science and technology; The stainless steel industry new product emerges in an endless stream; New steel grade constantly emerges; Nowadays 800 series have obtained the approval to this series of plates band of the same trade under the wideling popularize on border made the country prosperous in credit, because of 800 series of plates bands have good corrosion-resistant, high radiation, anti-oxidant and outstanding welding performance, so this series stainless steel strip material is widely applied on the senior electrothermal tube of 927 ℃ of high temperature uses.800 series of plates bands are environmental protection strip material simultaneously, so be widely applied on the high-end products such as space shuttle, marine ship.800 series stainless steels are a kind of novel austenite stainless steel plate strips, can be widely used in heat-generating pipe, heat exchanger, petrochemical industry, generating equipment heater, industrial oven in order, acids manufacturing equipment, fields such as beach facility.

Because 800 series stainless steels belong to acidproof, heat-resisting a kind of novel stainless steel, that work-hardening capacity is gathered way is faster than ferritic stainless steel because the part austenite structure changes martensitic structure into when cold working, makes the hardenability aggravation; But this series stainless steel is owing to there are anti-oxidant, the heat-resisting and good advantages such as weldability ability of superiority to be approved by a lot of field; Because of stainless steel plate strip direct-furnish ratio height on market; And the cold-rolling process of 800 series stainless steels that is that all right at home is ripe; Therefore, be necessary very much this novel austenite stainless steel is formulated new cold-rolling process.

Summary of the invention

The objective of the invention is to; Overcome the defective of the rolling mill practice existence of existing stainless steel plate strip; And a kind of cold rolling process of new austenite stainless steel plate strip is provided; Make its sassafras series number that rubs that guarantees to reduce cold roller and deformed district contact surface, thereby reduce cold rolling pressure and cold rolling rate consumption, make rolled piece be easy to extend.

The present invention proposes a kind of cold rolling process of austenite stainless steel plate strip, this stainless steel plate strip contains following chemical composition, by percentage to the quality, and C:0.10; Si:1.00, Mn:1.50, P:0.030, S:0.015; Ni:30～35, Cr:19～23, Cu:0.75; Al:0.15～0.60, Ti:0.15～0.60, surplus is that iron and unavoidable impurities are formed; In the cold-rolling process step, calculate pan feeding, discharging thickness in the cold rolling rolling schedule, H: pan feeding thickness by following formula; H; Discharging thickness; H ₀: raw thickness, absolute draft amount Δ h=H-h; Pass reduction ε=Δ h/H * 100%; Total working modulus before the passage ${\mathrm{\ϵ}}_H=\frac{H_0-H}{H}\×100\%;$ Total working modulus after the passage ${\mathrm{\ϵ}}_h=\frac{H_0-h}{H}\×100\%;$ The average working modulus ε of passage=0.4 ε _H+ 0.6 ε _h

In the cold-rolling process step, calculate the forward and backward tension value of passage in the cold rolling rolling schedule, q by following formula _HBe expressed as the preceding unit tension of strip of steel plate; q _hBe expressed as the back unit tension of strip of steel plate; It is wide that B is expressed as the plate of strip of steel plate.

Passage forward pull Q _H=q _H* B * _HPassage backward pull Qh=q h * B * h; Mean tension Q=(Q _h+ Q _H)/2.

In addition, the invention allows for a kind of cold rolling process of austenite stainless steel plate strip, this stainless steel plate strip contains following chemical composition, by percentage to the quality; C:0.08, Si:0.40～0.80, Mn:0.20～0.70, P:0.025; S:0.015, Ni:18～22, Cr:18～22; Al:0.20～0.60, Ti:0.20～0.60, surplus is that iron and unavoidable impurities are formed; In the cold-rolling process step, calculate pan feeding, discharging thickness in the cold rolling rolling schedule, H: pan feeding thickness by following formula; H; Discharging thickness; H0: raw thickness, absolute draft amount Δ h=H-h; q _HBe expressed as the preceding unit tension of strip of steel plate; q _hBe expressed as the back unit tension of strip of steel plate; It is wide that B is expressed as the plate of strip of steel plate.

Pass reduction ε=Δ h/H * 100%; Total working modulus before the passage ${\mathrm{\ϵ}}_H=\frac{H_0-H}{H}\×100\%;$

Total working modulus after the passage ${\mathrm{\ϵ}}_h=\frac{H_0-h}{H}\×100\%;$ The average working modulus ε of passage=0.4 ε _H+ 0.6 ε _h

In the cold-rolling process step, calculate the forward and backward tension value of passage in the cold rolling rolling schedule by following formula,

Passage forward pull Q _H=q _H* B * _HPassage backward pull Qh=qh * B * h; Mean tension Q=(Q _h+ Q _H)/2.

By technique scheme; The advantage that the cold rolling process of austenite stainless steel plate strip of the present invention has is: cold-rolling process of the present invention can guarantee to reduce the sassafras series number that rubs of cold roller and deformed district contact surface; Thereby reduce cold rolling pressure and improve cold rolling production efficiency, make rolled piece be easy to extend; The cold-rolled strip that obtains through cold-rolling process of the present invention has good mechanical performance, and it can be widely applied on the high-end products such as space shuttle, marine ship.

Description of drawings

Fig. 1 is the roll dangerouse cross-section force diagram of the used four-high mill in the cold-rolling process of the present invention.

The specific embodiment

Cold-rolling process of the present invention can briefly be expressed as: to the cold deformation degree of 800 series stainless steel strip materials; The Distribution Calculation of drafts and technological lubrication; Problems such as technology cooling are further studied, and at first rule of thumb carry out the distribution of drafts, secondly want art with reference to empirical documentation by technology; Choose each passage unit tension; At last the processing procedure of drafting is carried out the check (load) of equipment and the regulation of restrictive condition, and suitably revise, finally sum up the cold rolling rules of 800 series of plates bands according to actual production.

Wherein, the needed computing formula of cold rolling rolling schedule, as follows:

See cold rolling rolling schedule table, the relevant calculation explanation is an example with 1060 as follows in will showing at present.Wherein, the q in the 11st～13 _hBe expressed as the unit tension of strip of steel plate; It is wide that B is expressed as the plate of strip of steel plate.

The 1st～2: H and h are by the plasticity decision of Product Status and mill capacity and alloy.

H: inlet thickness; H; Exit thickness; H ₀: raw thickness.

The 3rd～8: the 3rd, absolute draft amount Δ h=H-h

The 4th, pass reduction ε=Δ h/H * 100%

The 5th, total working modulus before the passage ${\mathrm{\ϵ}}_H=\frac{H_0-H}{H}\×100\%$

The 6th, total working modulus after the passage ${\mathrm{\ϵ}}_h=\frac{H_0-h}{H}\×100\%$

The 7th, the average working modulus ε of passage=0.4 ε _H+ 0.6 ε _h

The 8th～10: the 8th is rolled preceding metal yield limit σ _SHCan table look-up;

The 9th is rolled back metal yield limit σ _ShCan table look-up;

The 10th, ${\stackrel{\‾}{\mathrm{\σ}}}_s=\frac{1}{3}{\mathrm{\σ}}_{\mathrm{SH}}+\frac{2}{3}\mathrm{Sh}.$

The 11st～13: passage forward pull Q _H=q _H* B * _H

Passage backward pull Q _h=q _h* B * h

Mean tension Q=(Q _h+ Q _H)/2

The 14th～15: the 14th average deformation drag k=1.15 σ _s

Consider that tension force influences k '=1.15 σ for the 15th _s-σ.

The 16th～18: the 16th roll before length L 1 roll before length decide by the ingot casting or the back length of rolling that goes up a time;

The 17th is rolled back length L 2 and rolls the back length L ₂, have according to the constancy of volume principle $L_2=\frac{B_1\×H\×L_1}{h\×B_2}$ Try to achieve, wherein B ₁=B ₂

The 18th mill speed V.

The 19th～20: the 19th rolling time $t_1=\frac{L_2}{V};$

Get t the 20th non-cutting time ₂=5s.

The 21st: coefficient of friction, get f=0.15.

The 22nd: the contact arc floor projection $L=\sqrt{R\×\mathrm{\Δ\; h}}$ Wherein R is a work roll diameter, gets 325mm.

The 23rd～24: the 23rd m=2fL/ (H+h), wherein $L=\sqrt{R\·\mathrm{\Δ\; h}};$

The 24th y=4afk '/(H+h), a=R/9500 wherein,

The 25th m ' be by m, y, can table look-up.

The 26th～27: the 26th roll elastic flattening arc floor projection L '=m ' * (H+h)/(2 * m);

The 27th parameter=δ=2 * f * L '/(H+h).

The 28th: pressure system ${\mathrm{\η}}_{\mathrm{\σ}}^{\′}=\stackrel{\‾}{p}/k^{\′}=0.785+0.25\·\sqrt{R\·\mathrm{\Δ\; h}}/\stackrel{\‾}{h};$

The 29th: average unit pressure P '=n ' σ K '.

The 30th～31: the 30th rolled piece mean breadth is that the width B after the hot rolling deducts the side cut amount.

The 31st parameter contact area floor projection F=B * L.

The 32nd: roll-force P=P ' F.

The 33rd: the angle of action

The 34th～35: the 34th forward pull Q _h=q _hF;

The 35th backward pull Q _H=q _HF.

The 36th: roll torque $M_Z=2\×\stackrel{\‾}{P^{\′}}\·d\·\sqrt{R\·\mathrm{\Δ\; h}}/1000,\mathrm{KN}\·m.$

The 37th: the coefficient of friction f in the bearing ₁=0.003.

The 38th: moment of friction $M_f=\frac{M_{f_1}}{\mathrm{I\η}}+(\frac{1}{\mathrm{\η}}-1)M_Z.$

The 39th～41: the 39th motor maximum (top) speed n Get 1200r/min;

The 41st speed reducing ratio i is i=2.1;

The 40th roll rotational speed does $n=\frac{60\·V}{\mathrm{\π}\·D}.$

The 42nd～43: the 42nd idling torque M ₀, get M by empirical equation ₀=0.06M _Z

The 43rd statical moment $M_c=\frac{M_z}{i}+M_f+M_0.$

The 44th～47: the 44th is the resultant couple of each section rolling time, ∑ M _C ²T ₁

The 45th is the idling torque sum of intermittent time, ∑ M _0n ^{/ 2}T ₂

The 46th is the rolling time summation;

The 47th is the intermittent time summation.

The 48th: equivalent moment $\stackrel{\‾}{M}=\sqrt{\frac{\mathrm{\Σ}{M}_c^2\·t_n+\mathrm{\Σ}{M_o}^2{t}_n^{\′}}{\mathrm{\Σ}{t}_n+\mathrm{\Σ}{t}_n^{\′}}};$

Wherein: ∑ t _n---the summation S of each section rolling time in the rolling cycle;

∑ t ' _n---each intersegmental crack temporal summation S in the rolling cycle;

M _c---the resultant couple that each section rolling time is corresponding, Nm

M ' _o---the idle running resultant couple that each intersegmental crack time is corresponding, Nm

The 49th: calculate power of motor, press $N=\frac{1.03\stackrel{\‾}{M}\·n}{\mathrm{\η}}\mathrm{KW}.$

Wherein: M---rolling pass equivalent moment, Nm;

N---roll revolution, 100r/min;

η---by the transmission efficiency of motor, get 0.87 to milling train.

The 50th: select power of motor.

Cold-rolling process is checked, as follows:

Bite condition is checked: press Δ h max≤D (1-cos β)

Coefficient of friction f gets 0.08, then tg β=f=0.08 β=4.57 °

cosβ＝0.997。Δh _max＝D(1-cosβ)＝650(1-0.997)＝1.95mm

Under the cold rolling in the technological procedure table each reduction in pass all be less than 1.95mm, bite condition satisfies.

Strength check: the four-high mill of working roll main transmission, working roll receives moment of torsion, and backing roll receives moment of flexure, and the moment of torsion of evaluation work roller, the moment of flexure of backing roll are checked intensity by result of calculation, and be as shown in Figure 1.

Be example with austenite stainless steel plate NAS800, the NAS840 of 500mm thickness respectively below, specify pan feeding, the discharging thickness of passage in the cold rolling rolling schedule, and forward and backward tension value.

Embodiment 1

Steel grade: NAS800L, by percentage to the quality,

C:0.10, Si:1.00, Mn:1.50, P:0.030, S:0.015, Ni:30～35, Cr:19～23, Cu:0.75, Al:0.15～0.60, Ti:0.15～0.60, surplus is that iron and unavoidable impurities are formed;

According to the computing formula of above-mentioned cold rolling rolling schedule, can draw table 1:

Table 1NAS800L 3.5mm---0.43mm (500mm)

Passage	Pan feeding thickness mm	Discharging thickness mm	Forward pull (T)	Backward pull (T)
					1	3.5	2.7	21.3	6
2	2.7	2.18	21.3	12
					3	2.18	1.76	21.3	12
4	1.76	1.42	21.3	12
					5	1.42	1.15	21.3	12
6	1.15	0.94	13	11
					7	0.94	0.77	10	9
8	0.77	0.63	7.5	7
					9	0.63	0.52	7	6.5
10	0.52	0.43	6.5	6.3

Wherein, in cold-rolling process, the 1-2 passage is used the NO.1 working roll; The 3-4 passage is used the NO.1 working roll; The 5-6 passage is used the NO.2 working roll; The 7-8 passage is used the NO.2 working roll; 9 passages are used the NO.2 working roll; 10 passages are used the 2B working roll.In cold rolling back during two passages, pay special attention to check whether defectiveness of surface of steel plate, when cold rolling last passage, earlier about cold rolling 3～5 circles, stop and survey whether defectiveness of steel plate thickness and inspection surface of steel plate.If working roll causes defective must in time change (skid like working roll and cause serious aberration, defectives such as roller point) during production.Must standard check surface quality when cold rolling.Mechanical performance through the strip of steel plate behind the above-mentioned cold-rolling process is as shown in table 2 below:

The mechanical performance of table 2NAS800L

Embodiment 2

Steel grade: NASH840, by percentage to the quality,

C:0.08, Si:0.40～0.80, Mn:0.20～0.70, P:0.025, S:0.015, Ni:18～22, Cr:18～22, Al:0.20～0.60, Ti:0.20～0.60, surplus is that iron and unavoidable impurities are formed;

According to the computing formula of above-mentioned cold rolling rolling schedule, can draw table 3:

Table 3NAS H8403.5mm---0.43mm (500mm)

Passage	Pan feeding thickness mm	Discharging thickness mm	Forward pull (T)	Backward pull (T)
					1	3.5	2.72	21.3	6
2	2.72	2.2	21.3	12
					3	2.2	1.78	21.3	12
4	1.78	1.45	21.3	12
					5	1.45	1.18	21.3	12
6	1.18	0.96	18	11
					7	0.96	0.78	12	10
8	0.78	0.635	9.5	9
					9	0.635	0.52	7.5	7
10	0.52	0.43	6.5	6

Wherein, in cold-rolling process, the 1-2 passage is used the NO.1 working roll; The 3-4 passage is used the NO.1 working roll; The 5-6 passage is used the NO.2 working roll; The 7-8 passage is used the NO.2 working roll; 9 passages are used the NO.2 working roll; 10 passages are used the 2B working roll.In cold rolling back during two passages, pay special attention to check whether defectiveness of surface of steel plate, when cold rolling last passage, earlier about cold rolling 3～5 circles, stop and survey whether defectiveness of steel plate thickness and inspection surface of steel plate.If working roll causes defective must in time change (skid like working roll and cause serious aberration, defectives such as roller point) during production.Must standard check surface quality when cold rolling.Mechanical performance through the strip of steel plate behind the above-mentioned cold-rolling process is as shown in table 4 below:

The mechanical performance of table 4NAS H840

The above only is preferred embodiment of the present invention, is not the present invention is done any pro forma restriction; Though the present invention discloses as above with preferred embodiment; Yet be not in order to limiting the present invention, anyly be familiar with the professional and technical personnel, in not breaking away from technical scheme scope of the present invention; When the technology contents of above-mentioned announcement capable of using is made a little change or is modified to the equivalent embodiment of equivalent variations; In every case be not break away from technical scheme content of the present invention, to any simple modification, equivalent variations and modification that above embodiment did, all still belong in the scope of technical scheme of the present invention according to technical spirit of the present invention.

Claims (2)

1. the cold rolling process of an austenite stainless steel plate strip, it is characterized in that: this stainless steel plate strip contains following chemical composition, by percentage to the quality, C:0.10; Si:1.00, Mn:1.50, P:0.030, S:0.015; Ni:30～35, Cr:19～23, Cu:0.75; Al:0.15～0.60, Ti:0.15～0.60, surplus is that iron and unavoidable impurities are formed;

In the cold-rolling process step, calculate pan feeding, discharging thickness in the cold rolling rolling schedule, H: pan feeding thickness by following formula; H; Discharging thickness; H ₀: raw thickness, absolute draft amount Δ h=H-h,

Pass reduction ε=Δ h/H * 100%; Total working modulus

before the passage

Pass the total processing rate

pass the average processing rate?

In the cold-rolling process step, calculate the forward and backward tension value of passage in the cold rolling rolling schedule by following formula, wherein: q _HBe expressed as the preceding unit tension of strip of steel plate; q _hBe expressed as the back unit tension of strip of steel plate; It is wide that B is expressed as the plate of strip of steel plate;

Passage forward pull Q _H=q _H* B * H;

Passage backward pull Q _h=q _h* B * h;

Mean tension Q=(Q _h+ Q _H)/2.

2. the cold rolling process of an austenite stainless steel plate strip, it is characterized in that: this stainless steel plate strip contains following chemical composition, by percentage to the quality, C:0.08; Si:0.40～0.80, Mn:0.20～0.70, P:0.025; S:0.015, Ni:18～22, Cr:18～22; Al:0.20～0.60, Ti:0.20～0.60, surplus is that iron and unavoidable impurities are formed;

In the cold-rolling process step, calculate pan feeding, discharging thickness in the cold rolling rolling schedule, H: pan feeding thickness by following formula; H; Discharging thickness; H ₀: raw thickness, absolute draft amount Δ h=H-h;

Pass reduction ε=Δ h/H * 100%; Total working modulus

before the passage

Pass the total processing rate

pass the average processing rate

In the cold-rolling process step, calculate the forward and backward tension value of passage in the cold rolling rolling schedule by following formula, wherein: q _HBe expressed as the preceding unit tension of strip of steel plate; q _hBe expressed as the back unit tension of strip of steel plate; It is wide that B is expressed as the plate of strip of steel plate;

Passage forward pull Q _H=q _H* B * H;

Passage backward pull Q _h=q _h* B * h;

Mean tension Q=(Q _h+ Q _H)/2.

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