阅读说明：本技术 一种普通取向硅钢六辊五机架冷连轧一次冷轧工艺 (Cold rolling process for one time of cold continuous rolling of six-roller five-stand common oriented silicon steel ) 是由 商存亮 戚新军 崔占利 琚艳军 张学成 闫书伟 李恒 于 2020-12-10 设计创作，主要内容包括：本发明公开了一种普通取向硅钢六辊五机架冷连轧一次冷轧工艺,使普通取向硅钢的一次冷轧同样可以在酸洗轧机联合机组进行轧制。该工艺是将热轧原料卷在酸洗轧机联合机组完成,所述热轧原料卷的成分组成为：C：0.025～0.045wt%；Si：3.00～3.30wt%；Mn：0.15～0.25wt%；P：≤0.025wt%；S：0.004～0.015wt%；Als：0.010～0.025wt%；N：0.0070～0.0115wt%；Cu：0.45～0.55wt%；Ti：≤0.020wt%,其余为Fe和不可避免的杂质。本发明充分发挥酸洗轧机联合机组的兼容功能,上线开卷前原料不用蒸汽预热,入轧机前也不采用电磁感应加热,节省投资,满足研发生产冷轧普通取向硅钢需要。由于是连续轧制,提高了生产效率,提高了成材率,降低了成本。(The invention discloses a six-roller five-stand cold continuous rolling one-step cold rolling process for common oriented silicon steel, which can enable the common oriented silicon steel to be rolled in a pickling and rolling mill combined unit at the same time. The process is implemented by finishing a hot rolling raw material coil in an acid pickling rolling mill combined unit, wherein the hot rolling raw material coil comprises the following components: c: 0.025 to 0.045 wt%; si: 3.00-3.30 wt%; mn: 0.15-0.25 wt%; p: less than or equal to 0.025 wt%; s: 0.004-0.015 wt%; and Als: 0.010-0.025 wt%; n: 0.0070-0.0115 wt%; cu: 0.45-0.55 wt%; ti: less than or equal to 0.020wt%, and the balance of Fe and inevitable impurities. The invention gives full play to the compatible function of the pickling and rolling mill combined unit, the raw materials are not preheated by steam before being put on line and uncoiled, and the raw materials are not heated by electromagnetic induction before being put into a rolling mill, thereby saving investment and meeting the requirements of developing and producing cold-rolled common oriented silicon steel. Because the continuous rolling is adopted, the production efficiency is improved, the yield is improved, and the cost is reduced.)

1. A cold rolling process for one time of cold continuous rolling of a common oriented silicon steel six-roller five-stand is characterized in that the process is to finish a hot rolling raw material roll in an acid pickling rolling mill combined unit, wherein the hot rolling raw material roll comprises the following components: c: 0.025 to 0.045 wt%; si: 3.00-3.30 wt%; mn: 0.15-0.25 wt%; p: less than or equal to 0.025 wt%; s: 0.004-0.015 wt%; and Als: 0.010-0.025 wt%; n: 0.0070-0.0115 wt%; cu: 0.45-0.55 wt%; ti: less than or equal to 0.020wt%, and the balance of Fe and inevitable impurities.

2. The cold rolling process for one time of the cold continuous rolling of the common oriented silicon steel by the six-roller five-stand cold rolling mill is characterized by comprising the following steps of:

(1) specification of hot-rolled raw material coil: the thickness is 2-2.5 mm, and the width is 1000-1350 mm;

(2) controlling the insertion depth of the roller box of the straight head machine: specifically, the insertion depth of a 1# straight-head machine roller box is controlled to be-12 mm, the insertion depth of a 2# straight-head machine roller box is controlled to be-12 mm, and the insertion depth of a 3# straight-head machine roller box is controlled to be 4 mm;

(3) controlling the working parameters of the laser welding machine: the welding power is 12kW, the welding speed is 6.3mpm, the welding seam gap is-0.5 mm, the wire feeding speed is 3.0mpm, and the annealing current is 150A;

(4) a withdrawal and straightening machine: the elongation is 0.2%;

(5) acid washing section: the pickling speed is 80-100 mpm, the acid liquor temperature is 85 ℃, the free acid is more than or equal to 100g/L, and 1m hydrochloric acid is added into each roll³(ii) a The dosage of the corrosion inhibitor is as follows: mixing hydrochloric acid and a corrosion inhibitor according to the mass ratio of 1000:1, wherein the adding speed of the corrosion inhibitor is 1kg/3 min;

(6) disc shearing: the gap between the cutting edges is 0.25mm, and the overlapping amount is 0.56 mm;

(7) loop quantity: the inlet loop quantity and the outlet loop quantity are controlled within 50 percent;

(8) controlling the insertion depth of a three-roller stabilizing roller at the inlet of the rolling mill to be 15-25 mm;

(9) diameter of the working roll: S1-S3: phi is 400-420 mm; S4-S5: phi is 390-400 mm;

(10) roughness of the working roll: S1-S3: 0.6 μm; S4-S5: 0.2 μm;

(11) diameter of the intermediate roll: phi is 500-515 mm;

(12) diameter of the supporting roller: 1270-1285 mm phi;

(13) exit speed of rolling: 260-350 mpm;

(14) controlling rolling force of five stands from S1 to S5: s1: 12120KN, S2: 11384KN, S3: 11301KN, S4: 10755KN, S5: 11625 KN;

(15) controlling the temperature of the emulsion to be 50 ℃, the pH value to be 6.2 and the concentration to be 2.5-3.0 wt%;

(16) controlling the tension distribution of the racks from S1 to S5 to be increased step by step, specifically: distributing tension: entrance of S1: 40-41 MPa, S1-S2: 94-96 MPa, S2-S3: 105 to 110 MPa, S3 to S4: 120-125 MPa, S4-S5: 125-128 MPa, and an S5 outlet: 61-63 MPa;

(17) and controlling the reduction rate of the rack from S1 to S5 to be gradually reduced, specifically: the reduction rate is as follows: s1: 23-24%, S2: 23-24%, S3: 22-23%, S4: 22-23%, S5: 17-18%.

Technical Field

The invention belongs to the technology of oriented silicon steel rolling technology, and particularly relates to a one-step cold rolling technology for cold continuous rolling of a six-roller five-stand common oriented silicon steel.

Background

The oriented silicon steel strip is a novel functional magnetic material, and because the oriented silicon steel strip has large resistance, the electric energy consumed on an iron core is small in the operation process; because the magnetization of the iron core has strong directionality, the iron core has high magnetic induction in the required direction, high utilization rate of the iron core and high operation efficiency, and the oriented silicon steel strip is the most key and most main iron core material in electromagnetic orientation conversion products such as transformers, mutual inductors and the like. The oriented silicon steel is mainly classified into general oriented silicon steel and high magnetic induction oriented silicon steel. The oriented silicon steel strip has the advantages of complex production process, narrow parameter window, long working procedure and high technical content, and is known as an artwork in steel products.

The production process flow of the common oriented silicon steel comprises the following steps: hot rolling coil → acid cleaning → first cold rolling → decarburization annealing → second cold rolling → magnesium oxide coating → high temperature annealing → stretching and flattening annealing → longitudinal shearing edge → inspection, packaging and weighing for warehousing.

And (3) carrying out cold rolling repeatedly for 3-4 times on the pickled hot-rolled coil by adopting a single-stand reversible rolling mill usually in the primary cold rolling, wherein the reduction rate is 60-70%, and a primary cold-rolled product with the thickness within a certain range is obtained.

The single-stand reversible repeated rolling is adopted in the one-time cold rolling, the production efficiency is low, the yield is low, and the cost is high. In recent years, manufacturers try to produce the cold continuous rolling mill set, but in order to realize stable plate passing, the raw materials are preheated by steam before being fed on line and uncoiled, and are heated by electromagnetic induction before being fed into a rolling mill, so that the process layout difficulty is high, the investment is high, and the cost is increased.

In the production process, chemical elements can have certain influence on the performance of the oriented silicon steel, and the method specifically comprises the following steps:

1. mn and S: MnS is an important inhibitor in the oriented silicon steel, and after primary crystallization and secondary recrystallization are completed, S remains in a finished product and is harmful to magnetism, so that MnS mass points are decomposed at a high-temperature annealing and high-heat-preservation stage in a pure hydrogen atmosphere, sulfur is diffused and volatilized, and steel purification is realized.

2. Al, N: AlN is a main inhibitor in the oriented silicon steel, and N can be added during steel making and can be subjected to nitriding treatment after decarburization so as to increase the inhibitor amount and improve secondary recrystallization. After the secondary recrystallization is finished, N can also cause the product to generate harmful elements of magnetic aging, and needs to be purified and removed.

3. Cu: cu can make Cu₂S is greatly separated out, and the inhibition capability is improved. Since the oxide layer on the surface of the steel sheet contains CuO, the decarburization efficiency is lowered, and thus the oxide layer on the surface must be completely removed by a chemical or mechanical method before cold rolling.

4. Si: si has no inhibiting effect, but the addition of Si can obviously increase the resistivity of the steel, reduce the eddy current loss and improve the magnetic permeability. The increase of the Si content can increase the brittleness of the steel plate and increase the production difficulty.

5. C: in the multi-component inhibitor, the magnetic induction can be improved and the iron loss can be reduced by increasing the content of C, but the magnetic aging phenomenon can be generated by overhigh C in the finished product.

6. Ni: ni can stabilize secondary recrystallization, improve magnetic induction and reduce iron loss, and the problem of magnetic induction reduction caused by silicon content increase can be solved by adding Ni.

7. Ti: TiC and TiN can be used as inhibitors, but an excessive amount of titanium causes a decrease in the amount of AlN deposited and a decrease in magnetic properties.

8. P: p can make inhibitor particles finer and more uniformly distributed and improve magnetism, but too much P can reduce cold brittleness of the plate and increase cold rolling difficulty, and a proper amount is needed.

Disclosure of Invention

The invention aims to provide a six-roller five-stand cold continuous rolling one-step cold rolling process for common oriented silicon steel, so that the common oriented silicon steel can be rolled in a pickling and rolling mill combined unit by one-step cold rolling. The invention gives full play to the compatible function of the pickling and rolling mill combined unit, the raw materials are not preheated by steam before being put on line and uncoiled, and the raw materials are not heated by electromagnetic induction before being put into a rolling mill, thereby saving investment and meeting the requirements of developing and producing cold-rolled common oriented silicon steel. Because the continuous rolling is adopted, the production efficiency is improved, the yield is improved, and the cost is reduced.

In order to achieve the purpose, the invention adopts the technical scheme that:

a cold rolling process for one-step cold rolling of a common oriented silicon steel six-roller five-stand cold continuous rolling mill is completed by a hot rolling raw material roll in an acid pickling rolling mill combined unit, wherein the hot rolling raw material roll comprises the following components: c: 0.025 to 0.045 wt%; si: 3.00-3.30 wt%; mn: 0.15-0.25 wt%; p: less than or equal to 0.025 wt%; s: 0.004-0.015 wt%; and Als: 0.010-0.025 wt%; n: 0.0070-0.0115 wt%; cu: 0.45-0.55 wt%; ti: less than or equal to 0.020wt%, and the balance of Fe and inevitable impurities.

Further, the process specifically comprises the following steps:

(1) specification of hot-rolled raw material coil: the thickness is 2-2.5 mm, and the width is 1000-1350 mm;

(2) controlling the insertion depth of the roller box of the straight head machine: specifically, the insertion depth of a 1# straight-head machine roller box is controlled to be-12 mm, the insertion depth of a 2# straight-head machine roller box is controlled to be-12 mm, and the insertion depth of a 3# straight-head machine roller box is controlled to be 4 mm;

(3) controlling the working parameters of the laser welding machine: the welding power is 12kW, the welding speed is 6.3mpm, the welding seam gap is-0.5 mm, the wire feeding speed is 3.0mpm, and the annealing current is 150A;

(4) a withdrawal and straightening machine: the elongation is 0.2%;

(5) acid washing section: the pickling speed is 80-100 mpm, the acid liquor temperature is 85 ℃, the free acid is more than or equal to 100g/L, and 1m hydrochloric acid is added into each roll³(ii) a The dosage of the corrosion inhibitor is as follows: mixing hydrochloric acid and a corrosion inhibitor according to the mass ratio of 1000:1, wherein the adding speed of the corrosion inhibitor is 1kg/3 min;

(6) disc shearing: the gap between the cutting edges is 0.25mm, and the overlapping amount is 0.56 mm;

(7) loop quantity: the inlet loop quantity and the outlet loop quantity are controlled within 50 percent;

(8) controlling the insertion depth of a three-roller stabilizing roller at the inlet of the rolling mill to be 15-25 mm;

(9) diameter of the working roll: S1-S3: phi is 400-420 mm; S4-S5: phi is 390-400 mm;

(10) roughness of the working roll: S1-S3: 0.6 μm; S4-S5: 0.2 μm;

(11) diameter of the intermediate roll: phi is 500-515 mm;

(12) diameter of the supporting roller: 1270-1285 mm phi;

(13) exit speed of rolling: 260-350 mpm;

(14) controlling rolling force of five stands from S1 to S5: s1: 12120KN, S2: 11384KN, S3: 11301KN, S4: 10755KN, S5: 11625 KN;

(15) controlling the temperature of the emulsion to be 50 ℃, the pH value to be 6.2 and the concentration to be 2.5-3.0 wt%;

(16) controlling the tension distribution of the racks from S1 to S5 to be increased step by step, specifically: distributing tension: entrance of S1: 40-41 MPa, S1-S2: 94-96 MPa, S2-S3: 105 to 110 MPa, S3 to S4: 120-125 MPa, S4-S5: 125-128 MPa, and an S5 outlet: 61-63 MPa;

(17) and controlling the reduction rate of the rack from S1 to S5 to be gradually reduced, specifically: the reduction rate is as follows: s1: 23-24%, S2: 23-24%, S3: 22-23%, S4: 22-23%, S5: 17-18%.

Further, the concentration of the hydrochloric acid in the step (5) is 18wt%, and the density of the corrosion inhibitor is 1.1g/cm³The method reduces the defect of over-pickling in the pickling process, improves the surface glossiness and cleanliness of the strip steel, and can adopt the Lan-1826 corrosion inhibitor of ZiboTungda new technology development company Limited.

Further, after the continuous cold rolling of six rollers and five frames for one time, the crystal grains of the common oriented silicon steel are fibrous or flat, the crystal grains extend along the rolling direction, the Goss texture in the hot rolled plate disappears, and the texture is mainly alpha and gamma texture.

Compared with the prior art, the invention has the beneficial effects that:

1. the hot rolling raw material coil used for the primary cold rolling needs to be added with an inhibitor, the main effect is to keep the crystal shape of the common oriented silicon steel product stable and uniform and prevent the reduction of the magnetization of the product, and the added MnS contains 0.15-0.25 wt% of Mn and 0.004-0.015 wt% of S. The thickness of the hot-rolled raw material coil is 2-2.5 mm, and the width of the hot-rolled raw material coil is 1000-1350 mm; the method is subjected to one-time cold rolling through six-roller five-frame cold continuous rolling, the final rolling thickness is 0.63mm, and the reduction rate is 65-75%, so that the accuracy of the (110) [ 001 ] crystal grain orientation generated in the subsequent one-time decarburization process of intermediate annealing is ensured by the reduction rate.

2. The common oriented silicon steel hot rolling raw material coil is hard and brittle, the iron scale is not easy to remove, and the strip breakage accident is easy to occur in the production process. In order to improve the stability of the inlet section through plate, reduce broken belts, reasonably control the insertion depth of a roller box of a straight-head machine and improve the welding quality, the elongation of the tension leveler is controlled to be 0.2 percent, and the loop quantity of an inlet and an outlet is controlled to be within 50 percent; in order to ensure the pickling quality, the pickling speed, the acid liquor temperature and the concentration are strictly controlled, and a corrosion inhibitor is added; in order to reduce the rolling force, prevent the rolling force from exceeding the limit and ensure the rolling stability and the product quality, the diameter of a working roll is controlled below 420mm, the roughness is controlled to be 0.2-0.6 mu m, the concentration of an emulsion is improved to 2.5-3.0 wt%, the tension distribution of five stands from S1 to S5 is gradually and properly increased, and the reduction rate of the five stands from S1 to S5 is gradually and properly reduced.

3. After the six-roller five-stand cold continuous rolling is adopted for one-time cold rolling, the crystal grains of the common oriented silicon steel are fibrous or flat, the crystal grains extend along the rolling direction, the Goss texture in the hot rolled plate disappears, the texture is mainly alpha and gamma, and the same effect as that after the one-time cold rolling is carried out by a single-stand reversible rolling mill is achieved.

Detailed Description

The technical solutions and effects of the present invention will be further described with reference to specific examples, but the scope of the present invention is not limited thereto.

Example 1

The cold rolling process of the common oriented silicon steel six-roller five-stand cold continuous rolling is completed in the pickling and rolling mill combined unit. Hot rolling of the raw material roll: c: 0.039 wt%; si: 3.15 wt%; mn: 0.18 wt%; p: 0.021 wt%; s: 0.008 wt%; and Als: 0.015 wt%; n: 0.009 wt%; cu: 0.48 wt%; ti: 0.012wt%, the balance being Fe and inevitable impurities; the thickness of the hot rolling raw material is 2.3 mm; after the primary cold rolling is finished, the post-working procedure is carried out according to the conventional method, and the performance of the finished product can meet the standard.

Example 2

The cold rolling process of the common oriented silicon steel six-roller five-stand cold continuous rolling is completed in the pickling and rolling mill combined unit. Hot rolling of the raw material roll: c: 0.035 wt%; si: 3.23 wt%; mn: 0.20 wt%; p: 0.022 wt%; s: 0.007 wt%; and Als: 0.017 wt%; n: 0.011 wt%; cu: 0.49 wt%; ti: 0.009wt%, the balance being Fe and inevitable impurities; the thickness of the hot rolling raw material is 2.5 mm; after the primary cold rolling is finished, the post-working procedure is carried out according to the conventional method, and the performance of the finished product can meet the standard.

The hot rolling raw material coil of the cold-rolled common oriented silicon steel is finished in a pickling and rolling mill combined unit by adopting a six-roller five-stand cold continuous rolling one-step cold rolling process. The technological process of the pickling and rolling mill combined unit comprises the following steps: uncoiling → cutting head and tail → welding → straightening → acid washing → trimming → deburring → rolling → shearing → coiling → weighing → bundling → warehousing. The parameters of the single cold rolling process of the six-roller five-stand cold continuous rolling of the common oriented silicon steel in the embodiment 1 and the embodiment 2 of the invention are shown in table 1.

Table 1 six-roll five-stand cold continuous rolling process for common oriented silicon steel in accordance with the embodiments of the present invention

Examples	1	2
			Hot rolling raw material coil Thickness of	2.3mm	2.5mm
Straight head machine roller box Depth of insertion	1#、2#：-12mm，3#：4mm	1#、2#：-12mm，3#：4mm
			Laser welder	Welding power is 12kW, welding speed is 6.3mpm, welding seam gap is-0.5 mm, and wire feeding speed is high Degree 3.0mpm, annealing current 150A	Welding power is 12kW, welding speed is 6.3mpm, welding seam gap is-0.5 mm, and wire feeding speed is high Degree 3.0mpm, annealing current 150A
Withdrawal and straightening machine	The elongation is 0.2 percent	The elongation is 0.2 percent
			Acid washing section	The pickling speed is 85mpm, the acid liquor temperature is 85 ℃, the free acid is more than or equal to 100g/L, and the acid is added in each roll 1m of 18% hydrochloric acid3(ii) a The application of the corrosion inhibitor comprises the following dosage: hydrochloric acid and corrosion inhibitor according to the mass Mixing at a ratio of 1000:1, and adding the corrosion inhibitor at a speed of 1kg/3min	The pickling speed is 90mpm, the temperature of the acid liquor is 85 ℃, the free acid is more than or equal to 100g/L, and the acid is added in each roll 1m of 18% hydrochloric acid3(ii) a The application of the corrosion inhibitor comprises the following dosage: hydrochloric acid and corrosion inhibitor according to the mass Mixing at a ratio of 1000:1, and adding the corrosion inhibitor at a speed of 1kg/3min
Circle shear	The blade gap is 0.25mm, and the overlap is 0.56mm	The blade gap is 0.25mm, and the overlap is 0.56mm
			Loop amount	The inlet loop quantity and the outlet loop quantity are controlled within 50 percent;	the inlet loop quantity and the outlet loop quantity are controlled within 50 percent;
inlet III of rolling mill Roller stabilizing roller	The insertion depth is 22mm	The insertion depth is 18mm
			Diameter of work roll	S1~S3：Φ410mm；S4~S5：Φ395mm	S1~S3：Φ400mm；S4~S5：Φ390mm
Roughness of the working roll Degree of rotation	S1~S3：0.6μm；S4~S5：0.2μm	S1~S3：0.6μm；S4~S5：0.2μm
			Diameter of intermediate roll	Φ512mm	Φ512mm
Diameter of support roller	Φ1280mm	Φ1280mm
			Exit speed of rolling Degree of rotation	280~350mpm	260~300mpm
Rolling force	S1：12120KN；S2：11384KN；S3：11301KN；S4：10755KN；S5： 11625KN	S1：12120KN；S2：11384KN；S3：11301KN；S4：10755KN；S5： 11625KN
			Emulsion liquid	The temperature is 50 ℃, the pH value is 6.2, and the concentration is carried outDegree 2.5wt%	The temperature is 50 ℃, the pH value is 6.2, and the concentration is 2.7wt%
Tension distribution	Entrance of S1: 40-41 MPa; S1-S2: 94-96 MPa; S2-S3: 105 to 109 MPa; S3-S4: 120-124 MPa; S4-S5: 125-127 MPa; and an outlet of S5: 61~62MPa	entrance of S1: 40-41 MPa; S1-S2: 95-96 MPa; S2-S3: 108 to 110 MPa; S3-S4: 122-125 MPa; S4-S5: 126-128 MPa; and an outlet of S5: 62~63 MPa
			reduction ratio	S1：23~24%；S2：23~24%；S3：22~23%；S4：22~23%；S5：17~18%	S1：23~24%；S2：23~24%；S3：22~23%；S4：22~23%；S5：17~18%
After one-time cold rolling Thickness of hard rolled product Degree of rotation	0.63mm	0.63mm
			After one-time cold rolling Edge of hard rolled product Descend	＜0.01mm	＜0.01mm
After one-time cold rolling Crystal of rolled hard product Granule shape	Fibrous form	Fibrous form
			After one-time cold rolling Rolled hard product weave Structure of the organization	Goss texture disappears, mainly alpha and gamma texture	The Goss texture disappears, mainly being alpha,Gamma texture
After the conventional treatment Final product of the process Product brand number	27Q120	27Q130
			After the conventional treatment Final product of the process Core loss value of product	P1.7/50 is 117W/kg	P1.7/50 is 126W/kg

The six-roller five-rack cold continuous rolling process is simple and reasonable, the pickling and rolling mill combination unit is adopted to perform cold rolling on the common oriented silicon steel hot-rolled raw material coil once, the post-process is performed according to the convention, and the performance of the finished product can meet the standard.

The invention not only enables the common oriented silicon steel to be rolled on a cold continuous rolling mill set by one-time cold rolling, but also can improve the production efficiency and reduce the cost.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.