阅读说明：本技术 一种含磷无铝高效无取向硅钢生产方法 (Production method of phosphorus-containing aluminum-free high-efficiency non-oriented silicon steel ) 是由 高振宇 陈春梅 李亚东 刘文鹏 罗理 李元华 王越 张仁波 姜福健 周旭 于 2021-08-19 设计创作，主要内容包括：本发明涉及一种含磷无铝高效无取向硅钢生产方法,生产方法取消常化工艺,具体步骤如下：1)将钢水冶炼至目标成分后,浇铸成坯；2)板坯热装,热装温度≥500℃,热轧板坯加热炉均热段板坯温度1150～1200℃；终轧温度控制在860～930℃,卷取温度700～800℃3)酸洗后冷轧,控制冷轧整体压下率80％以内,至成品厚度；4)连续退火炉快速加热段温度设定1050～1180℃,增加有利织构组织形核,均热段温度设定830～950℃,全氮气干气氛保护,退火工艺速度120～150m/min,满足晶粒度8～4级。本发明不需进行热轧卷常化处理,降低了制造成本。(The invention relates to a production method of phosphorus-containing aluminum-free high-efficiency non-oriented silicon steel, which cancels a normalizing process and comprises the following specific steps: 1) smelting the molten steel to a target component, and casting to form a blank; 2) hot charging the slab, wherein the hot charging temperature is more than or equal to 500 ℃, and the slab temperature of a soaking section of a hot rolling slab heating furnace is 1150-1200 ℃; the final rolling temperature is controlled to be 860-930 ℃, the coiling temperature is 700-800 ℃ 3), cold rolling is carried out after acid pickling, and the overall reduction rate of the cold rolling is controlled within 80% until the thickness of a finished product is reached; 4) the temperature of a rapid heating section of the continuous annealing furnace is set to be 1050-1180 ℃, the nucleation of a texture structure is increased, the temperature of a soaking section is set to be 830-950 ℃, the protection of the full nitrogen dry atmosphere is carried out, the speed of the annealing process is 120-150 m/min, and the grain size is 8-4 grade. The invention does not need to carry out the normalizing treatment of the hot rolled coil, thereby reducing the manufacturing cost.)

1. the production method of the phosphorus-containing aluminum-free high-efficiency non-oriented silicon steel is characterized in that the steel contains the following chemical components: c is less than or equal to 0.0027 percent, and Si: 0.15-1.70%, Als is less than or equal to 0.0010%, Mn: 0.35 to 0.85 percent of Fe, 0.050 to 0.2 percent of P, less than or equal to 0.0020 percent of S, less than or equal to 0.0020 percent of N, 0.015 to 0.045 percent of Cu, less than or equal to 0.0020 percent of Ti, V and Nb, and the balance of Fe and inevitable residual elements; the production method does not need to carry out normalizing treatment and comprises the following specific steps:

1) smelting the molten steel to a target component, and casting to form a blank;

2) hot charging the slab, wherein the hot charging temperature is more than or equal to 500 ℃, and the slab temperature of a soaking section of a hot rolling slab heating furnace is 1150-1200 ℃; the final rolling temperature is controlled to be 860-930 ℃, and the coiling temperature is controlled to be 700-800 DEG C

3) Cold rolling is carried out after acid cleaning, and the integral reduction rate of the cold rolling is controlled within 80 percent until the thickness of a finished product is reached;

4) the temperature of a rapid heating section of the continuous annealing furnace is set to 1050-1180 ℃, the temperature of a soaking section is set to 830-950 ℃, the protection of the full nitrogen dry atmosphere is carried out, the speed of the annealing process is 120-150 m/min, and the grain size is 8-4 grade.

Technical Field

The invention relates to the field of metallurgy, in particular to a production method of phosphorus-containing aluminum-free high-efficiency non-oriented silicon steel.

Background

The non-oriented silicon steel is an important metal functional soft magnetic material and is widely applied to the manufacturing field of electromagnetic iron cores required by electromagnetic conversion of motors and the like. At present, the electromagnetic performance and comprehensive quality level of domestic related products reach the advanced level in the world, the product competition is intensified day by day, and the non-oriented electrical steel variety with high efficiency, low cost, short flow, high performance and competitiveness becomes the consensus of each mainstream production enterprise.

With the progress of modern metallurgical technology, the steel cleanliness level is greatly improved, and the steel becomes the basis for the design optimization and adjustment of the components of the traditional non-oriented silicon steel grade; the functions of main alloy reduction and microalloy elements are combined with the exertion of the whole process capability, and the method also becomes the direction of efficient conversion and development of electromagnetic performance of products.

In the traditional production of non-oriented electrical steel, with the increase of grades, silicon and aluminum as main alloy elements play a main role in improving resistivity and iron loss indexes, but also reduce the steel saturation magnetic induction intensity and reduce the magnetic induction indexes. The traditional phosphorus-containing and aluminum-containing silicon steel has contradiction in cleanliness control, the strong reducibility of aluminum increases the standards of titanium-containing ferrophosphorus alloy and auxiliary materials, increases the purchase cost and increases the difficulty in reducing titanium of the system.

Nowadays, medium and low grade high-efficiency products (high magnetic induction and low iron loss products) become mainstream products required by development of downstream high-efficiency motor (low-loss and small-volume and high-power motor) industry, and electrical steel production enterprises also make technical innovation on product component design and process, so as to meet the competitive requirements of users and markets.

Disclosure of Invention

The invention aims to solve the technical problem of providing a production method of phosphorus-containing aluminum-free high-efficiency non-oriented silicon steel, which has low alloy cost and high electromagnetic performance.

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

a method for producing phosphorus-containing aluminum-free high-efficiency non-oriented silicon steel comprises the following chemical components: c is less than or equal to 0.0027 percent, and Si: 0.15-1.70%, Als is less than or equal to 0.0010%, Mn: 0.35 to 0.85 percent of Fe, 0.050 to 0.2 percent of P, less than or equal to 0.0020 percent of S, less than or equal to 0.0020 percent of N, 0.015 to 0.045 percent of Cu, less than or equal to 0.0020 percent of Ti, V and Nb, and the balance of Fe and inevitable residual elements; the production method cancels a normalizing process and comprises the following specific steps:

1) smelting the molten steel to a target component, and casting to form a blank;

2) hot charging the slab, wherein the hot charging temperature is more than or equal to 500 ℃, and the slab temperature of a soaking section of a hot rolling slab heating furnace is 1150-1200 ℃; the final rolling temperature is controlled to be 860-930 ℃, and the coiling temperature is controlled to be 700-800 DEG C

3) Cold rolling is carried out after acid cleaning, and the integral reduction rate of the cold rolling is controlled within 80 percent until the thickness of a finished product is reached;

4) the temperature of a rapid heating section of the continuous annealing furnace is set to be 1050-1180 ℃, the nucleation of a texture structure is increased, the temperature of a soaking section is set to be 830-950 ℃, the protection of the full nitrogen dry atmosphere is carried out, the speed of the annealing process is 120-150 m/min, and the grain size is 8-4 grade.

Role of the ingredients in the steel:

c: controlling grain boundary segregation of micro-alloy elements in the structure; the finished product is controlled not to be decarburized, and the high-efficiency production is realized;

si: matching with high Mn to control the two-phase region structure in the heat history;

mn: matching with silicon to control a dual-phase region structure, controlling inclusion and a second phase composition, and intensively forming and curing original silicon-manganese nitride composite precipitates;

p: the function of improving the resistivity is exerted, grain boundary segregation is realized, other precipitates are inhibited from polymerizing, and energy storage and growth under the rolling state of the texture component are increased;

cu: the method is combined with the process, so that the compound precipitation and coarsening of copper sulfide and manganese sulfide are promoted, the hot rolling and cold rolling processability of the phosphorus-containing steel is improved, and the energy storage of unfavorable texture components is reduced;

ti, V, Nb: the system is controlled to clean steel, the designed elements of phosphorus and copper are exerted, and the influence of adverse nitride precipitates is reduced.

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

1. the invention is suitable for a cold-rolled non-oriented silicon steel metallurgical process production line, can be realized on the basis of certain steel cleanliness control in the traditional production line, does not need to transform process equipment, does not need to carry out normalizing treatment on hot-rolled coils, and reduces the manufacturing cost.

2. The alloy reduction and the cost reduction are realized on the basis of relatively reducing the silicon alloy amount and controlling without aluminum; the electromagnetic performance of the product is high-efficient through microalloy design and main process parameter control, and the market competitiveness of the product is improved.

3. The requirements of hydrogen and nitrogen protective gas and the wet atmosphere decarburization in the traditional heat treatment process are changed, and the process cost is reduced; and the control of a relatively fine grain structure improves the operating efficiency of the unit.

Detailed Description

The invention is further illustrated by the following examples:

the following examples describe the invention in detail. These examples are merely illustrative of the best embodiments of the present invention and do not limit the scope of the invention.

A method for producing phosphorus-containing aluminum-free high-efficiency non-oriented silicon steel comprises the following chemical components: c: less than or equal to 0.0027 percent, Si: 0.15% -1.70%, Als: less than or equal to 0.0010 percent, Mn: 0.35 to 0.85 percent of Fe, 0.050 to 0.2 percent of P, less than or equal to 0.0020 percent of S, less than or equal to 0.0020 percent of N, 0.015 to 0.045 percent of Cu, less than or equal to 0.0020 percent of Ti, V and Nb, and the balance of Fe and inevitable residual elements. The method cancels a normalizing process, and comprises the following specific process steps:

1. smelting the molten steel to a target component, and casting to form a blank;

2. the slab is hot-charged, the hot-charging temperature is more than or equal to 500 ℃, and the aggregation and coarsening of precipitates in the steel are facilitated; providing for maintaining or reducing conventional heating process times; the temperature of the slab at the soaking section of the hot-rolled slab heating furnace is more than or equal to 1150-1200 ℃, the precipitation amount of precipitates can be increased along with the reduction of the temperature in the hot rolling process by utilizing the solid solution difference of each precipitate in austenite and ferrite to specific precipitates, and the temperature can be further controlled by controlling the temperature; controlling the finishing temperature to be 860-930 ℃; coiling at 700-800 ℃, and increasing the proportion of recrystallized structures;

3. cold rolling is carried out after acid washing, the integral reduction rate of the cold rolling is controlled within 80 percent until the thickness of a finished product is reached, a deformation structure is increased, and a shear band is increased, so that the fine grain structure of the finished product and the ratio of favorable components can be increased because the favorable texture components are easy to nucleate at the position of the shear band;

4. the temperature of a rapid heating section of the continuous annealing furnace is set to be 1050-1180 ℃, the nucleation of a texture structure is increased, the temperature of a soaking section is set to be 830-950 ℃, the protection of the full nitrogen dry atmosphere is carried out, the speed of the annealing process is 120-150 m/min, and the grain size is 8-4 grade.

The grain size is 8-4 grade, the control of a relatively fine grain structure is realized, and the re-coarsening of a specific precipitate is inhibited.

Example 1:

a method for producing phosphorus-containing aluminum-free high-efficiency non-oriented silicon steel comprises the following chemical components in percentage by mass: c: 0.0025%, Si: 1.60%, Mn: 0.55%, P: 0.10%, S: 0.0015%, Als: 0.001%, N: 0.0015%, Cu 0.035%, Ti: 0.0018%, V: 0.0015%, Nb: 0.0011 percent, and the balance of iron and inevitable impurity elements. The process route is as follows: the production method comprises the following steps of molten iron desulphurization, converter smelting, RH refining, continuous casting, hot rolling, acid cleaning, cold rolling, continuous furnace annealing, coating, performance inspection and packaging:

a) smelting and continuous casting: smelting in a converter, carrying out RH vacuum refining treatment, controlling the components of molten steel according to the requirements, and casting into a plate blank with the thickness of 230 mm;

b) and hot charging the plate blank, wherein the hot charging temperature is 560 ℃, the heating temperature is 1150 ℃, the plate blank is subjected to initial rolling to 40mm, and then the plate blank enters a finishing mill group for rolling. The initial rolling temperature of finish rolling is 1080 ℃, the final rolling temperature is 980 ℃, the coiling temperature is 750 ℃, and the thickness of the hot rolled plate is 2.2 mm;

c) cold rolling to 0.50mm after acid cleaning;

d) after cold rolling, the temperature of a continuous annealing rapid heating section is 1090 ℃, the temperature of a soaking section is 940 ℃, total nitrogen protection is carried out, the process speed is 130m/min, continuous annealing is carried out, and the grade of a grain structure is 5.0.

Example 2:

a method for producing phosphorus-containing aluminum-free high-efficiency non-oriented silicon steel comprises the following chemical components in percentage by mass: c: 0.0022%, Si: 0.75%, Mn: 0.60%, P: 0.15%, S: 0.0020%, Als: 0.0010%, N: 0.0018%, Cu 0.03%, Ti: 0.0011%, V: 0.0013%, Nb: 0.0012%, and the balance of iron and inevitable impurity elements. The process route is as follows: the production method comprises the following process steps of molten iron desulphurization, converter smelting, RH refining, continuous casting, hot rolling, acid cleaning, cold rolling, continuous furnace annealing, coating, performance inspection and packaging:

a) smelting and continuous casting: smelting in a converter, carrying out RH vacuum refining treatment, controlling the components of molten steel according to the requirements, and casting into a plate blank with the thickness of 230 mm;

b) and (3) hot charging the plate blank, wherein the hot charging temperature is 520 ℃, the heating temperature is 1180 ℃, and the plate blank enters a finishing mill group for rolling after being initially rolled to 40 mm. The initial rolling temperature of finish rolling is 1050 ℃, the final rolling temperature is 960 ℃, the coiling temperature is 750 ℃, and the thickness of the hot rolled plate is 2.2 mm;

c) cold rolling to 0.50mm after acid cleaning;

d) after cold rolling, the temperature of a continuous annealing rapid heating section is 1080 ℃, the temperature of a soaking section is 920 ℃, the temperature is protected by total nitrogen, the process speed is 135m/min, the continuous annealing is carried out, and the grade of the grain structure is 5.5.

Comparative example 1

The steel grade comprises the following chemical components in percentage by mass: c: 0.0023%, Si: 1.85%, Mn: 0.25%, P: 0.010%, S: 0.002%, Als: 0.35%, N: 0.0019% and the balance of iron and inevitable impurity elements.

Smelting in a converter, carrying out RH vacuum refining treatment, controlling the components of molten steel according to the requirements, and casting into a plate blank with the thickness of 230 mm; hot charging the plate blank, wherein the hot charging temperature is 400 ℃, the heating temperature is 1120 ℃, the plate blank is subjected to initial rolling to 40mm and then enters a finishing mill group for rolling, the starting rolling temperature of finish rolling is 1020 ℃, the finishing rolling temperature is 850 ℃, the coiling temperature is 700 ℃, and the thickness of the hot rolled plate is 2.3 mm; cold rolling is directly carried out on the steel strip with the thickness of 0.5mm, the annealing temperature of the finished product is 1050 ℃ and 940 ℃, hydrogen and nitrogen protection is carried out, the process speed is 130m/min, continuous annealing is carried out, and the grade of the grain structure is 4.5.

Comparative example 2

C: 0.0035%, Si: 0.85%, Mn: 0.28%, P: 0.009%, S: 0.0040%, Als: 0.30%, N: 0.0021 percent, and the balance of iron and inevitable impurity elements.

Smelting in a converter, carrying out RH vacuum refining treatment, controlling the components of molten steel according to the requirements, and casting into a plate blank with the thickness of 230 mm; hot charging the plate blank, wherein the hot charging temperature is 400 ℃, the heating temperature is 1120 ℃, the plate blank enters a finishing mill group for rolling after being initially rolled to 40mm, the finishing rolling start temperature is 970 ℃, the finishing rolling temperature is 850 ℃, the coiling temperature is 710 ℃, and the thickness of the hot rolled plate is 2.5 mm; cold rolling is directly carried out on the steel strip with the thickness of 0.5mm, the annealing temperature of the finished product is 1050 ℃ and 920 ℃, hydrogen and nitrogen protection is carried out, the process speed is 135m/min, continuous annealing is carried out, and the grade of the grain structure is 5.5.

The examples are compared with the comparative examples in table 1, table 2:

table 1:

table 2: