阅读说明：本技术 一种横向可变厚度的宽幅普通碳锰钢板及其制备方法 (Transverse thickness-variable wide common carbon-manganese steel plate and preparation method thereof ) 是由 朱岩 陈超 李占杰 于 2018-06-28 设计创作，主要内容包括：一种横向可变厚度的宽幅普通碳锰钢板及其制备方法,该钢板厚度在宽度方向上分区段单调线性增加或减小；钢板的纵截面为长方形,钢板的横截面为直角梯形或若干直角梯形与长方形组成,且具有该截面的一张钢板经水平方向与垂直方向各旋转180°后,与另一块具有同样截面的钢板叠合组成一个长方体；钢板的最大板厚与最小板厚之差不超过20mm,最大板厚与最小板厚之比不超过3:1,最大板厚与最小板厚之差与宽度之比不超过1:300；所述钢板可以是轧态交货的钢板,也可以是正火态交货的钢板。本发明所述钢板可通过现有加热、轧钢及正火热处理设备,采用成熟的加热、轧钢和正火热处理工艺,经济地、批量地生产。(A horizontal variable-thickness wide-width common carbon-manganese steel plate and a preparation method thereof are provided, wherein the thickness of the steel plate is monotonically and linearly increased or decreased in sections in the width direction; the longitudinal section of the steel plate is rectangular, the cross section of the steel plate is a right trapezoid or consists of a plurality of right trapezoids and a rectangle, and one steel plate with the section is superposed with another steel plate with the same section to form a cuboid after being respectively rotated by 180 degrees in the horizontal direction and the vertical direction; the difference between the maximum plate thickness and the minimum plate thickness of the steel plate is not more than 20mm, the ratio of the maximum plate thickness to the minimum plate thickness is not more than 3:1, and the ratio of the difference between the maximum plate thickness and the minimum plate thickness to the width is not more than 1: 300; the steel plate can be a rolled steel plate or a normalized steel plate. The steel plate can be economically produced in batch by adopting mature heating, steel rolling and normalizing heat treatment processes through the existing heating, steel rolling and normalizing heat treatment equipment.)

1. A wide-width common carbon-manganese steel plate with a transversely variable thickness is characterized in that the thickness of the steel plate is monotonically and linearly increased or decreased in sections in the width direction; one of the upper surface and the lower surface of the steel plate is a non-horizontal plane which is a slope plane and is inclined in a segmented way, and the other surface of the steel plate is a horizontal plane; the longitudinal section of the steel plate is rectangular, the cross section of the steel plate is a right-angled trapezoid or consists of a plurality of right-angled trapezoids and a rectangle, after one steel plate with the section is rotated by 180 degrees in the horizontal direction and the vertical direction, the slope surface of the steel plate is attached to the slope surface of the other steel plate with the same section, and the two steel plates are overlapped to form a cuboid, namely a overlapped differential thick steel plate; the difference between the maximum plate thickness and the minimum plate thickness of the steel plate is not more than 20mm, the ratio of the maximum plate thickness to the minimum plate thickness is not more than 3:1, and the ratio of the difference between the maximum plate thickness and the minimum plate thickness to the width is not more than 1: 300.

2. The transversely variable thickness wide plain carbon manganese steel sheet according to claim 1, wherein said steel sheet is a rolled or normalized steel sheet.

3. The method for manufacturing a wide plain carbon manganese steel sheet with a laterally variable thickness according to claim 1 or 2, comprising the steps of:

1) preparation of superimposed blanks

The device is formed by overlapping two intermediate blanks with the same shape and size, wherein one of the upper surface and the lower surface of the intermediate blank is a non-horizontal plane with a slope surface, namely a slope surface, and the other surface of the intermediate blank is a horizontal plane; the geometric shape of one section of the cross section and the longitudinal section is a right trapezoid or a polygon formed by a plurality of right trapezoids and rectangles, namely a differential thickness surface, and the geometric shape of the other section of the cross section is a rectangle;

the ratio of the thickness Hx of the middle blank at a certain point in the width direction to the thickness Tx of the finished differential thickness steel plate at the corresponding position, namely the compression ratio, is controlled to be 2-6 times, wherein the compression ratio of the thicker side is larger than that of the thinner side; for hot continuous rolling and steckel rolling mills, the width Wp of the intermediate blank is greater than the width W of the finished product differential thick steel plate, and the reversible wide and thick plate rolling mill has no limitation;

2) the slope surfaces of the two intermediate blanks are subjected to leveling and surface cleaning treatment to remove surface defects such as cracks, slag inclusions, pits and the like visible to the naked eye and high-temperature iron scales, so that the finished poor-thickness steel plate is ensured to obtain good surface quality;

3) the peripheries of the two middle blanks are subjected to groove processing, and a slope surface of one of the two middle blanks is coated or covered with a separant; after the other intermediate blank is rotated by 180 degrees in the horizontal direction and the vertical direction respectively, the slope surface of the other intermediate blank is superposed with the slope surface of the intermediate blank coated or covered with the separant to form a superposed blank;

4) carrying out discontinuous welding on the superposed blank along the middle groove gap;

5) manufacture of differential thickness steel plate

Heating, rolling and straightening the superposed blank by the same heating, rolling and straightening processes as those of a flat steel plate of the same steel type to obtain a superposed differential thick steel plate, wherein the thickness Tz of the superposed differential thick steel plate is larger than the sum of the maximum thickness and the minimum thickness of the differential thick steel plate, the width Wz of the superposed differential thick steel plate is larger than the width W of the differential thick steel plate, and the length Lz of the superposed differential thick steel plate is larger than the length L of the differential thick steel plate;

the width allowance of the superposed differential thick steel plate is cut off by adopting hot straightening, cold straightening and trimming, and the lower two layers of steel plates are separated into two non-sized differential thick plates;

if the differential thick steel plate is a rolled delivered steel plate, directly cutting the two unsettled differential thick plates to length, and cutting off the length allowance to finally obtain two transversely variable-thickness wide common carbon manganese steel plates with required dimension and specification;

if the differential thick steel plate is a steel plate delivered in a normalized state, the two non-sized differential thick plates are sent into a normalizing heat treatment furnace for normalizing treatment; the normalizing process of the two steel plates with the different sizes is the same as that of the flat steel plate with the same steel type except for the furnace time and the heat preservation time, and the furnace time and the heat preservation time depend on the minimum plate thickness Ta and the maximum plate thickness Tb:

the furnace time is A Tb, the heat preservation time is B Tb, the unit of min,

wherein A is a furnace time thickness coefficient, and is 1.8-6.0 in unit of min/mm;

b is a heat preservation time thickness coefficient, and the unit min/mm is 1.2-4.0;

b (Tb-Ta) is less than or equal to 40, unit min;

the unit of the minimum plate thickness Tb and the maximum plate thickness Ta is mm;

and cutting the two normalized unsettled difference thick plates to length, and cutting off the length allowance to finally obtain two transversely variable-thickness wide common carbon-manganese steel plates with required dimension specifications.

4. The method for preparing a wide-width common carbon manganese steel plate with a laterally variable thickness according to claim 3, wherein the intermediate blank is directly cast into a steel ingot with the differential thickness surface by a die casting process; or a rectangular blank is obtained by a continuous casting process, and is rolled into an cogging material with the differential thickness surface by longitudinally changing the thickness of the rectangular blank through a wide and thick plate rolling mill.

5. The method for preparing a transversely variable thickness wide plain carbon manganese steel sheet according to claim 3, wherein in step 3), said laminated blanks are combined in multiple lengths in the lengthwise direction or in multiple widths in the widthwise direction to form a laminated blank of a larger single weight in multiple lengths or multiple widths.

Technical Field

The invention relates to a wide and thick steel plate production technology, in particular to a wide and thick common carbon manganese steel plate with a transversely variable thickness and a preparation method thereof.

Background

In industrial production and daily life, the most common wide and thick plate steel is common carbon manganese steel, and the most common delivery state of the common carbon manganese steel is a rolling state or a normalizing state. The common carbon manganese steel wide and thick plate delivered in a rolled state or a normalized state is widely applied to the industries of shipbuilding, bridges, buildings, energy, chemical engineering and the like.

The rolled steel sheet is a steel sheet directly delivered in a rolled state; the normalized steel sheet is a steel sheet which is subjected to a normalization heat treatment as required by the standard for a rolled steel sheet. In actual production, the relevant standards allow the rolled steel sheet to be delivered on "as rolled" basis after being saved by the normalizing process, but do not allow the normalized steel sheet to be delivered on "as normalized" basis without being normalized.

However, whether delivered in rolled state or in normalized state, the common carbon manganese steel wide and thick plates are generally flat plates, i.e. the plate thickness is always constant in the length direction or the width direction of the steel plate, and the cross section of any one of the steel plates perpendicular to the length direction or the width direction is constant to be a rectangle. However, in many cases, the distribution of the load borne by the steel plate along the length direction or the width direction of the steel plate is not constant, but gradually increases or gradually decreases, and therefore, designers often expect that the thickness of the steel plate is not constant, but can be gradually increased or gradually decreased along the length direction or the width direction according to the distribution rule of the load. In other words, the cross section perpendicular to the width or length direction of the steel sheet is not a rectangle, but a right-angled trapezoid or other irregular cross section.

Such a steel sheet with a variable thickness in the longitudinal direction or the width direction is referred to as a differential thickness steel sheet. Among them, the steel sheet having a thickness variable in the rolling direction (i.e., the longitudinal direction) is referred to as a longitudinal differential thickness steel sheet, and the steel sheet having a thickness variable in the direction perpendicular to the rolling direction (i.e., in the width direction) is referred to as a transverse differential thickness steel sheet.

The most direct advantage of using differential thickness steel plates is that the amount of steel used can be saved. However, the saving of the amount of steel used is not the most important motivation of designers to choose a poor-thickness steel plate, and the most important motivation is to reduce the self weight of the steel plate.

Under the condition of the existing wide and thick plate rolling mill, the rolling production process of the longitudinal differential thick steel plate (also called wedge-shaped steel plate in the wide and thick plate industry) is relatively mature. Therefore, the longitudinal differential thickness steel plate has some applications in practical engineering.

In contrast, limited by the existing wide and thick plate rolling technology, the transverse thickness difference common carbon manganese steel plate, especially the transverse thickness difference wide common carbon manganese steel plate with the length of more than 5 meters and the width of more than 2.0 meters, is rarely reported to be applied in practical engineering, and no papers and patents on the manufacturing process and application aspects of the transverse thickness difference wide common carbon manganese steel plate are published. In fact, in practical engineering, the requirements of transverse differential thick steel plates, particularly transverse differential thick and wide common carbon manganese steel plates with the length of more than 5 meters and the width of more than 2.0 meters, are relatively large and even more common than the requirements of longitudinal differential thick steel plates. Typical applications are: the steel plate is used for the differential thickness ship body steel plate on a large ship, the large sluice gate, the differential thickness steel plate on a large bridge and the like. In addition, for steel plates for certain large storage tanks and large wind power generation tower seats, the industrial design requirement of adopting carbon-manganese steel plates with different transverse thicknesses and wide widths is also existed. However, so far, no patent, paper and engineering application report about the production and application of the transverse difference thick and wide carbon manganese steel plate is found at home and abroad.

Disclosure of Invention

The invention aims to provide a wide common carbon-manganese steel plate with transversely variable thickness and a preparation method thereof, wherein the thickness of the steel plate is monotonically and linearly increased or decreased in a sectional manner in the width direction; the steel plate can be economically produced in batch by adopting mature heating, steel rolling and normalizing heat treatment processes through the existing heating, steel rolling and normalizing heat treatment equipment.

In order to achieve the purpose, the technical scheme of the invention is as follows:

the wide-width common carbon-manganese steel plate with the transversely variable thickness is characterized in that the thickness of the steel plate is monotonically and linearly increased or decreased in sections in the width direction; one of the upper surface and the lower surface of the steel plate is a non-horizontal plane which is a slope plane and is inclined in a segmented way, and the other surface of the steel plate is a horizontal plane; the longitudinal section of the steel plate is rectangular, the cross section of the steel plate is a right-angled trapezoid or consists of a plurality of right-angled trapezoids and a rectangle, after one steel plate with the section is rotated by 180 degrees in the horizontal direction and the vertical direction, the slope surface of the steel plate is attached to the slope surface of the other steel plate with the same section, and the two steel plates are overlapped to form a cuboid, namely a overlapped differential thick steel plate; the difference between the maximum plate thickness and the minimum plate thickness of the steel plate is not more than 20mm, the ratio of the maximum plate thickness to the minimum plate thickness is not more than 3:1, and the ratio of the difference between the maximum plate thickness and the minimum plate thickness to the width is not more than 1: 300.

Further, the steel sheet is a rolled steel sheet or a normalized steel sheet.

The invention relates to a preparation method of a wide common carbon-manganese steel plate with transversely variable thickness, which is characterized by comprising the following steps:

1) preparation of superimposed blanks

The device is formed by overlapping two intermediate blanks with the same shape and size, wherein one of the upper surface and the lower surface of the intermediate blank is a non-horizontal plane with a slope surface, namely a slope surface, and the other surface of the intermediate blank is a horizontal plane; the geometric shape of one section of the cross section and the longitudinal section is a right trapezoid or a polygon formed by a plurality of right trapezoids and rectangles, namely a differential thickness surface, and the geometric shape of the other section of the cross section is a rectangle;

the ratio of the thickness Hx of the middle blank at a certain point in the width direction to the thickness Tx of the finished differential thickness steel plate at the corresponding position, namely the compression ratio, is controlled to be 2-6 times, wherein the compression ratio of the thicker side is larger than that of the thinner side; for hot continuous rolling and steckel rolling mills, the width Wp of the intermediate blank is greater than the width W of the finished product differential thick steel plate, and the reversible wide and thick plate rolling mill has no limitation;

2) the slope surfaces of the two intermediate blanks are subjected to leveling and surface cleaning treatment to remove surface defects such as cracks, slag inclusions, pits and the like visible to the naked eye and high-temperature iron scales, so that the finished poor-thickness steel plate is ensured to obtain good surface quality;

3) the peripheries of the two middle blanks are subjected to groove processing, and a slope surface of one of the two middle blanks is coated or covered with a separant; after the other intermediate blank is rotated by 180 degrees in the horizontal direction and the vertical direction respectively, the slope surface of the other intermediate blank is superposed with the slope surface of the intermediate blank coated or covered with the separant to form a superposed blank;

4) carrying out discontinuous welding on the superposed blank along the middle groove gap;

5) manufacture of differential thickness steel plate

Heating, rolling and straightening the superposed blank by the same heating, rolling and straightening processes as those of a flat steel plate of the same steel type to obtain a superposed differential thick steel plate, wherein the thickness Tz of the superposed differential thick steel plate is larger than the sum of the maximum thickness and the minimum thickness of the differential thick steel plate, the width Wz of the superposed differential thick steel plate is larger than the width W of the differential thick steel plate, and the length Lz of the superposed differential thick steel plate is larger than the length L of the differential thick steel plate;

the width allowance of the superposed differential thick steel plate is cut off by adopting hot straightening, cold straightening and trimming, and the lower two layers of steel plates are separated into two non-sized differential thick plates;

if the differential thick steel plate is a rolled delivered steel plate, directly cutting the two unsettled differential thick plates to length, and cutting off the length allowance to finally obtain two transversely variable-thickness wide common carbon manganese steel plates with required dimension and specification;

if the differential thick steel plate is a steel plate delivered in a normalized state, the two non-sized differential thick plates are sent into a normalizing heat treatment furnace for normalizing treatment; the normalizing process of the two steel plates with the different sizes is the same as that of the flat steel plate with the same steel type except for the furnace time and the heat preservation time, and the furnace time and the heat preservation time depend on the minimum plate thickness Ta and the maximum plate thickness Tb:

the furnace time is A Tb, the heat preservation time is B Tb, the unit of min,

wherein A is a furnace time thickness coefficient, and is 1.8-6.0 in unit of min/mm;

b is a heat preservation time thickness coefficient, and the unit min/mm is 1.2-4.0;

b (Tb-Ta) is less than or equal to 40, unit min;

the unit of the minimum plate thickness Tb and the maximum plate thickness Ta is mm;

and cutting the two normalized unsettled difference thick plates to length, and cutting off the length allowance to finally obtain two transversely variable-thickness wide common carbon-manganese steel plates with required dimension specifications.

Preferably, the intermediate blank is directly cast into a steel ingot with the differential thickness surface by adopting a die casting process; or a rectangular blank is obtained by a continuous casting process, and is rolled into an cogging material with the differential thickness surface by longitudinally changing the thickness of the rectangular blank through a wide and thick plate rolling mill.

In step 3), the laminated material is combined in multiple scales in the longitudinal direction or in multiple widths in the width direction to form a laminated material having a larger unit weight of multiple scales or multiple widths.

The invention has the beneficial effects that:

1) the invention uses the existing heating, steel rolling, straightening, heat treatment, lifting and other equipment, such as the existing continuous heating furnace, wide and thick plate rolling mill, hot straightening machine, normalizing heat treatment furnace, magnetic disc lifting and other equipment, and adopts the mature heating, rolling, straightening and normalizing heat treatment process, thereby being capable of economically producing wide steel plates with transversely variable thickness, namely wide steel plates with transversely different thicknesses or short-term different-thickness steel plates in batches.

2) The width and the length of the differential thick steel plate can reach the normal range of a flat wide steel plate, for example: the maximum width can reach 4800mm, and the maximum length can reach 25000 mm.

3) The sum Tz of the maximum thickness Tb and the minimum thickness Ta of the differential thick steel plate can reach the normal thickness range of a flat wide steel plate.

4) The cross section of the differential thickness steel plate can be a single trapezoid, and can also be a polygon formed by a plurality of right-angle trapezoids and rectangles, so that the thickness change of the steel plate in the width direction can be one slope, and can also be a plurality of slopes.

5) The thickness difference of the differential thick steel plate is not more than 20mm in the whole plate range, the ratio of the thickness difference is not more than 3:1, and the differential thickness ratio is not more than 1: 300.

Drawings

FIG. 1 is a schematic structural diagram of a transverse differential thickness wide width common carbon manganese steel plate according to the present invention; in the figure, 1 is a transverse differential thickness wide width common carbon manganese steel plate, 11 is a differential thickness surface, 12 is a slope surface, W is the width of the differential thickness steel plate, W1, W2 and W3 … … are the width of each width section respectively, L is the length of the differential thickness steel plate, Ta is the minimum thickness of the steel plate, Tb is the maximum thickness of the steel plate, T1 and T2 … … are the maximum plate thickness or the minimum plate thickness of each width section of the steel plate respectively, and Tx is the thickness of a certain position of the steel plate. After the steel plate with the differential surface 11 is rotated by 180 ° in each of the horizontal and vertical directions, the steel plate may be stacked with another steel plate with the same differential surface to form a rectangular parallelepiped, and the rectangular parallelepiped may be formed to have a height of Ta + Tb and a width of W.

Fig. 2 is a schematic view of a single overlapped differential thickness steel plate obtained by stacking two differential thickness steel plates according to the present invention, wherein 1 and 2 are the two differential thickness steel plates, respectively, and 11 and 21 are the differential thickness surfaces of the two differential thickness steel plates, respectively. After one of the two steel plates rotates 180 degrees in the horizontal direction and the vertical direction, the slope surface of the two steel plates can be attached to the slope surface of the other steel plate with the same section, and the two steel plates are overlapped to form a cuboid, namely a overlapped differential thickness steel plate; wz and Lz are respectively the width and length of the superposition difference thick steel plate, Tz is the thickness of the superposition difference thick steel plate, Ta is the minimum thickness of two tension difference thick steel plates, and Tb is the maximum thickness of the two tension difference thick steel plates.

Fig. 3 is a schematic diagram of the intermediate blank of the present invention, in which 3 is the intermediate blank, 32 is a slope surface, 31 is a differential thickness surface, Lp and Wp are respectively the length and width of the intermediate blank, W is the width of the differential thickness steel plate, W0 is the trimming margins on the left and right sides, Wp1, Wp2, Wp3 … … are respectively the width of each width section, Ha is the minimum thickness of the blank, Hb is the maximum thickness of the blank, Hx is the thickness of the blank at a certain width position, and H1, H2, … … are respectively the maximum thickness or the minimum thickness of the blank in each width section. The difference surface 31 is rotated by 180 ° in each of the horizontal direction and the vertical direction and appropriately displaced, and then, the difference surface and the original difference surface 31 may be stacked together to form a rectangle, and the height of the rectangle is Ha + Hb, and the width of the rectangle is Wp.

Fig. 4 is a schematic diagram of two intermediate blanks overlapped and welded into an overlapped blank in the embodiment of the invention, wherein 3 and 4 are the two intermediate blanks after surface treatment and beveling respectively, 5 is a discontinuous welding seam between the two intermediate blanks, 31 and 41 are the difference thickness surfaces of the two intermediate blanks respectively, Ha is the minimum thickness of the intermediate blank, Hb is the maximum thickness of the intermediate blank, and Hp is the thickness of the overlapped blank. Considering the factors of a separating agent and the like, Hp is slightly larger than Ha + Hb, H3x and H4x are the thicknesses of the two middle blanks at a certain width position respectively, and Lp, Wp and Hp are the length, the width and the thickness of the two middle blanks which are welded into a laminated blank in an overlapping mode respectively.

Fig. 5 is a schematic view of a transverse differential thickness steel plate in example 2 of the present invention, in which 1 is the transverse differential thickness steel plate, 11 is a differential thickness surface, 12 denotes a slope surface, W is the width of the differential thickness steel plate, L is the length of the differential thickness steel plate, Ta is the minimum thickness of the steel plate, Tb is the maximum thickness of the steel plate, and Tx is the thickness of the steel plate at a certain width position.

Fig. 6 is a schematic view of an intermediate material in example 2 of the present invention, in which 3 is the intermediate material, 32 is a slope surface, 31 is a difference thickness surface, Lp and Wp are the length and width of the intermediate material, W is the width of the difference thickness steel plate, and W0 is the trimming margins on the left and right sides. Ha is the minimum thickness of the blank, Hb is the maximum thickness of the blank, and Hx is the thickness of the blank at a certain width position. The difference surface 31 is rotated by 180 ° in each of the horizontal direction and the vertical direction and appropriately displaced, and then, the difference surface and the original difference surface 31 may be stacked together to form a rectangle, and the height of the rectangle is Ha + Hb, and the width of the rectangle is Wp.

Fig. 7 is a schematic diagram of a superimposed blank in embodiment 2 of the present invention, in which 3, 4 are two intermediate blanks after surface treatment and beveling, 5 is a welding seam welded discontinuously along peripheral bevels of the two intermediate blanks, 31, 41 are differential thickness surfaces of the two intermediate blanks, Ha is the minimum thickness of the intermediate blank, Hb is the maximum thickness of the intermediate blank, Hx is the thickness of the intermediate blank at a certain width position, and Lp, Wp, and Hp are the length, width, and thickness of the superimposed blank obtained by superimposing and welding the two intermediate blanks.

Fig. 8 is a schematic view of a single overlapped differential thick steel plate formed by overlapping two transverse differential thick steel plates in example 2 of the present invention, in which 1 and 2 are the two transverse differential thick steel plates, respectively, and 11 and 21 are the differential thick surfaces of the right trapezoid of the two steel plates, respectively. After one of the two steel plates rotates 180 degrees in the horizontal direction and the vertical direction, the slope surface of the two steel plates can be attached to the slope surface of the other steel plate with the same section, and the two steel plates are overlapped to form a cuboid, namely a overlapped differential thickness steel plate; and overlapping the differential thickness steel plates, wherein Wz, Lz and Tz are respectively the width, length and thickness of the overlapping differential thickness steel plates, Ta is respectively the minimum thickness of the two differential thickness steel plates, Tb is respectively the maximum thickness of the two differential thickness steel plates, and T1x and T2x are respectively the thicknesses of the two steel plates at certain width positions.

Detailed Description

The present invention will be further described with reference to the following examples and accompanying drawings.