阅读说明：本技术 一种适用于步进式加热炉的圆形连铸坯的预处理方法 (Pretreatment method of circular continuous casting billet suitable for walking beam furnace ) 是由 吴剑 王凌云 高坤 潘明旭 饶金元 邓小利 周杰 余攀 卢荣凤 于 2021-06-25 设计创作，主要内容包括：本发明提供一种适用于步进式加热炉的圆形连铸坯的预处理方法,所述预处理方法包括以下步骤：步骤S1,根据圆形连铸坯的尺寸确定圆形连铸坯的压扁参数；步骤S2,根据压扁参数对圆形连铸坯进行压扁操作,压扁后的连铸坯包括两个相对的压扁部,所述压扁部的宽度不小于130mm。本发明圆形连铸坯的预处理方法可以实现圆形连铸坯能够在现有步进式加热炉内稳步前进。(The invention provides a pretreatment method of a circular continuous casting billet suitable for a stepping heating furnace, which comprises the following steps: step S1, determining the flattening parameters of the circular continuous casting billet according to the size of the circular continuous casting billet; and step S2, performing flattening operation on the round continuous casting billet according to the flattening parameters, wherein the flattened continuous casting billet comprises two opposite flattening parts, and the width of each flattening part is not less than 130 mm. The pretreatment method of the circular continuous casting billet can realize that the circular continuous casting billet can stably advance in the traditional stepping heating furnace.)

1. A pretreatment method of a circular continuous casting billet suitable for a walking beam furnace is characterized by comprising the following steps:

step S1, determining target flattening parameters of the circular continuous casting billet according to the size of the circular continuous casting billet;

and step S2, performing flattening operation on the round continuous casting billet according to the target flattening parameters, wherein the flattened continuous casting billet comprises two opposite flattening parts, and the width of each flattening part is not less than 130 mm.

2. The method for pretreating a round slab for use in a walking beam furnace according to claim 1, wherein the target flattening parameters in step S1 include a target flattening reduction, and step S1 specifically comprises:

step S11, calculating the maximum rolling reduction according to the stability of the regular triangle, and then determining the minimum rolling reduction according to the diameter of the circular continuous casting billet and the minimum width of the flattening part;

and step S12, determining a target flattening reduction amount according to the maximum reduction amount and the minimum reduction amount, wherein the target flattening reduction amount is between the maximum reduction amount and the minimum reduction amount.

3. The method for pretreating a circular slab for use in a walking beam furnace according to claim 2, wherein said target rolling reduction is increased as the diameter of said circular slab is increased.

4. The method for pretreating a round billet suited for use in a walking beam furnace according to claim 2, wherein the diameter of the round billet is defined as 2R and the maximum reduction is defined as D_maxThe minimum rolling reduction is D_minIn units of mm, then D_max＝2R-3^0.5R，D_min＝2R-2×(R²-65²)^0.5。

5. The method for pretreating a round cast slab in a walking beam furnace according to any one of claims 2 to 4, wherein the round cast slab is flattened by a withdrawal straightening machine in step S2, wherein the withdrawal straightening machine is provided with upper and lower opposed lower rolls, the upper and lower opposed lower rolls are flat rolls, and the step S2 specifically comprises:

and setting the distance between the press rolls on the upper side and the lower side of the withdrawal and straightening machine according to the target flattening reduction, and controlling the press rolls on the upper side and the lower side of the withdrawal and straightening machine to be close to each other so as to flatten the round continuous casting billets.

6. The method of pretreating a round slab for use in a walking beam furnace according to claim 5, wherein the withdrawal speed of the withdrawal straightening machine is kept constant during the flattening operation in step S2.

7. The method of pretreating a round continuous cast slab for a walking-beam furnace according to claim 6, wherein the withdrawal speed of the withdrawal straightening machine in step S2 is 0.4 to 0.5 m/min.

8. The method for pretreating a round continuous cast slab suitable for a walking beam furnace according to claim 5, wherein the withdrawal and straightening unit is provided in a plurality of stages in step S2, and the step S2 specifically comprises:

target flattening reduction amounts are evenly distributed according to the number of the withdrawal straightening machines, and the multiple withdrawal straightening machines sequentially flatten the circular continuous casting billets according to the respective distributed flattening reduction amounts.

9. The method for pretreating a circular cast slab suitable for use in a walking beam furnace according to any one of claims 1 to 8, wherein the diameter of said circular cast slab is in the range of 460 to 500 mm.

10. The method for pretreating a circular cast slab suitable for use in a walking beam furnace according to any one of claims 1 to 8, wherein the width of said flattened portion increases as the diameter of said circular cast slab increases.

Technical Field

The invention belongs to the technical field of continuous casting billet production, and particularly relates to a pretreatment method of a circular continuous casting billet suitable for a stepping heating furnace.

Background

At present, the walking beam furnace generally is used for producing square continuous casting billet, if be used for producing circular continuous casting billet, current walking beam furnace mainly has following problem: (1) the space between the heat-resistant blocks in the heating furnace is small, and the round continuous casting billet is easy to roll in the furnace, so that potential safety hazards exist; (2) the supporting facilities of the heating furnace do not have the conditions for feeding the round continuous casting billets: a. the feeding rack is flat and non-serrated, and the round continuous casting billet is easy to roll; b. no clamping groove is arranged on the outer side of the steel inlet and outlet machine, and the round billets are easy to roll when discharged from the furnace. Therefore, the circular continuous casting billet directly produced by the conventional walking beam furnace has safety risk and cannot exert the production capacity of the conventional furnace.

Therefore, there is a need to provide an improved solution to the above-mentioned deficiencies of the prior art.

Disclosure of Invention

The invention aims to provide a pretreatment method of a circular continuous casting billet suitable for a walking beam furnace, which aims to solve the problems that the circular continuous casting billet produced by the existing walking beam furnace has potential safety hazard and cannot exert the production capacity of the heating furnace, so that the circular continuous casting billet can stably move forward in the existing walking beam furnace.

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

a pretreatment method of a circular continuous casting billet suitable for a walking beam furnace comprises the following steps:

step S1, determining target flattening parameters of the circular continuous casting billet according to the size of the circular continuous casting billet;

and step S2, performing flattening operation on the round continuous casting billet according to the target flattening parameters, wherein the flattened continuous casting billet comprises two opposite flattening parts, and the width of each flattening part is not less than 130 mm.

As mentioned above, in the method for pretreating a circular continuous casting slab suitable for a walking beam furnace, as a preferable scheme, the target flattening parameter in step S1 includes a target flattening reduction, and step S1 specifically includes:

step S11, calculating the maximum rolling reduction according to the stability of the regular triangle, and then determining the minimum rolling reduction according to the diameter of the circular continuous casting billet and the minimum width of the flattening part;

and step S12, determining a target flattening reduction amount according to the maximum reduction amount and the minimum reduction amount, wherein the target flattening reduction amount is between the maximum reduction amount and the minimum reduction amount.

In the method for pretreating a round billet suitable for a walking beam furnace as described above, preferably, the target rolling reduction is increased as the diameter of the round billet increases.

The method for pretreating a round cast slab suitable for a walking beam furnace as described above preferably defines the diameter of the round cast slab as 2R and the maximum reduction as D_maxThe minimum rolling reduction is D_minIn units of mm, then D_max＝2R-3^0.5R，D_min＝2R-2×(R²-65²)^0.5。

As a preferable scheme, in step S2, the withdrawal and straightening machine is used to flatten the round continuous casting slab, wherein the withdrawal and straightening machine is provided with upper and lower opposite bottom rollers, the upper and lower bottom rollers are both flat rollers, and step S2 specifically includes:

and setting the distance between the press rolls on the upper side and the lower side of the withdrawal and straightening machine according to the target flattening reduction, and controlling the press rolls on the upper side and the lower side of the withdrawal and straightening machine to be close to each other so as to flatten the round continuous casting billets.

In the method for pretreating a round slab suitable for a walking beam furnace as described above, the withdrawal speed of the withdrawal and straightening unit in step S2 is preferably kept constant during the flattening operation.

More preferably, the pulling speed of the withdrawal and straightening machine is 0.4-0.5 m/min.

As a preferable scheme, in the method for pretreating a circular continuous casting slab applied to a walking beam furnace, the withdrawal and straightening unit is provided with a plurality of units in step S2, and step S2 specifically includes:

target flattening reduction amounts are evenly distributed according to the number of the withdrawal straightening machines, and the multiple withdrawal straightening machines sequentially flatten the circular continuous casting billets according to the respective distributed flattening reduction amounts.

According to the pretreatment method for the circular continuous casting slab suitable for the walking beam furnace, as a preferable scheme, the diameter range of the circular continuous casting slab is 460-500 mm.

In the method for pretreating a round billet suitable for a walking beam furnace as described above, preferably, the width of the flattened part increases as the diameter of the round billet increases.

Has the advantages that:

when the method is used for pretreating the round continuous casting billet, the target flattening parameters of the round continuous casting billet are determined according to the size of the round continuous casting billet, and then the round continuous casting billet is flattened according to the target flattening parameters, the flattened continuous casting billet comprises two opposite flattening parts, and the width of each flattening part is not less than 130mm, so that the flattened continuous casting billet can stably move forward in the conventional stepping heating furnace, and the conventional stepping heating furnace can meet the requirement of batch charging production of the round continuous casting billet.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. Wherein:

FIG. 1 is a schematic structural diagram of a flattened section of a circular continuous casting slab in an embodiment of the invention;

FIG. 2 is a schematic diagram illustrating the principle of calculating the maximum rolling reduction according to the stability of the regular triangle in the embodiment of the present invention.

Reference numbers in the figures: 1. circular continuous casting billets; 2. a flattening part.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments that can be derived by one of ordinary skill in the art from the embodiments given herein are intended to be within the scope of the present invention.

The present invention will be described in detail with reference to examples. It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

As shown in figure 1, when the circular continuous casting billet 1 is pretreated, the target flattening parameters of the circular continuous casting billet 1 are determined according to the size of the circular continuous casting billet 1, and then the circular continuous casting billet 1 is flattened according to the target flattening parameters, the flattened continuous casting billet 1 comprises two opposite flattening parts 2, the flattening parts 2 are provided with flat surfaces, the width of the flattening parts 2 is not less than 130mm, so that the flattened continuous casting billet 1 (with the flattening parts 2) can stably move forward in the existing stepping heating furnace, and the existing stepping heating furnace can meet the batch charging production of the circular continuous casting billet.

The two flattening portions 2 are arranged opposite to each other in the vertical direction and have the same size, and the width of the flattening portion 2 is not less than 130 mm. After putting into step-by-step heating furnace with continuous casting billet 1 after flattening, the roller table contact in flattening portion 2's the surface and the heating furnace because the roller table in the heating furnace is the plane, and flattening portion 2's surface also is the plane, then the contact that the two can be abundant, so alright advance in order to realize continuous casting billet 1 after flattening steadily in current step-by-step heating furnace.

It can be understood that when the width of the flattening part 2 of the round continuous casting billet is not less than 130mm, the flattened round continuous casting billet 1 can be effectively ensured to stably advance in the existing stepping heating furnace, so that the requirement of batch charging production of the round continuous casting billet 1 can be realized by the existing stepping heating furnace. In other words, if the width of the flattening section 2 is less than 130mm, the round continuous cast slab 1 is likely to roll in the heating furnace, which poses a safety hazard and cannot exhibit the productivity of the conventional walking beam furnace.

In the specific embodiment of the present invention, the target flattening parameters in step S1 include a target flattening reduction amount, and step S1 specifically includes:

step S11, calculating the maximum rolling reduction according to the stability of the regular triangle, and then determining the minimum rolling reduction according to the diameter of the circular continuous casting billet 1 and the minimum width of the flattening part 2, wherein the minimum width of the flattening part 2 is the minimum width value which can enable the flattened continuous casting billet 1 to stably advance in the stepping heating furnace;

and step S12, determining a target flattening reduction amount according to the maximum reduction amount and the minimum reduction amount, wherein the target flattening reduction amount is between the maximum reduction amount and the minimum reduction amount.

In the present embodiment, the maximum rolling reduction and the minimum rolling reduction are determined first, and then the target flattening rolling reduction is determined, the target flattening rolling reduction being between the two, wherein the maximum rolling reduction is calculated from the triangle stability, and the minimum rolling reduction is calculated from the diameter of the circular slab 1 and the minimum width of the flattening section 2, or the minimum rolling reduction is determined by gradually reducing the rolling reduction through a practical test. Therefore, the method for determining the target flattening reduction amount is simpler.

In the present invention, the maximum rolling reduction and the minimum rolling reduction are both the sum of the rolling reductions of the two flattened portions 2, that is, the sum of the upper rolling reduction and the lower rolling reduction.

The target flattening reduction of the invention is related to the diameter of the circular continuous casting billet 1, and theoretically, the larger the diameter of the circular continuous casting billet 1 is, the larger the target flattening reduction is, that is, the target flattening reduction is increased along with the diameter increase of the circular continuous casting billet 1.

As shown in FIG. 2, the diameter of the round slab was defined as 2R and the maximum reduction was defined as D_maxThe minimum rolling reduction is D_minThe unit is mm, and the maximum rolling reduction, namely D, can be calculated according to the stability of the regular triangle_max＝2R-3^0.5R, the width of the flattening part of the continuous casting billet can be realized when the width is not less than 130mmThe minimum reduction, namely D, can be calculated by the steady advance in the stepping heating furnace_min＝2R-2×(R²-65²)^0.5。

It should be noted that, as can be seen from the above calculation formula, the maximum reduction is only related to the diameter of the round billet 1, and the maximum reduction increases as the diameter of the round billet 1 increases. The minimum reduction is related to the minimum width of the flattening section 2 and the diameter of the round billet 1, and generally, the minimum width of the flattening section 2 is constant, so the minimum reduction varies with the diameter of the round billet 1.

In the embodiment of the invention, when the radius R of the circular continuous casting billet is 230mm, the maximum reduction D can be calculated by the calculation formula_max60mm and a minimum rolling reduction of 20 mm.

In a specific embodiment of the present invention, in step S2, a withdrawal and straightening machine is used to flatten a round continuous casting slab, wherein the withdrawal and straightening machine is provided with two opposite bottom rollers at the upper and lower sides, and the bottom rollers at the upper and lower sides are both flat rollers, and step S2 specifically includes:

and setting the distance between the press rolls on the upper side and the lower side of the withdrawal and straightening machine according to the target flattening reduction, and controlling the press rolls on the upper side and the lower side of the withdrawal and straightening machine to be close to each other so as to flatten the round continuous casting billets.

The method adopts a withdrawal and straightening machine to carry out flattening operation on a smelted circular continuous casting billet 1, wherein the withdrawal and straightening machine is provided with lower press rolls with opposite upper and lower sides, and the lower press rolls are flat rolls, when in flattening operation, the circular continuous casting billet 1 is placed between the lower press rolls on the two sides, the distance between the lower press rolls on the upper and lower sides of the withdrawal and straightening machine is set according to the target flattening reduction, and the lower press rolls on the upper and lower sides are controlled to be close to each other so as to carry out flattening operation on the circular continuous casting billet 1. Thus, the two side flattening parts 2 which are oppositely arranged can be obtained after the round continuous casting billet 1 is flattened, and the surfaces of the flattening parts 2 at the two sides are both planes.

It should be noted that, during the flattening operation, the rolling reduction of the round slab 1 by the two side rolls is kept uniform, and the two flattened portions 2 formed in this way have the same size.

In the embodiment of the invention, in order to ensure that the surface of the finally formed flattening part 2 is flat and uniform, the withdrawal speed of the withdrawal and straightening machine is kept constant in the flattening process, namely the withdrawal and straightening machine is kept to run at a constant speed.

In the preferred embodiment of the invention, the pulling speed of the withdrawal and straightening machine is 0.4-0.5 m/min (such as 0.4m/min, 0.41m/min, 0.42m/min, 0.43m/min, 0.44m/min, 0.45m/min, 0.46m/min, 0.47m/min, 0.48m/min, 0.49m/min or 0.5m/min), and the pulling speed range is set, so that the surface of the finally formed flattened part 2 can be more effectively ensured to be flat and uniform.

In the embodiment of the present invention, the withdrawal and straightening unit is set to have a plurality of units in step S2, and step S2 specifically includes:

target flattening reduction amounts are evenly distributed according to the number of the withdrawal straightening machines, and the multiple withdrawal straightening machines sequentially flatten the circular continuous casting billets 1 according to the respective distributed flattening reduction amounts.

Adopt many withdrawal and straightening machines to flatten operation in proper order to circular continuous casting billet 1, can guarantee to flatten the accuracy of operation, can improve simultaneously and flatten the degree of difficulty of operation, especially the decrement that the great circular continuous casting billet of specification needs is great, if only adopt one withdrawal and straightening machine then to flatten the operation degree of difficulty great, and consuming time longer, if adopt many withdrawal and straightening machines to flatten the operation to it in proper order, then to flatten the operation easier, consuming time less. When a plurality of withdrawal and straightening machines are adopted, the maximum rolling reduction and the minimum rolling reduction are calculated by referring to the method, and then the target flattening rolling reduction is determined according to the maximum rolling reduction and the minimum rolling reduction, wherein the target flattening rolling reduction is between the maximum rolling reduction and the minimum rolling reduction. And finally, evenly distributing the determined target flattening reduction amount according to the number of the withdrawal straightening machines, and sequentially flattening the circular continuous casting billets by the multiple withdrawal straightening machines according to the respectively distributed flattening reduction amounts during flattening operation.

The applicable diameter range of the circular continuous casting billet 1 is 460-500 mm (such as 460mm, 470mm, 480mm, 490mm or 500mm), and correspondingly, the minimum width of the flattening part 2 is 130-140 mm.

The target flattening reduction amount and the width of the flattening part 2 have a direct relation and can be converted with each other through triangle calculation, wherein the width of the flattening part 2 is related to the smoothness of the flattened circular continuous casting billet 1 when the circular continuous casting billet 1 advances in the stepping heating furnace, the optimal width of the flattening part 2 is obtained through a step-by-step test, and the width of the flattening part 2 is not less than 130 mm.

In the same way, the width of the flattened part 2 according to the invention is related to the diameter of the round billet 1, and theoretically, the larger the diameter of the round billet 1, the larger the width of the flattened part 2, i.e. the width of the flattened part 2 increases as the diameter of the round billet 1 increases.

The method for pretreating a round billet according to the present invention will be described in detail below by way of specific examples.

Example 1

The diameter of the circular continuous casting billet is 460mm in the embodiment, the withdrawal and straightening machine is adopted to carry out flattening operation on the circular continuous casting billet, the flattening reduction amount can be calculated to be 60mm according to the stability of the regular triangle, and then the minimum reduction amount is determined to be 20mm according to the diameter of the circular continuous casting billet and the minimum width of the flattening part.

The drawing speed of the withdrawal and straightening machine is kept constant in the flattening operation process and is set to be 0.46m/min, and the width of a flattening part is 130mm after flattening.

Put into marching type heating furnace with the continuous casting billet after flattening for the roll table contact of flattening portion and heating furnace, through experimental, the continuous casting billet after flattening can be in the steady advance of marching type heating furnace, satisfies the production demand.

Comparative example 1

In the embodiment, the diameter of the round continuous casting billet is 460mm, the withdrawal and straightening machine is used for carrying out flattening operation on the round continuous casting billet, the withdrawal speed of the withdrawal and straightening machine is ensured to be constant in the flattening operation process and is set to be 0.46m/min, and the width of the flattened part is 110mm after flattening.

Put into marching type heating furnace with the continuous casting billet after flattening for the roll table contact of flattening portion and heating furnace, through experimental, the continuous casting billet after flattening can easily take place to roll in marching type heating furnace, unsatisfied production demand.

Comparative example 2

In the embodiment, the diameter of the round continuous casting billet is 460mm, the withdrawal and straightening machine is used for carrying out flattening operation on the round continuous casting billet, the withdrawal speed of the withdrawal and straightening machine is ensured to be constant in the flattening operation process and is set to be 0.46m/min, and the width of the flattened part is 120mm after flattening.

Put into marching type heating furnace with the continuous casting billet after flattening for the roll table contact of flattening portion and heating furnace, through experimental, the continuous casting billet after flattening can easily take place to roll in marching type heating furnace, unsatisfied production demand.

Example 2

The diameter of the circular continuous casting billet is 480mm in the embodiment, the withdrawal and straightening machine is adopted to carry out flattening operation on the circular continuous casting billet, the flattening reduction amount can be 65mm according to the stability of the regular triangle, and then the minimum reduction amount is 18mm according to the diameter of the circular continuous casting billet and the minimum width of the flattening part.

The drawing speed of the withdrawal and straightening machine is kept constant in the flattening operation process and is set to be 0.46m/min, and the width of the flattened part is 135mm after flattening.

Put into marching type heating furnace with the continuous casting billet after flattening for the roll table contact of flattening portion and heating furnace, through experimental, the continuous casting billet after flattening can be in the steady advance of marching type heating furnace, satisfies the production demand.

Example 3

The diameter of circular continuous casting billet is 500mm in this embodiment, adopts the withdrawal and straightening machine to flatten the operation to circular continuous casting billet, and its flattening rolling reduction can calculate the maximum rolling reduction according to regular triangle stability and be 68mm, later through confirming its minimum rolling reduction to be 18mm according to the diameter of circular continuous casting billet and the minimum width of flattening portion.

The drawing speed of the withdrawal and straightening machine is kept constant in the flattening operation process and is set to be 0.46m/min, and the width of the flattened part is 140mm after flattening.

Put into marching type heating furnace with the continuous casting billet after flattening for the roll table contact of flattening portion and heating furnace, through experimental, the continuous casting billet after flattening can be in the steady advance of marching type heating furnace, satisfies the production demand.

In summary, the following steps: according to the invention, when the circular continuous casting billet 1 is pretreated, the target flattening reduction of the circular continuous casting billet 1 is determined according to the diameter of the circular continuous casting billet 1, and then the circular continuous casting billet is flattened according to the target flattening reduction, the flattened continuous casting billet 1 comprises two opposite flattening parts 2, and the width of the flattening part 2 is not less than 130mm, so that the flattened continuous casting billet 1 can stably move forward in the existing stepping heating furnace, and the requirement of batch charging production of the circular continuous casting billet 1 is met by the existing stepping heating furnace.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.