Titanium plate rolling method

Abstract

The application provides a titanium plate rolling method, comprising the following steps: (1) using a slab to carry out heating by adopting a pulse heating furnace; (2) adopting a constant reduction method to control rolling in a high-temperature section for the heated slab, and adopting a reduction decrement method to control rolling in a low-temperature section for the slab. The application uses a process strategy of temperature acquisition and fast rolling, the slab is transported to a rolling mill at the fastest roller way speed after being heated to carry out rolling, the temperature is controlled in the whole process to control rolling in an alpha single phase region, the constant reduction method is adopted to control rolling in the high-temperature section, the rolling force fluctuation is small in this stage, and the plate shape is well controlled; the reduction decrement method is adopted to control rolling in the low-temperature section, the rolling temperature is controlled in the process requirement range, the titanium plate shape is ensured, and the surface cracks of the plate are greatly reduced.

Description

Technical Field

[0001] This invention belongs to the field of titanium plate technology and relates to a method for rolling titanium plates. Background Technology

[0002] Titanium and titanium alloy plates, due to their low density, high specific strength, good toughness, strong corrosion resistance, and high temperature resistance, have been widely used in aerospace, machinery manufacturing, weapons production, chemical and medical fields. With the rapid development of modern technology, the titanium industry has entered a new normal, and national defense and technological development require a large amount of titanium plates to meet the demand.

[0003] However, domestic titanium plate production started relatively late, with incomplete mastery of production technology, outdated rolling equipment, low degree of process automation, and low production capacity and output. In particular, there are many technical difficulties in the titanium plate rolling process. Unlike the rolling of ordinary metal sheets, titanium plates have poor thermal conductivity and a narrow rolling temperature window. If the initial rolling temperature is too high or the rolling deformation is too large, the temperature in the center of the rolled piece will rise sharply, even to the point of boiling over. β In the titanium plate rolling process, the already fragmented grains tend to grow rapidly, causing structural defects and affecting the material's mechanical properties. If the initial rolling temperature is low, the mill load is high, and there are more edge and surface cracks in the plate. Furthermore, due to the large temperature difference between the upper and lower surfaces during titanium plate rolling, the upper surface generally elongates more than the lower surface, making the plate prone to buckling. During the biting stage, the plate easily impacts the work roll guard plate, causing scratches on the lower surface and even roll entanglement. When the surface temperature drops below the process window, cracks easily form on both the upper and lower surfaces, requiring more customer grinding, reducing the yield of titanium plates, and increasing production costs. All of these factors increase the difficulty and cost of titanium plate rolling, and also place higher demands on titanium plate rolling processes. Summary of the Invention

[0004] The purpose of this invention is to provide a method for rolling titanium plates, addressing the problems existing in the prior art.

[0005] Therefore, the present invention adopts the following technical solution:

[0006] A method for rolling titanium plates includes the following steps:

[0007] (1) The slab is heated to 820-840℃ using a pulse heating furnace for 270-290 minutes;

[0008] (2) The heated slab is rolled using the constant reduction method in the high-temperature section and the slab is rolled using the decreasing reduction method in the low-temperature section.

[0009] Furthermore, the temperature of the high-temperature section in step (1) is 720-840℃.

[0010] Furthermore, in step (1), the constant reduction rolling process is carried out in 6 passes with an initial rolling temperature of 770-790℃ and a reduction rate of 9-11% per pass.

[0011] Furthermore, the low temperature range in step (2) is below 700°C.

[0012] Furthermore, in step (2), the rolling process is carried out in 8 passes with a final rolling temperature of 670-690℃. The reduction rate of the first pass is 9-11%, and the reduction rate of the remaining passes is reduced by 1% for each pass.

[0013] Furthermore, in step (2), the mill guard plate is chamfered before rolling.

[0014] The beneficial effects of this invention are as follows: by using a rapid rolling process strategy, the slab is heated and then transported to the rolling mill at the fastest roller speed for rolling. The temperature is controlled within the α single-phase region during the entire process. In the high-temperature section, the constant reduction method is used to control the rolling, which results in small fluctuations in rolling force and good control of the plate shape. In the low-temperature section, the reduction method is used to control the rolling, keeping the rolling temperature within the process requirements. This ensures the shape of the titanium plate and greatly reduces surface cracks. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of the protective plate after the edge is chamfered according to the present invention;

[0016] In the diagram, 1-lower work roll guard plate, 2-side. Detailed Implementation

[0017] The present invention will be described in detail below with reference to embodiments:

[0018] A method for rolling titanium plates includes the following steps:

[0019] (1) The slab is heated in a pulse heating furnace at 820-840°C for 270-290 minutes. In this embodiment, it is heated to 820°C for 270 minutes. The composition and percentage of the substances contained in the slab are consistent with those of conventional titanium plates. Compared with continuous combustion, pulse combustion control technology heating furnace has the advantages of precise temperature control and low oxidation loss. At the same time, it reduces the heating temperature at each stage and reduces the time in the furnace to reduce the generation of oxidation loss.

[0020] (2) The heated slab is quickly transported to the rolling mill for rolling, and the temperature is controlled at [temperature range] throughout the process. αSingle-phase controlled rolling is used. The slab is rolled using the constant reduction method in the high-temperature section, with a temperature of 720-840℃. Specifically, the constant reduction method involves 6 passes, with an initial rolling temperature of 770-790℃ (780℃ in this embodiment). The reduction rate for each pass is 9-11% (10% in this embodiment). During this stage, the rolling force fluctuation is small, and the slab shape is well controlled. In the low-temperature section, the slab is rolled using the decreasing reduction method (below 700℃). Specifically, the decreasing reduction method involves 8 passes, with a final rolling temperature of 670-690℃ (680℃ in this embodiment). The reduction rate for the first pass is 9-11% (10% in this embodiment), and the reduction rate for each subsequent pass is reduced by 1%, resulting in a reduction rate of 3% for the last pass. By controlling the rolling temperature within the process requirements, the slab shape of the titanium plate is ensured, and surface cracks are significantly reduced.

[0021] Furthermore, during the rolling process, the titanium plate will experience a buckling phenomenon. During the biting stage, it will impact and rub against the edge 2 of the lower work roll guard plate 1 of the rolling mill. Because the edge 2 of the lower work roll guard plate 1 has sharp edges, the titanium plate will have deep scratches, resulting in severe cracks and wax buildup on the lower surface of the finished product. Therefore, edge 2 needs to be chamfered and rounded (e.g., ...). Figure 1 As shown in the figure, this effectively avoids rigid impact between the rolled piece and the guard plate, and improves the surface quality of the titanium plate.

Claims

1. A method for rolling titanium plates, characterized in that, Includes the following steps: (1) The slab is heated to 820-840℃ using a pulse heating furnace for 270-290 minutes; (2) The heated slab is rolled in the high-temperature section using the constant reduction method, and the slab is rolled in the low-temperature section using the decreasing reduction method. The temperature of the high-temperature section is 720-840℃. The constant reduction method is rolled in 6 passes with an initial rolling temperature of 770-790℃ and a reduction rate of 9-11% per pass. The temperature of the low-temperature section is below 700℃. The decreasing reduction method is rolled in 8 passes with a final rolling temperature of 670-690℃. The reduction rate of the first pass is 9-11%, and the reduction rate of each of the remaining passes is reduced by 1%. The mill guard plate is chamfered before rolling.

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