阅读说明：本技术 一种棒材轧后穿水工艺 (Water penetrating technology after bar rolling ) 是由 杨秀灯 魏恒露 王晓峰 陈秋叶 高俊 吴振伟 张羽 周沈 于 2021-07-20 设计创作，主要内容包括：本发明提供一种棒材轧后穿水工艺,具有以下有益效果：冷却总水管通过快切阀与第一穿水管连接,通过流量调节阀与第二穿水管连接；流量调节阀用于调节第一穿水管与第二穿水管的流量；快切阀和流量调节阀的设置,调节棒材头部经过穿水管的温度,从而使棒材头部温度与其余部位的温度趋于一致,解决了棒材头部出现宏观穿水亮环现象,使棒材成品头部宏观金相满足GB/T1499.2-2018《钢筋混凝土用钢-第二部分：热轧带肋钢筋》质量要求。(The invention provides a post-rolling water-penetrating process for bars, which has the following beneficial effects: the cooling water main is connected with a first water through pipe through a quick-cutting valve and connected with a second water through pipe through a flow regulating valve; the flow regulating valve is used for regulating the flow of the first water passing pipe and the second water passing pipe; the setting of fast valve and flow control valve adjusts the temperature of rod head through the water pipe to make rod head temperature and the temperature of other positions tend to unanimous, solved the macroscopical bright ring phenomenon of wearing water that appears in rod head, make rod finished product head macroscopical metallography satisfy GB/T1499.2-2018 steel for reinforced concrete-second part: hot rolled ribbed bar "quality requirement.)

1. A post-rolling water-penetrating process for bars is characterized by comprising the following steps:

s1, feeding the bar into a heating furnace (1) for heating and then feeding the bar into a roughing mill group (2);

s2, allowing the bar to pass through the rough rolling mill group (2), shearing the head by the first flying shear (3), and then sequentially entering the intermediate rolling mill group (4) and the finishing rolling mill group (5);

s3, when the bar enters the end unit of the finishing mill unit (5), closing the quick-cutting valve (7) of the first water passing pipe (6) and stopping the first water passing pipe (6) from providing cooling water;

s4, after delaying for a period of time, opening the quick-cutting valve (7), wherein the head of the bar penetrates out of the first water penetrating pipe (6) and enters a second water penetrating pipe (8), and the second water penetrating pipe (8) is provided with a normally-open flow regulating valve (9);

s5, cutting the bar into a plurality of sections with equal length through a second flying shear (10) after the bar penetrates out of the second water penetrating pipe (8);

s6, casting the bar to a cooling bed (11) under the action of a conveying roller way and a steel casting device;

s7, cooling the bar by the cooling bed (11), and then cutting the bar into a plurality of sections with the length meeting the requirement in a cold shearing machine (12);

and S8, sequentially collecting, bundling, weighing and listing the rods and then warehousing.

Technical Field

The invention relates to the technical field of steel rolling, in particular to a post-rolling water-penetrating process for a bar.

Background

At present, straight screw rods are generally produced by a post-rolling water-through cooling control process, the process can improve the mechanical property of the rods and provide space for reducing the cost of steel alloy, namely, after the heating rods are led out from finished product holes through a rough rolling unit, a middle rolling unit and a finishing rolling unit, the heating rods firstly enter a water-through device for cooling control, and then enter a large cooling bed through equipment such as a guide groove, a multiple length shear, steel throwing and the like. The temperature of the finished product is about 1040 +/-30 ℃ before entering a water passing device, the temperature of the finished product is about 700 +/-30 ℃ after water passing cooling, the temperature of the finished product is raised to 930 +/-30 ℃ in the process of throwing steel to a cooling bed through a conveying roller way, and the sampling mechanical property of the intermediate finished product of the bar meets the national standard requirement. But the temperature of the cast steel entering the head of the bar finished product of the large cooling bed is only 800 +/-20 ℃ and is 110 ℃ lower than the temperature of the intermediate finished product of the bar, the head of the bar is sampled, pickled and ground at 30 centimeters, the visual observation of the end part shows that a circle of water-through bright ring with the thickness of 50um which is obviously different from the closed color of the center of the bar is arranged outside the end part, the microscopic metallographic detection shows that the edge of the end part of the bar has a bright white area which is ferrite and pearlite with finer grains, and the ferrite structure is more than that of the intermediate matrix of the bar and is a non-water-through tempered martensite structure. According to GB/T1499.2-2018 Steel for reinforced concrete-second part: according to the item B1.5 in the appendix of the file appendix of the hot-rolled ribbed steel bar, if the macroscopic metallographic phase of a deformed steel bar sample has a closed ring with a cross section base circle periphery obviously different from the contrast of an internal area, the deformed steel bar is judged to be a non-hot-rolled steel bar, and therefore the key for ensuring that the metallographic phase of a finished product meets the quality requirement is to solve the problem that the difference between the head temperature and the intermediate temperature of the finished product bar is large.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the technical problem of large temperature difference between the head part and the middle part of the traditional bar after water cooling is solved.

The invention provides a post-rolling water-penetrating process for bars, which comprises the following steps:

s1, feeding the bar into a heating furnace for heating and then feeding the bar into a roughing mill group;

s2, allowing the bar to pass through the rough rolling mill set, passing through a first flying shear shearing head, and then sequentially entering a medium rolling mill set and a finishing rolling mill set;

s3, when the bar enters the tail end unit of the finishing mill unit, closing a quick-cutting valve of a first water passing pipe, and stopping the first water passing pipe from providing cooling water;

s4, after delaying for a period of time, opening the quick-cutting valve, wherein the head of the bar penetrates out of the first water penetrating pipe and enters a second water penetrating pipe, and the second water penetrating pipe is provided with a normally open flow regulating valve;

s5, cutting the bar into a plurality of sections with equal length through a second flying shear after the bar penetrates out of the second water penetrating pipe;

s6, casting the bar to a cooling bed under the action of a conveying roller way and a steel casting device;

s7, cooling the bar by the cooling bed, and then cutting the bar into a plurality of sections with the length meeting the requirement in a cold shearing machine;

and S8, sequentially collecting, bundling, weighing and listing the rods and then warehousing.

The roughing mill group, the intermediate mill group and the finishing mill group are used for sequentially increasing the forming precision of rolled bars; the cooling water main is connected with a first water through pipe through a quick-cutting valve and connected with a second water through pipe through a flow regulating valve; the flow regulating valve is used for regulating the flow of the first water passing pipe and the second water passing pipe; the quick-cut valve is a three-way valve, and when the first water passing pipe needs to stop supplying water, the three-way valve leads out cooling water originally supplied to the first water passing pipe, so that the flow of the second water passing pipe is kept stable; the setting of fast valve and flow control valve adjusts the temperature of rod head through the water pipe to make rod head temperature and the temperature of other positions tend to unanimous, solved the macroscopical bright ring phenomenon of wearing water that appears in rod head, make rod finished product head macroscopical metallography satisfy GB/T1499.2-2018 steel for reinforced concrete-second part: hot rolled ribbed bar "quality requirement.

Drawings

The invention is further illustrated with reference to the following figures and examples.

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a detail view at A of FIG. 1;

in the figure: 1. heating furnace; 2. a roughing mill train; 3. a first flying shear; 4. a medium mill group; 5. a finishing mill group; 6. a first water penetration pipe; 7. a quick-cut valve; 8. a second water penetration pipe; 9. a flow regulating valve; 10. a second flying shear; 11. cooling the bed; 12. a cold shearing machine.

Detailed Description

The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic views illustrating only the basic structure of the present invention in a schematic manner, and thus show only the constitution related to the present invention.

As shown in figures 1-2, the invention relates to a water passing process after bar rolling, which comprises the following steps:

s1, feeding the bar into a heating furnace 1, heating to 1050 +/-30 ℃, discharging and feeding the bar into a roughing mill group 2;

s2, allowing the bar to pass through the rough rolling mill group 2, shearing the head by 30cm through the first flying shear 3, and then sequentially entering the intermediate rolling mill group 4 and the finishing rolling mill group 5;

s3, when the bar enters the end unit of the finishing mill unit 5, closing the quick-cutting valve 7 of the first water passing pipe 6, and stopping the first water passing pipe 6 from providing cooling water; the quick-cut valve 7 is a pneumatic three-way valve which is communicated with the cooling main water pipe and the first water through pipe 6 in a conventional state; the temperature of the bar just after the bar is taken out of the finishing mill group 5 is 1040 +/-30 ℃;

s4, after delaying for 420ms, opening the pneumatic three-way valve, wherein the head of the rod penetrates out of the first water penetrating pipe 6 by one meter and enters the second water penetrating pipe 8, and the second water penetrating pipe 8 is provided with a normally open flow regulating valve 9; rolling in the final stand of the finishing train 5The speed is 13.5m/s, the distance from the frame at the tail end of the finishing mill group 5 to the first water penetrating pipe 6 is 4.5m, and the lengths of the first water penetrating pipe 6 and the second water penetrating pipe 8 are 3.8 m; the flow of the cooling water main pipe is 310m³The flow of the first water passing pipe 6 is 180m under the action of the flow regulating valve 9 under the pressure of 1.3Mpa³H, the normal open flow of the second water passing pipe 8 is 130m³/h；

S5, when the bar passes through the second water passing pipe 8, the temperature of the bar is 700 +/-30 ℃, the bar passes through the annular cooling device, the annular cooling device is provided with a plurality of pipelines which are arranged in parallel, each pipeline is formed by coaxially arranging a plurality of pipes at intervals, and when the bar passes through the pipelines, water attached to the surface of the bar flows out from gaps among the pipes; then the materials are transported to a second flying shear 10 under the action of a conveying roller way and are sheared into a plurality of sections with equal length;

s6, casting the bar to the cooling bed 11 under the action of the conveying roller way and the steel casting device; the steel throwing device is provided with a walking beam and sequentially throws the bars to the cooling bed 11;

s7, when the bar just enters the cooling bed 11, the temperature in 1m of the head of the bar is consistent with the temperature of other parts, namely 930 +/-30 ℃, and the bar is cooled to 280 +/-30 ℃ by the cooling bed 11 and then enters the cold shearing machine 12 to be sheared into a plurality of sections with the length meeting the requirement; when the bar passes through the water passing pipe, only the temperature of the surface layer is cooled, after the bar leaves the water passing pipe, the surface layer of the bar is heated under the action of the inner core of the bar, the head of the bar passes through the first water passing pipe 6, no cooling water flows in the first water passing pipe 6, and the temperature of the temperature return is high, so that the temperature of the head of the bar is consistent with the temperature of other parts;

and S8, sequentially collecting, bundling, weighing and listing the rods and then warehousing.

The roughing mill group 2, the intermediate mill group 4 and the finishing mill group 5 are used for sequentially increasing the forming precision of rolled bars; the cooling water main is connected with a first water through pipe 6 through a pneumatic three-way valve and connected with a second water through pipe 8 through a flow regulating valve 9; when the first water passing pipe 6 needs to stop supplying water, the pneumatic three-way valve guides out the cooling water originally supplied to the first water passing pipe 6, so that the flow of the second water passing pipe 8 is kept stable; the pneumatic three-way valve and the flow regulating valve 9 are arranged to regulate the temperature of the head of the bar through the water penetrating pipe, so that the temperature of the head of the bar is consistent with the temperature of other parts, the problem that the head of the bar is macroscopically penetrated by water and bright rings is solved, and the macroscopically metallographic phase of the head of a finished bar meets GB/T1499.2-2018 steel for reinforced concrete-the second part: hot rolled ribbed bar "quality requirement.

In light of the foregoing description of the preferred embodiment of the present invention, many modifications and variations will be apparent to those skilled in the art without departing from the spirit and scope of the invention. The technical scope of the present invention is not limited to the content of the specification, and must be determined according to the scope of the claims.