CN116944235A - A rolling method suitable for 16mm three-slit hot-rolled ribbed steel bars - Google Patents

Abstract

The invention belongs to the technical field of rolling treatment, and particularly relates to a rolling method suitable for 16mm three-segment hot rolled ribbed steel bars. According to the scheme, the rolling raw material is heated by a walking beam type heating furnace for 180 t; wherein the rolling raw material is 165×165×12000mm ribbed steel bar; sequentially performing rough rolling, intermediate rolling and finish rolling on the heated rolling raw material; the three-splitting rolling process is adopted by the stepping tooth cooling bed and the phi 16mm specification deformed steel bars, and the rolled products after rolling are subjected to cold shearing and automatic bundling in real time, so that the dimensional accuracy of rolled pieces entering a finishing mill group is ensured.

Description

A rolling method suitable for 16mm three-slit hot-rolled ribbed steel bars

Technical field

The invention belongs to the technical field of rolling processing, and specifically relates to a rolling method suitable for 16mm three-slit hot-rolled ribbed steel bars.

Background technique

At present, in the rolling production process, because the two side line slots of the pre-cut pass wear faster than the center line slot, the inner diameter of the center line of the finished product is smaller than that of the two sides, the height of the longitudinal rib is larger than that of the two sides, and the weight deviation Smaller than the two side lines, in order to ensure that the center line size and weight deviation do not exceed the national standard requirements, the overall size of the finished product is increased by 0.1-0.3mm, which affects the yield rate by about 1%. In other words, during the production process, the 16mm three-cut center line size Exceeding the tolerance will affect product quality.

Therefore, in view of the above-mentioned technical problems and defects, it is urgent to design and develop a rolling method suitable for 16mm three-slit hot-rolled ribbed steel bars.

Contents of the invention

In order to overcome the above-mentioned shortcomings and difficulties in the prior art, the purpose of the present invention is to provide a rolling method suitable for 16mm three-slit hot-rolled ribbed steel bars.

The object of the present invention is to provide a rolling method suitable for 16mm three-slit hot-rolled ribbed steel bars.

The object of the present invention is achieved in this way: the method includes the following steps:

The rolling raw materials are heated in a 180t walking beam heating furnace; wherein the rolling raw materials are 165×165×12000mm ribbed steel bars;

The heat-treated rolling raw materials are sequentially subjected to rough rolling, intermediate rolling and finishing rolling;

Through the stepping gear cooling bed and the three-slit rolling process combined with Φ16mm specification rebar, the rolled products are cold sheared and automatically bundled in real time.

The scheme of the present invention heats the rolling raw materials through a 180t walking beam heating furnace; wherein the rolling raw materials are 165×165×12000mm ribbed steel bars; the heated rolling raw materials are sequentially rough rolled, Intermediate rolling and finishing rolling processing; through the stepping gear cooling bed, combined with the three-cut rolling process of Φ16mm specification rebar, the rolled products are cold sheared and automatically bundled in real time, thereby ensuring guaranteed entry The rolling stock of the finishing mill is of precise dimensions.

In other words, the φ16mm specification rolling mill unit consists of 17 rolling mills, which are divided into rough rolling, intermediate rolling and finishing rolling mills. The steel billet after being discharged from the furnace is transported to the first rolling mill of the rough rolling mill unit by the conveyor roller table. The rolled pieces are rolled without twisting in the rough rolling mill unit (650×3+550×3) with six vertical and horizontal roughing mills arranged alternately. After 1 #The head is cut off by flying shear (the rolled piece can also be broken in case of an accident) and then enters the intermediate rolling mill unit (Φ470×5) with 5 alternating vertical and horizontal rolling mills for twist-free rolling. Micro-tension control is adopted inside the roughing and intermediate rolling mills. The head and tail of the rolled piece are cut off by 2# flying shear, and then enter the finishing rolling mill (Φ380×6) for rolling. It is equipped with a pneumatic vertical looper to enable tension-free rolling of the rolled pieces in this area, thereby ensuring accurate dimensions of the rolled pieces entering the finishing rolling unit.

Description of the drawings

Figure 1 is a schematic flow chart of a rolling method suitable for 16mm three-slit hot-rolled ribbed steel bars according to the present invention;

Figure 2 is a schematic flow diagram of an embodiment of a rolling method suitable for 16mm three-slit hot-rolled ribbed steel bars according to the present invention;

Figure 3 is a schematic diagram of the original design of the 16H imported rolling guide roller according to the embodiment of the present invention, which is a rolling method suitable for 16mm three-slit hot-rolled ribbed steel bars;

Figure 4 is a schematic diagram of the current design of a 16H imported rolling guide roller suitable for a rolling method of 16mm three-slit hot-rolled ribbed steel bars according to the present invention;

In the picture:

1-The angle between the original guide rollers; 2-The angle between the new guide rollers.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings, but the present invention is not limited in any way. Any transformation or replacement based on the teachings of the present invention falls within the protection scope of the present invention.

As shown in Figures 1-4, the present invention provides a rolling method suitable for 16mm three-slit hot-rolled ribbed steel bars.

The method includes the following steps:

S1. Heat the rolling raw materials through a 180t walking beam heating furnace; wherein the rolling raw materials are 165×165×12000mm ribbed steel bars;

S2. Carry out rough rolling, intermediate rolling and finish rolling on the heated rolling raw materials in sequence;

S3. Through the stepping gear cooling bed and the three-cut rolling process combined with Φ16mm specification rebar, the rolled products are cold sheared and automatically bundled in real time.

The heating treatment in the walking beam heating furnace is specifically heating to 1000-1060°C for rolling.

The step of sequentially carrying out rough rolling, intermediate rolling and finishing rolling on the heat-treated rolling raw materials also includes the following steps:

S21. Combined with the six rolling mills set up, perform the first micro-tension rolling on the heated rolling raw materials, and perform the first flying shearing treatment on the rolled products;

S22. Combined with the six rolling mills set up, the rolling raw materials processed by the first flying shear are subjected to the second micro-tension rolling, and the rolled products are subjected to the second flying shearing process;

S23. Combined with the set-up of 6 rolling mills and vertical loopers, tension-free loop rolling is performed on the rolling raw materials processed by the second flying shear, and the third flying shear processing is performed on the rolled products.

The combined set of 6 rolling mills performs the second micro-tension rolling on the rolling raw materials processed by the first flying shear, and performs the second flying shear processing on the rolled products, and also includes:

S221. After the second micro-tension rolling, perform pre-controlled cold treatment on the rolled products in real time.

The rolling speed of the tension-free loop rolling is 13.5m/s. The included angle of the guide rollers in the tension-free loop rolling is 120 degrees.

The above-mentioned step-tooth cooling bed is combined with the three-slit rolling process of Φ16mm specification rebar to cold-cut and automatically bundle the rolled products in real time, which also includes:

S231. Use at least one 850t cold shear to cold-shear the rolled products, and use at least one automatic baling machine to automatically bundle the cold-sheared rolled products.

The first micro-tension rolling is rough rolling of the raw material to be rolled. The second micro-tension rolling is an intermediate rolling of the raw material to be rolled. The first micro-tension rolling is finish rolling of the raw material to be rolled.

Specifically, in a specific embodiment of the solution of the present invention, the rolling raw material of the solution of the present invention is 165×165×12000mm, and is heated to 1000-1060°C through a 180t walking beam heating furnace for rolling. There are a total of 18 rolling mills, which are arranged alternately between horizontal and vertical rolling mills (No. 14 is a flat-vertical convertible rolling mill), and are divided into three rolling mills: rough rolling, intermediate rolling and finishing rolling. Each unit consists of 6 rolling mills. The finishing rolling mill unit is equipped with 6 vertical loopers. The rolled pieces are rolled with micro-tension in the roughing and intermediate rolling mill units and tension-free loop rolling in the finishing rolling mill unit to improve the dimensional accuracy of the product. Φ16mm specification rebar adopts three-slit rolling process, and the rolling mill pass system adopts elliptical-round pass system. The full-line rolling mill is a high-rigidity short-stress line rolling mill, and the maximum rolling speed of the finishing rolling mill is 13.5m/s. The rolling line is also equipped with 3 flying shears, and the finishing area has a stepping gear cooling bed, an 850t cold shear and an automatic baling machine.

Preferably, the original pass type system of the finishing mill uses holeless-box-pre-slit-slit-K2-K1. The redesigned pass system 13H14V17H18H pass pattern remains unchanged, and only the 15H16H pass pattern changes.

The inlet and outlet guide assemblies of the finishing mill continue to use the original pass guides. The 16H imported guide roller is redesigned according to the new hole pattern, and the included angle of the original 16H imported guide roller is set from the original 110° angle 1 to 120° angle 2.

The hole pattern and guide of the present invention: use a hole pattern system to redesign the 15H and 16H hole patterns, and reduce the hole pattern on the basis of the original hole pattern. The width of the 15H hole pattern is reduced from the original hole pattern 68.7mm to 65.05 mm, the 15H sideline height increased from the original 20.5mm to 21.6mm; the 16H hole width decreased from 68mm to 66.73mm, the hole height decreased from 19.6mm to 19.4mm, and the hole radius decreased from the original center line 9.6mm to the sideline 9.8mm. To the third line of 9.5mm, the roll gap value is reduced from 1.0mm to 0.8mm.

The 16H imported guide roller is redesigned based on the 15H pass shape, and the included angle of the guide roller is optimized from the original 110° to 120° to make it consistent with the size and shape of the rolled piece to ensure good holding effect.

Rolling method of the present invention

(1) Rough rolling process parameter table: The rough rolling mill has 6 passes, and the pass shape distribution is no hole-no hole-elliptical-circle-elliptical-circle. There is no change in the material shape size before and after the improvement.

Table 1 Rough rolling pass rolling parameter table

(2) Intermediate rolling process parameter table

The intermediate rolling mill rolls for 5 passes, and the pass distribution is oval-circle-oval-circle-no hole. After improvement, the pass shape remains unchanged, and the size of the 7H-11H material is adjusted (see Table 2 and Table 3 for details).

Table 2 Rolling parameters of original pass type in rolling

Table 3 Pass rolling parameters after improved medium rolling

(3) Comparison of the finishing rolling process parameter tables before and after the improvement, and the changes in the roll gap value of the 13H-16H material type. See Table 4 and Table 5 for details.

Table 4. Rolling parameter table of original pass type for finishing rolling

Table 5 Rolling parameter table after improvement of finish rolling

This invention mainly optimizes the design of the 15H16H pass system and guide size of the finishing mill, and optimizes the design of the 13H14V material size. Under the condition of maintaining the original process of 17H18H, the φ16 specification three-line finished product size deviation is small, and the center line of the original pass system is solved. The problem of small size and difficulty in adjustment has good production and application effects and promotion and application value.

The specific implementation steps of the design of the present invention are as follows:

1. The layout of the rolling mill and pass pattern remains unchanged. The newly designed 15H16H pass pattern replaces the original 15H16H pass pattern, and the material size 13H~16H is optimized (see Table 1 and Table 2 for details).

2. Design the size of the 16H imported guide roller, and the guide body will follow the original design.

3. During the rolling process, the opening of the inlet guide of the 14V-17H rolling mill is fine-tuned according to the size of the rolled piece to achieve the most appropriate and stable rolling operation.

Example 1

1. The chemical composition of Φ16mmHRB500E is C content 0.21%-0.25%, Si content 0.45%-0.51%, Mn content 1.46%-1.55%, S content 0.017%-0.029%, and P content 0.015%-0.031%. The chemical composition of Φ16mmHRB400E is C content 0.21%-0.25%, Si content 0.45%-0.50%, Mn content 1.36%-1.46%, S content 0.009%-0.020%, and P content 0.017%-0.022%.

Table 6 Chemical composition of 16mm specification rolling

2. The inner diameter deviation of the improved finished product size is 0.10mm, and the transverse rib height, longitudinal rib height, rib spacing, and transverse rib end clearance all meet the national standard requirements (see Table 7 and Table 8 for details); 3 test pieces were taken from each furnace number. The weight deviation value of the sample is detected. The difference in weight deviation value between the cutting center line and the side line is within 0.4%. The weight deviation can be controlled within a range of -3.7%--4.5%. The fluctuation range is reduced, which reduces the quality risk of weight deviation.

Table 8 Weight deviation detection results

Rolling batch number Edge weight deviation 1 (%) Centerline weight deviation (%) Edge weight deviation 2 (%) L1****195 -4.2 -4.3 -4.1 L1****196 -4.5 -4.6 -4.5 L1****197 -4.2 -4.2 -4.3 L1****198 -4.1 -4.3 -4.0 L1****199 -4.4 -4.2 -4.3 L1****200 -4.3 -4.0 -4.1 L1****201 -4.3 -4.2 -4.2 L1****202 -4.0 -4.2 -4.3 L1****203 -4.0 -4.3 -4.2 L1****204 -3.9 -4.1 -4.0 L1****206 -3.9 -4.2 -3.9 L1****207 -3.8 -4.0 -3.7 L1****208 -4.2 -4.1 -4.2 L1****209 -4.4 --4.2 -4.3 L1****210 -4.3 -4.2 4.1 L1****211 -4.2 -4.5 -4.4 L1****212 -4.0 -4.2 -4.2 L1****213 -3.8 -4.0 -4.0 L1****214 -3.9 -3.8 -3.7 L1****215 -3.8 -3.9 -3.8 L1****216 -4.0 -4.1 -4.0

3. Improved mechanical properties: φ16mmHRB500E yield strength 520-550MPa, tensile strength 675-710MPa, elongation 18%-24%, strength-to-yield ratio 1.28-1.30, total elongation 11.4%-16.4%, yield Ratio 1.04-1.10. φ16mmHRB400E has a yield strength of 415-440MPa, a tensile strength of 585-605MPa, an elongation of 20%-26%, a strength-to-yield ratio of 1.38-1.43, a total elongation of 13.0%-16.1%, and a yielding ratio of 1.04-1.10. The mechanical properties meet the national standard requirements.

Table 9 Mechanical properties of φ16mm specification

Rolling batch number Trademark Specification Lower yield strength REL tensile strength Elongation strong kyu ratio Maximum force total elongation Ququbi L12340195 HRB500E 16 530 685 19 1.29 11.6 1.06 L12340196 HRB500E 16 540 700 18 1.3 11.7 1.08 L12340197 HRB500E 16 535 685 twenty four 1.28 16.4 1.07 L12340198 HRB500E 16 535 685 twenty three 1.28 14.6 1.07 L12340199 HRB500E 16 545 700 19 1.28 13 1.09 L12340200 HRB500E 16 520 675 twenty one 1.3 11.9 1.04 L12340201 HRB500E 16 535 695 18 1.3 11.4 1.07 L12340202 HRB500E 16 525 685 20 1.3 12.2 1.05 L12340203 HRB500E 16 530 685 20 1.29 12.6 1.06 L12340204 HRB500E 16 530 685 twenty three 1.29 12 1.06 L12340205 HRB500E 16 530 690 twenty two 1.3 12.3 1.06 L12340206 HRB500E 16 545 705 19 1.29 11.4 1.09 L12340207 HRB500E 16 520 675 twenty three 1.3 12.4 1.04 L12340208 HRB500E 16 540 695 18 1.29 12 1.08 L12340209 HRB500E 16 545 705 20 1.29 11.7 1.09 L12340210 HRB500E 16 550 710 19 1.29 11.7 1.1 L12340211 HRB500E 16 535 690 20 1.29 11.9 1.07 L12340212 HRB400E 16 420 585 25 1.39 15.2 1.05 L12340213 HRB400E 16 420 600 20 1.43 13 1.05 L12340214 HRB400E 16 440 605 26 1.38 16.1 1.1 L12340215 HRB400E 16 415 595 twenty two 1.43 13.7 1.04 L12340216 HRB400E 16 430 610 twenty two 1.42 13.5 1.08

Claims (10)

1. A rolling method suitable for 16mm three-slit hot-rolled ribbed steel bars, characterized in that the method includes the following steps: The rolling raw materials are heated in a 180t walking beam heating furnace; wherein the rolling raw materials are 165×165×12000mm ribbed steel bars; The heat-treated rolling raw materials are sequentially subjected to rough rolling, intermediate rolling and finishing rolling; Through the stepping gear cooling bed and the three-slit rolling process combined with Φ16mm specification rebar, the rolled products are cold sheared and automatically bundled in real time. 2. A rolling method suitable for 16mm three-slit hot-rolled ribbed steel bars according to claim 1, characterized in that the heating treatment in the walking beam heating furnace is specifically performed by heating to 1000-1060°C. rolling. 3. A rolling method suitable for 16mm three-slit hot-rolled ribbed steel bars according to claim 1, characterized in that the heat-treated rolling raw materials are sequentially subjected to rough rolling, intermediate rolling and finishing. Rolling treatment also includes the following steps: Combined with the set-up of 6 rolling mills, the first micro-tension rolling is performed on the heated rolling raw materials, and the first flying shearing treatment is performed on the rolled products; Combined with the set-up of 6 rolling mills, the rolling raw materials processed by the first flying shear are subjected to the second micro-tension rolling, and the rolled products are subjected to the second flying shearing process; Combined with the set-up of 6 rolling mills and vertical loopers, the rolled raw materials processed by the second flying shear are rolled with tension-free loops, and the rolled products are processed by the third flying shear. 4. A rolling method suitable for 16mm three-slit hot-rolled ribbed steel bars according to claim 3, characterized in that the six rolling mills arranged in combination are used for the first flying shearing treatment. The raw materials are subjected to a second micro-tension rolling, and the rolled products are subjected to a second flying shear process, which also includes: After the second micro-tension rolling, the rolled products are pre-controlled and cooled in real time. 5. A rolling method suitable for 16mm three-slit hot-rolled ribbed steel bars according to claim 3, characterized in that the rolling speed of the tension-free loop rolling is 13.5m/s. 6. A rolling method suitable for 16mm three-slit hot-rolled ribbed steel bars according to claim 3 or 5, characterized in that the included angle of the guide rollers in the tension-free loop rolling is 120 degrees. 7. A rolling method suitable for 16mm three-cut hot-rolled ribbed steel bars according to claim 1, characterized in that the step-toothed cooling bed is used in combination with Φ16mm specification rebar using three-cut The rolling process is divided into cold shearing and automatic bundling of rolled products in real time, including: Use at least one 850t cold shear to cold-shear the rolled products, and use at least one automatic baling machine to automatically bundle the cold-sheared rolled products. 8. A rolling method suitable for 16mm three-slit hot-rolled ribbed steel bars according to claim 3, characterized in that the first micro-tension rolling is rough rolling of the raw material to be rolled. 9. A rolling method suitable for 16mm three-slit hot-rolled ribbed steel bars according to claim 3, characterized in that the second micro-tension rolling is an intermediate rolling of the raw material to be rolled. 10. A rolling method suitable for 16mm three-slit hot-rolled ribbed steel bars according to claim 3, characterized in that the first micro-tension rolling is finish rolling of the raw material to be rolled.