CN-115401155-B - Forging tool and forging method for continuous rolling mill supporting roller

Abstract

The invention relates to a forging tool and a forging method for a continuous rolling mill supporting roller, belongs to the technical field of supporting roller forging, and solves the technical problems of disqualification of flaw detection of a forging center part, more cracks on the forging surface and low forging production efficiency in the prior art. The forging tool comprises a full-coverage wide flat anvil auxiliary tool, wherein the full-coverage wide flat anvil auxiliary tool comprises an upper flat anvil and a lower flat anvil, and the upper flat anvil and the lower flat anvil are identical in structure and size and completely cover blanks arranged between the upper flat anvil and the lower flat anvil. The forging method comprises the steps of 1, carrying out multi-pass square drawing, chamfering and rounding by adopting a full-coverage wide flat anvil auxiliary tool, 2, blanking two ends of a blank after rounding, drawing roll necks of a water gap section and a riser end, and finally finishing a finished product to obtain a continuous rolling mill supporting roll. The invention improves the surface quality of the supporting roller, greatly saves the production cost and improves the production efficiency.

Inventors

• LI JIAO
• CAO MING
• HAN XIAOYU
• PAN LIYONG

Assignees

• 天津重型装备工程研究有限公司
• 中国第一重型机械股份公司

Dates

Publication Date

20260508

Application Date

20210528

Claims (3)

1. 1. A method of forging a tandem mill support roll, the method comprising the steps of: step 1, placing an ingot into a furnace for heat preservation, performing multi-pass square drawing by adopting a full-coverage wide flat anvil auxiliary tool, performing 1-2-pass chamfering after the multi-pass square drawing, and performing multi-pass rounding; The full-coverage wide flat anvil auxiliary tool comprises an upper flat anvil and a lower flat anvil, wherein the upper flat anvil and the lower flat anvil have the same structure and size and completely cover blanks arranged between the upper flat anvil and the lower flat anvil, and zero lap joint of each hammer can be realized during forging; The lengths of the upper flat anvil and the lower flat anvil are 3800-4000mm; the widths of the upper flat anvil and the lower flat anvil are 2300-2500mm; The full-coverage wide flat anvil assistor can realize limit forging, in the limit forging process, the height after pressing is smaller than the final target size, and the minimum size after pressing is calculated according to 0.9 times of the target size; when the full-coverage wide flat anvil auxiliary tool is adopted, the surface of the blank is completely covered by an upper flat anvil and a lower flat anvil, and the surface of the blank between the upper flat anvil and the lower flat anvil is in a compressive stress state; In the step 1, firstly, the blank is put into a furnace for heat preservation before the blank is forged; The heat preservation temperature is 1250+/-10 ℃, and the heat preservation time is more than or equal to 30 hours; In the step 1, after heat preservation, the blank is discharged from a furnace for forging, the initial forging temperature of the discharged forging is 1220+/-10 ℃, and the final forging temperature is 850+/-10 ℃; In the multi-pass square drawing treatment process, the rolling reduction of a single pass square is 30-35% of the height of a blank before rolling, namely, the rolling reduction is determined according to 30-35% of the height of the blank, so that the size after rolling is calculated, the size after rolling is smaller than the target size, and the minimum size after rolling is calculated according to 0.9 times of the target size; the multi-pass square drawing processing process comprises the following steps: The first square drawing treatment is carried out, and the height of the blank after being pressed down is 1300mm plus or minus 10mm; the second pass square drawing treatment, namely turning the blank around the axis of the blank by 90 degrees, wherein the height of the pressed blank is 1530mm plus or minus 10mm; the third square drawing treatment, namely turning the blank around the axis of the blank by 90 degrees, wherein the height of the pressed blank is 1350mm plus or minus 10mm; fourth pass square drawing treatment, namely turning the blank around the axis of the blank by 90 degrees, wherein the height of the pressed blank is 1350mm plus or minus 10mm; fifth pass square drawing treatment, namely turning the blank around the axis of the blank by 90 degrees, wherein the height of the pressed blank is 1400mm plus or minus 10mm; Performing five-pass square drawing compaction, and then performing sixth-pass inverted octagonal treatment and seventh-pass inverted octagonal treatment; A sixth-pass reverse octagonal treatment, namely turning the blank 45 degrees around the axis of the blank, wherein the height of the pressed blank is 1370mm plus or minus 10mm; A seventh-pass reverse octagonal treatment, namely turning the blank around the axis of the blank by 90 degrees, wherein the height of the blank after being pressed down is 1450mm, and then carrying out multi-pass rounding to a supporting roller phi 1510mm; Step 2, blanking two ends of a blank after rounding, wherein the heat preservation temperature is 1250+/-10 ℃, the heat preservation time is more than or equal to 10 hours, the initial forging temperature of discharging forging after heat preservation is 1220+/-10 ℃, and the final forging temperature is more than or equal to 850 ℃; The forging time is shortened to 50min, the equivalent strain value of the forging core can reach 3, and upsetting is avoided and a jaw is not required to be pressed by the forging method.
2. 2. The method for forging a backup roll for a continuous rolling mill according to claim 1, wherein in said step 1, the first firing time, before the billet is forged, the billet is heated for 30 hours.
3. 3. The forging method of a tandem mill supporting roll according to claim 1, wherein in said step 2, the blank after being drawn, chamfered and rounded is subjected to furnace-in heat preservation for 10 hours.

Description

Forging tool and forging method for continuous rolling mill supporting roller Technical Field The invention relates to the technical field of forging of support rolls, in particular to a forging tool and a forging method of a continuous rolling mill support roll. Background Backing rolls are important components of rolling mills to support the work rolls or intermediate rolls to prevent deflection of the work rolls that affects the throughput and quality of the sheet, strip, and thus the quality characteristics of the backing rolls are particularly important. The drawing is a necessary procedure in the forging process of large shaft forgings, is also a main procedure affecting the quality of forgings, reduces the sectional area of the blank by the drawing procedure, increases the length, and plays roles of breaking coarse crystals, forging internal looseness and holes, refining cast structures and the like, thereby obtaining homogeneous and compact high-quality forgings. The traditional continuous rolling mill supporting roller forging method comprises the steps of first-time jaw pressing, chamfering and ingot bottom removing, second-time upsetting, KD drawing or upper flat lower V anvil drawing, and third-time drawing to obtain a finished product. Because the alloy content of the roller material is higher, the main problems in the forging process are that the flaw detection of the core part of the forging is not qualified, the surface of the forging has more cracks, especially in the upsetting process, transverse and smooth lines are extremely easy to damage on the surface of a steel ingot, cracks are easy to appear at the lap joint of a hammer and a hammer in the KD process, the KD rolling reduction is limited, the roll forging production efficiency is severely restricted in the damage clearing process, the rejection risk is faced by heavy people, meanwhile, because the crack damage is heavy, the forging allowance has to be increased, the utilization rate of the forging is generally low, and the product profit rate is reduced. Disclosure of Invention In view of the analysis, the invention aims to provide a forging tool and a forging method for a continuous rolling mill supporting roller, which are used for solving the problems of unqualified flaw detection of the forging center part, more cracks on the surface of the forging and low production efficiency of the forging produced by adopting the conventional continuous rolling mill supporting roller forging method. The aim of the invention is mainly realized by the following technical scheme: In one aspect, the invention provides a forging tool for a continuous rolling mill supporting roll, which comprises a full-coverage wide flat anvil auxiliary tool; the full-coverage wide flat anvil auxiliary tool comprises an upper flat anvil and a lower flat anvil, wherein the upper flat anvil and the lower flat anvil have the same structure and size and completely cover blanks arranged between the upper flat anvil and the lower flat anvil. In one possible design, the upper and lower flat anvils are each 3800-4000mm in length; The widths of the upper flat anvil and the lower flat anvil are 2300-2500mm. On the other hand, the invention also provides a forging method of the continuous rolling mill supporting roll, which adopts the forging tool of the continuous rolling mill supporting roll; the forging method comprises the following steps: Step 1, adopting a full-coverage wide flat anvil auxiliary tool to carry out multi-pass square drawing, carrying out 1-2-pass chamfering after the multi-pass square drawing, and then carrying out multi-pass rounding; And 2, blanking two ends of the blank after rounding, drawing out roller necks of a water gap section and a riser end, and finally finishing a finished product to obtain the continuous rolling mill support roller. Further, in the step 1, firstly, the blank is put into a furnace for heat preservation before the blank is forged; The heat preservation temperature is 1250+/-10 ℃, and the heat preservation time is more than or equal to 30 hours. Further, in the step 1, after heat preservation, the blank is discharged and forged, the initial forging temperature of the discharged and forged is 1220+/-10 ℃, and the final forging temperature is 850+/-10 ℃; the blank discharging forging process comprises the steps of carrying out multi-pass square drawing treatment on the blank by adopting a full-coverage wide flat anvil, forming a square blank after square drawing, and then carrying out chamfering treatment and rounding treatment on the square blank. Further, in the step 2, in the second firing, the blank subjected to square drawing, chamfering and rounding is subjected to furnace charging and heat preservation, the heat preservation temperature is 1250+/-10 ℃, the heat preservation time is more than or equal to 10 hours, and the blank is discharged from the furnace for forging after heat preservation. Further, in the step 2, the