JPS6257409B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a new method for manufacturing a composite roll in which the main part of the roll is overlaid with a different material.

For example, in a rolling caliber roll, in order to improve the properties of the caliber part, which is the main layer used, this part is sometimes coated with a different material with high wear resistance, such as stellite, and used as a composite roll. be. In this case, the method of overlaying the dissimilar material is mainly to first form a built-up layer by welding overlay method, and then finish the surface into a predetermined shape by machining. However, according to such conventional methods, even if the foreign material itself has excellent wear resistance and crack resistance, the integrity of the weld between the build-up part and the roll,
The overlay structure cannot be sufficiently homogeneous, and there is a risk of localized wear and cracks due to the unique properties of welding.As a result, even if a part of the roll has high performance, the roll as a whole has unstable characteristics. There were problems to be had.

In view of the above problems, the present invention aims to stably improve the performance of this type of composite roll by using the known rotary forging method as a roll manufacturing method, and also improve the production efficiency. Therefore, the present invention provides a method for manufacturing this type of composite roll, in which a desired material is overlaid on a required part of the roll, and then the roll is heated in the vicinity of the overlay part. It is characterized in that a pressure forming roller is pressed under the rotational drive of the overlay, and the built-up portion is pressed into a predetermined shape and is pressed onto the roll.

The present invention will be described below with reference to FIGS. 1 to 4, taking as an example the case of manufacturing a composite caliber roll.
First, the roll to be combined is processed in advance into a shape similar to a predetermined caliber part shape by machining or the like. At this time, this part is of course larger than the predetermined size (for example, 10
~15mm) is processed. As shown in FIG. 2, the roll having the recessed portions is coated with a flux 3 for preventing oxidation on the recessed portions 2 of the roll 1 and the surface near the recessed portions. After that, the roll 1 is heated to an appropriate build-up preheating temperature (for example, 550 to 700
C), and while the roll 1 is rotated in this state, the concave portion 2 is overlaid with a different material 4 according to the purpose, as shown in FIG. Regarding the types of different materials used, Stellite (Co-Cr-W alloy),
Examples include Cr steel and Ni-Cr steel, and methods such as inert gas arc welding and submerged arc welding are used as overlay methods. The above process of overlaying different materials is performed in substantially the same manner as in the conventional manufacturing method. In addition, in this method, it is also possible to carry out overlaying of different materials by setting the roll 1 in a rotary forging device to be described later and rotating the device.

However, in the conventional method, as shown in Figure 3, the build-up part 4
After forming the roll, it is machined to complete a composite roll of a predetermined shape, and this method is characterized in that it is rotary forged. That is, the roll 1 with the built-up part 4 provided in the recessed part 2 is reheated to a temperature that promotes plastic deformation of at least the surface layer near the built-up part 4 (for example, the temperature up to about 20 mm from the surface is heated to (heat up to 1150℃). Next, in this heated state, the roll 1 is rotated around its axis as shown in FIG. 1 (the built-up part 4 is omitted for convenience) and FIG. is pressed against the press-forming roller 5 having a peripheral edge shape that matches the predetermined caliber shape, and the built-up portion 4 and a part of the roll 1 that receives its ripple effect undergoes plastic deformation, and when the roller 5 enters the As a result, the built-up portion 4 is forged into a predetermined caliber shape. After the built-up portion 4 is forged into a predetermined caliber shape, unnecessary extra-thickness portions 6 may be raised on both sides, but these can be easily removed by finishing.

Regarding the rotary forging equipment used to implement this method,
The apparatus for manufacturing caliber rolls as shown in FIG. 1 can be used as is. That is, in the figure, 7, 7 is a support body that supports the roll 1 so as to be rotatably driven from both ends in conjunction with a rotary drive body (not shown), and 8 is a roller shaft provided close to and parallel to the roll 1; A pressure forming roller 5 is installed in the middle, and usually two or three roller shafts 8 and therefore rollers 5 are provided around the roll 1 at equal intervals.

In the composite caliber roll manufactured using the rotary forging method as described above, the build-up part 4 and a part of the roll 1 undergo plastic deformation due to the pressure of the roller 5, and the build-up part 4 and roll 1 In addition to being crimped together, the structure of the built-up part 4 and the structure of the joint with the roll 1 are homogenized, and as a result, the caliber recess covered with different materials is free from the risk of local wear and cracks. It has been improved to have more stable performance than before, and its durability has been improved. Further, after the built-up part 4 is forged by the roller 5, the final finishing process can be easily performed, and it is more efficient than the case where the shape is formed by conventional machining.

Specific examples of manufacturing composite caliber rolls by the method of the present invention are as follows.

Example Body size made of carbon steel S45C material: 350〓×300
A semicircular recess with a radius of 30 mm was formed as a caliber mold on a roll of 30 mm in diameter. This was charged into a rotary heating furnace and the entire body was heated to 600℃, and immediately after taking it out of the furnace, it was poured into the recess of Stellite No. 1 (31% Cr, 13
%W, 2.5%C, balance Co) was overlaid to 14mm. This was then charged into the heating furnace again, heated to 1100°C and held for 20 minutes, then set in a rotary forging device as shown in Figure 1, and pressed with a pressure forming roller having an arcuate peripheral edge with a radius of curvature of 18 mm. Pressure was applied rotationally to the recess.
At the initial stage of forging the built-up part, the roller load was set to about 5 tons, and gradually increased to a final pressure of about 50 tons to forge the recessed part. Next, this composite roll is annealed, then spray quenched at 1130°C, and then heated to 580°C.
Tempering was carried out at ℃. As a result of disassembling the composite roll made in this way and measuring its hardness, it was found that H _RC was uniformly 55 to 56 from the surface of the concave part to the joint part.
It was confirmed that the material structure of the built-up part was homogeneous.

Although the above description has been made using a composite caliber roll as an example, the present invention is similarly applicable to other types of composite rolls as shown in FIGS. 5 and 6.
FIG. 5 shows an example of a composite roll for flat plates. In this case, the roll 1' has a small diameter part 2' formed in the part intended for composite, and a different material 4' is overlaid on this part. By rotary forging the raised portion 4' using a pressure forming roller 5' having a flat peripheral edge shape, a desired composite roll having a predetermined shape is similarly produced. FIG. 6 shows an example of a composite roll for angle convex rolls. In this case, roll 1" has a small diameter part similar to the predetermined roll shape, with the part intended for composite (the convex part and the areas near both sides thereof). 2", a different material is overlaid 4" on top of this, and this overlay 4" is formed using a pressure forming roller 5" having a peripheral edge shape corresponding to the predetermined convex shape. By rotary forging, purpose composite rolls of a predetermined shape are likewise produced.

As explained in detail above, the present invention is an epoch-making method that utilizes the rotary forging method as a manufacturing method for various composite rolls in which the main parts of the roll are coated with different materials. According to the manufacturing method, healthy crimp integration between the build-up part of the dissimilar material and the roll is achieved, and the structure of the build-up part and its vicinity is made homogeneous,
This completely eliminates the risk of localized wear and cracks, thereby increasing the usability of this type of composite roll and making it stable and durable for long-term use. In addition, this method uses a rotary forging method to press-form the built-up part into almost a predetermined shape, and compared to conventional machining, the processing required to finish is simpler and production efficiency is improved. It will be done.

[Brief explanation of the drawing]

Figures 1 to 4 show an example of manufacturing a composite caliber roll according to the present invention, Figure 1 is a plan view of the main parts showing the roll and rotary forging equipment, and Figure 2 shows the process of coating with anti-oxidation flux. Cross section, 3rd
FIG. 4 is a sectional view showing the overlay part heading process, and FIG. 5 is a sectional view showing the heading process showing an example of manufacturing a roll for a composite flat plate according to the present invention. , FIG. 6 is a cross-sectional view of the forging process showing an example of manufacturing a composite convex roll. 1, 1', 1''...Roll, 2, 2', 2''...Concave portion (or small diameter portion), 3...Flux for preventing oxidation, 4, 4', 4''...Different material overlay, 5 ,5',
5″...Roller for pressure forming, 6...Excess portion, 7
...Support, 8...Roller shaft.

Claims (1)

[Claims] 1. In manufacturing a composite roll in which a desired part of a roll is overlaid with a different material, the desired different material is overlaid on the required part of the roll, and then the roll is heated in the vicinity of the overlay part. 1. A method for producing a composite rotary forging roll, which comprises pressing a pressure forming roller under the rotational drive of the roller to press the overlay part into a predetermined shape and press it onto the roll.