JPS6199556A - Method and production of composite roll - Google Patents

Abstract

PURPOSE:To join thoroughly the outside layer material and inside layer material of a composite roll and to prevent the variance of quality by forming preliminarily the outside layer material into a hollow shape and pouring a molten metal into the hollow part to form the core material. CONSTITUTION:The outside layer material 4 of the roll having a prescribed size is installed to the projecting part of a dummy bar and an integral cylindrical metallic mold 3 provided with a high-frequency induction heating coil 8 is installed around said material. A sealing cover 6 is attached thereto and gaseous Ar is blown from a gaseous Ar blow-off nozzle 7 and is blown off through a blow-off nozzle 9. The preheating by the coil 8 is stopped when the material 4 attains the prescribed temp. A long nozzle is inserted from the upper part of the cover 6. The molten metal is poured to the inside surface side of the material 4 in a non-oxidizing atmosphere and is pressurized by a plunger 11. The molten metal is pressurized by plungers 11, 13 after a jig 2 for holding the dummy bar is opened to lower the dummy bar 1 and the composite roll along guide rolls 14. The heated composite roll is cooled with cooling water nozzles 15.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of the Invention] The present invention relates to a method and apparatus for manufacturing composite rolls, particularly composite solid rolls, used as rolling roll materials, binion gear materials, and the like.

[Conventional method for manufacturing composite rolls]

Conventionally, a method of manufacturing a composite roll by casting a molten metal around a preformed solid or hollow pipe has been proposed.

(Japanese Patent Publication No. 44-4905 and Japanese Patent Application Laid-Open No. 48-539
See Publication No. 36. ) To explain this conventional method in more detail, the stone material (inner layer material) of the composite roll is formed in advance, and molten metal is cast around the stone material (inner layer material) to form the outer layer material of the composite roll. It is something that makes you

[Object of the present invention]

The present invention provides a novel method and apparatus for manufacturing a composite roll, which is different from the above-mentioned conventional means.Specifically, the outer layer material of the composite roll is formed into a hollow shape in advance, which is the opposite of the conventional means. Then, molten metal is injected into this hollow part to form stone (inner layer material of the composite roll) 5i-1.The purpose is to provide a novel method and artificial device for manufacturing a composite roll that is completely unprecedented today. shall be.

[Sakaki Sei of the present invention]

As described above, in the present invention, the outer layer material of the joining roll is prepared in advance into a hollow KE? ? The stone material (inner layer material of the composite roll) is formed by shaping the material into a shape and injecting molten metal into the hollow part. Furthermore, the present invention adopts a molten metal pressurization method and joins the outer layer material and core material of the composite roll in a non-oxidizing atmosphere. That is, the present invention provides (1) in manufacturing a composite roll that is molded on the inner surface of a cylindrical-interrupted type, a soot layer corresponding to the outer layer of the composite roll is manufactured.
The part to be molded is pre-formed into a hollow roll shape, the hollow roll is placed on the inner surface side of the mold, and then preheated in a non-oxidizing atmosphere,
Next, a method for manufacturing a composite roll, which comprises pouring molten metal such as cast steel into the hollow part of the hollow roll, pressurizing the poured part with a press, and then cooling it.

(2) A cylindrical-stop mold for molding and pressurizing the composite roll and its preheating device, a dummy bar for holding the molten metal, a press for pressurizing the molten metal that will become the stone material of the composite roll, and preheating of the mold. A composite roll comprising an oxidation-free device for maintaining the non-oxidation state of the joint surface to be cast-wrapped, a sensor for detecting molten metal, and a cooling zone for cooling the casting after solidification under pressure. Manufacturing equipment.

I'll go.

The present inventor conducted a preliminary test using a carbon steel pipe as the outer layer material of a composite roll and cast iron and molten steel as the stone material (inner layer material). That is, a surface treatment agent tm is applied to the hollow inner surface of a hollow carbon steel pipe, and after preheating to 1200°C, cast iron and molten steel are poured into this hollow part, and after cooling, the cross section of the vaginal composite roll is
investigated. As a result, it was confirmed that there was a metallurgical bond between the carbon steel pipe and cast iron. The purpose of using a surface treatment agent is to prevent oxidation of the joint surface, but this agent has the disadvantage of causing gas defects or inclusions, as will be described later.

In addition, the present inventor conducted a preliminary test using a cast steel pipe as the outer layer material of the composite roll and molten cast steel of the same material as the inner layer material. In other words, a hollow cast steel pipe is made of 12
When the molten steel of the rear material preheated to 00°C was poured and the joint state was investigated, no joint was found. When looking at the situation in this case in the cross-sectional direction, the inner layer, which is the core material of the composite roll, shrunk uniformly with respect to the hollow inner surface of the cast steel pipe covered with the outer layer material, leaving a gap of about 1 inch.

The biggest reason for this is the difference in thermal expansion coefficients of the combined materials. Another important point to consider is that as a cast-in condition, bonding will not occur unless the molten metal is held at a temperature with a liquid phase ratio of 30% or more for 10 seconds or more. Therefore, in the case of the present invention, attention is paid to the adoption of the molten metal pressurization method in order to make the difference in coefficient of thermal expansion and casting conditions advantageous.

That is, the present invention employs a molten metal pressurization method for the inner layer in order to completely bond the outer layer (a pre-formed hollow roll made of solid material) forming the composite roll.

Then, it is necessary to heat the outer layer of the composite roll, but during this preheating, the joint surface (hollow inner surface) is brought into a non-oxidizing atmosphere, and then molten metal is poured into the joint. In addition, in the conventional pouring process, a surface treatment agent is used to prevent oxidation of the joint surface, but this treatment agent does not cause gas defects or inclusions, and complete joints cannot be achieved continuously. In the present invention, such processing agents are not used at all.

[Example (manufacturing example of composite roll)]

An example of manufacturing a composite roll, which is the first invention of the present invention, will be explained in detail below, divided into roll specifications, manufacturing conditions, and manufacturing steps.

Roll specifications The specifications of the composite roll to be manufactured are as follows.

(1) Outer layer material: 250r cast iron (wear-resistant material) (
2) Outer layer dimensions Outer diameter 300φ x Inner diameter 240φ x Length 1000 (gourd) (3) Inner layer material 8046 (4) Inner layer dimensions Inner diameter 240φ x Length 1800 (
fi) Manufacturing conditions The manufacturing conditions are as follows.

(1) Outer layer material preheating temperature 400℃ (However, when preheating V
C was sealed to prevent oxidation of the joint surface. ) (2) Inner layer material casting temperature 1550℃ (3) Molten metal pressing force (-1 plunger) 226 tons (stress 5 1 kg/■2) (4
) Molten metal pressurizing time 60 seconds (5) Outer layer pressurizing force (Arashi 2 plunger) 52 tons (stress 2 kg/m'') Note) A maximum pressurizing force of 500 tons was used with a vertical press.

Manufacturing Process The process of manufacturing a composite roll according to the above specifications and manufacturing conditions will be explained based on FIGS. 1 to 3. FIG. 1 is a diagram showing the molten metal being pressurized in the composite roll manufacturing apparatus which is the second invention of the present invention, FIG. 2 is a detailed view of the seal cover, and FIG. 5 is a diagram showing the molten metal being poured. In addition, the details of FIGS. 1 to 3 will be explained in the example (example of composite roll manufacturing apparatus) described later.
Here, only the essential parts of the manufacturing trap for composite rolls will be cited and described.

(1) Outer diameter 300φ x inner diameter 240φ x length 1000mm
4 tons of outer layer material manufactured by casting method and provided separately. However, after machining (smooth finish) the joint surface on the inner surface of the outer layer material 4,
The surface is thoroughly degreased with trichlorethylene.

(2) Hold the dummy par 1 on the dummy par jig 2,
An outer layer material 4 is installed on the convex portion of the dummy par 1.

(3) After that, around the outer layer material 4, inner diameter 305φ x outer diameter 4
A cylinder-stop type 3 with a length of 00X and a length of 2300 is installed. However, there is a removable vertical drive machine S on the outer periphery of the mold 3.
(Range 200x/min ~ 1000x/min)t
- A high frequency induction heating coil 8 is attached.

(4) The high-frequency heating coil 8t is driven up and down to preheat the mold 3 and the outer layer material 4t. In this case, the inner surface of the outer layer material 4 is preheated uniformly (top, bottom, center) to 1:400°C. do. However, at the start of preheating, in order to prevent oxidation of the inner surface of the outer layer material 4, Ar gas is continuously blown from the Ar gas blowing nozzle 7 and the seal cover 6t attached to the blowing nozzle 9i. It was crowded.

(5) When the inner surface of the outer layer material Δ reaches 400°C, stop preheating. However, the gas is continuously blown in, and after removing the upper lid 18 of the seal cover 6, the tundish 19 with a long nozzle is inserted into the upper hole of the seal cover 6.

(6) After pouring the pre-melted molten metal (8046) into the ladle 17, pour the 1550°C molten metal onto the inner surface of the outer layer material 4 through the tandy 7 unit 195c. However, the amount of poured molten metal is detected by a sensor 20 attached to the inner surface of the outer layer material 4.

(7) After pouring the molten metal, remove the tundish 19 and the 6ft seal cover, and immediately pressurize the molten metal gradually with the plunger 11 of the 1,500-ton rigid press to a pressure of 22
Although the load was up to 6 tons, the pressurization time during this time was about 60 seconds.

(8) After the above operation is completed, open the dummy par holding jig 2 and at the same time inject high pressure water from the cooling nozzle 15 of the cooling zone attached to the lower part of the device.

(9) Immediately, the heated composite roll is pressurized by the -1 plunger 11 and the 2nd plunger 13, and the dummy par 1 and the composite roll are lowered by applying oil to the guide roll 14, and at the same time are cooled in the cooling zone. Then, a composite roll material T-manufactured. Are the joints of composite rolls completely joined? confirmed.

[Example (Example of composite roll manufacturing device)]

An embodiment of the composite roll manufacturing apparatus, which is the second invention of the present invention, will be described in detail along with its operation based on FIGS. 1 to 3. 1t - Install dummy par holding jig 2
It is held at

A roll outer layer material 4 of predetermined dimensions (length, wall thickness) is installed on the convex portion of the dummy bar 1. A cylindrical-rod mold 3 attached to a high-frequency IU conductive heating coil 81 is installed around it. In addition, if the roll outer layer material 4 is required only near the center of the roll, insert the size adjusting material 5 at both ends of the roll.However, if the roll outer layer material 4 is to be mass-produced with a fixed size, the roll outer layer material 4 It is desirable to use a cylindrical-rod mold 5 in accordance with the method 4.A seal cover 6 is attached to the inner surface of the roll outer layer material 4 to prevent oxidation and also serves as a pouring port, and argon gas is blown from an Ar gas blowing nozzle 7. 6"・91f
l/j: A, 9 times 89 001'
Blowing is continued until the inner surface 01lI (joint surface) of the roll outer layer material 4 reaches a predetermined temperature and the pouring is completed. However, when the roll outer layer material 4 reaches a predetermined temperature, preheating by the high frequency rust induction heating coil 8 is stopped. Then, after removing the top lid 18 of the cool cover 6, a long nozzle attachment is inserted and installed from the top of the seal cover 6.

The molten metal inserted into the ladle 17 is poured into the inner surface of the outer layer material 4 in a non-oxidizing atmosphere through the tundish 19. however,
The amount of poured molten metal is determined by a sensor 20 attached to the inner surface of the dimension adjustment material 5.
Detected at.

Immediately after pouring the molten metal, the seal cover 6 and the tundish 19 are removed, and then the molten metal is pressurized by the plunger 11 of the vertical press. However, there is a + on the top of the dimension adjustment material 5! 12t of air holes are provided when the plunger 11 is inserted. Immediately after releasing the dummy bar holding jig 2, the rod 1.2 plunger 1
1.13, the dummy par 1 and composite roll guide roll 14 are overflowed and lowered, and the heated composite roll is cooled with a water cooling nozzle 15. In addition, in FIG. 1, the dummy par 1 and the mold set are installed on the pedestal 16 and preheated at the same time. I can't help it.

The manufacturing method and manufacturing apparatus of the present invention have been described above with reference to examples, but to explain the present invention in more detail, the manufacturing process of the present invention is a theoretical formulation of basic cast-in conditions. In other words, the casting condition is such that the joining interface temperature of the material to be cast-in (outer layer material 4 in the present invention) is molten metal (8046 in the present invention).
) is exposed to a liquid phase ratio of 30% or more, and at this temperature [1
This condition is satisfied if it is held for 0 seconds or more. In the case of the present invention, in order to satisfy the above conditions, the outer layer is preheated, and in addition, taking into consideration the shrinkage rate of the molten metal, a pressurizing operation is performed in the liquid state (molten metal) for about 60 seconds.

During this pressure edging, the cast-in material (outer layer material 4) and the cast-in material (
A welding phenomenon (
At the same time, a diffusion phenomenon occurs), and directional solidification is imparted to the inner layer material 10, which becomes stone in the subsequent roll cooling process, so that a desired composite roll can be manufactured.

If the outer layer material 4 is a metal material, it will be water-cooled after pouring and pressurizing, but if it is made of ceramic or the like, it will have problems with toughness and thermal shock resistance, so it will be air-cooled.

In the present invention, when manufacturing a composite roll, the combination of materials for the outer layer is arbitrary, but the following combinations of materials are preferred.

(1) Outer layer material (those with wear resistance, thermal shock resistance, and thermal fatigue resistance) - Cast iron type 150r type, ZS Or type acicular cast iron, etc. that are used as annular roll materials e steel type NiNi-0r- Steel, Or-Mo '71
4. Those used as annular roll materials, such as 130r steel.

However, it is considered a promising roll material in the future. Sintered alloys are also good.

(2) Inner layer material (those with toughness) Steel type Carbon cast steel, low alloy cast steel (NiNi-0r-steel, etc.) In the present invention, the conditions for casting the inner layer of the composite roll, which is a stone material, are for both the inner layer material and the outer layer material. Although it varies depending on the material combination and wall thickness ratio, an example of this will be explained based on Fig. 4. In the case where a hollow roll of Ashikyu cast iron is used as the outer layer material 4 and SC molten steel is used as the inner layer material 10, When the wall thickness ratio of both is 1, the conditions for casting the inner layer are as follows:
When the casting temperature is 1550℃ and the pressure is 1 Y/fit, the outside i
Cast-in joining is possible when the preheating temperature of i is 400°C or higher, and welding of the joining surfaces does not occur when the preheating temperature is lower than 400°C.

[Effects of the present invention]

As mentioned in detail above, the composite roll manufacturing method and manufacturing device of the present invention employs a molten metal pressurization method, so that the boundary between the outer layer material and the inner layer material is more easily welded than the conventional cast-in roll. Promote the phenomenon.

As a result, complete bonding is achieved, allowing high-quality rolls to be produced with less variation in quality.Furthermore, because the molten metal is pressurized, the molten metal yield is 100%. It can be produced in large quantities, and the roll outer layer material is not limited to cast or forged products, and has the effect of allowing various wear-resistant materials to be selected arbitrarily.In addition, with conventional rolls, there is no oxidation of the surface to be cast. In order to prevent this, a surface treatment agent is applied, but the surface treatment agent is interposed on the joint surface, causing gas defects or inclusions.In the present invention, no surface treatment agent is used on the joint surface, and the surface treatment agent is non-oxidized. Since the atmosphere is used, there is an effect that concerns about gas defects or inclusions on the bonding surface are eliminated.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the apparatus of the present invention, and shows a state in which a composite roll manufacturing apparatus is pressurized to reduce melting. Fig. 2 is a detailed view of the seal cover of the same device, and Fig. 3 shows the same device when pouring molten metal. FIG. 4 is a diagram for explaining the conditions for casting the inner layer of the composite roll, which is a stone material, and is a cross-sectional view of the composite roll. 1... Dummy par 2... Dummy par jig 3... Mold 4... Exterior material 5... Dimension adjustment material 6... Seal cover 7... Ar gas blowing nozzle 8... Heating coil 9... Blowout nozzle 10... Inner layer material 11... lI & 11 plunger 12... Air hole 13... Na2 plunger 14... Guide roll 15... - Cooling nozzle 16... Frame 17 ... Ladle 18 ... Top lid 19 ... Tundish 20 ... Sensor sub-agent 1) Post-morning agent Ryo Hagihara −

Claims (2)

[Claims] (1) When manufacturing a composite roll to be molded on the inner surface of a cylindrical integral mold, the portion corresponding to the outer layer of the composite roll is formed into a hollow roll shape in advance, and the hollow roll is placed on the inner surface of the mold. After that, the composite roll is preheated in a non-oxidizing atmosphere, then molten metal such as cast steel is poured into the hollow part of the hollow roll, the poured part is pressurized with a press, and then cooled. Method. (2) A cylindrical integral mold for molding and pressurizing the composite roll and its preheating device, a dummy bar for holding the molten metal, and a press for pressurizing the molten metal that becomes the core material of the composite roll;
Furthermore, it shall consist of an oxidation-free device for maintaining the non-oxidation state of the joint surface of the cast insert during preheating of the mold, a sensor for detecting molten metal, and a cooling zone for cooling the casting after solidification under pressure. Composite roll manufacturing equipment featuring: