JPH06142893A - Manufacture of complex calender roll - Google Patents

Abstract

PURPOSE:To provide a manufacturing method for complex calender roll, in which an outer peripheral surface is hardly stripped off from a core member and thick and close wear resistant layer is easily obtd. CONSTITUTION:While dipping the outer peripheral surface of the cylindrical core member 1 formed of a high strength steel material into bath 2 of a matrix metal, the core member 1 is rotated and a high hardness ceramic particles are supplied to a position near the outer peripheral surface of the core member in the bath on the rotating-out side of the core member 1 from the metal bath. While continuously forming the molten metal layer 5 mixed with the ceramic particles on the outer peripheral surface of the core member 1, the layer 5 is cooled and a wear resistant layer 6 with the ceramic particles embedded in the matrix metal is deposited and formed integrally on the outer peripheral surface of the core member 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a composite calender roll which is capable of forming a dense and thick wear-resistant layer on the outer peripheral surface of a core member.

[0002]

2. Description of the Related Art A calendar roll for papermaking has hitherto been manufactured as a single roll by using a chilled roll material. The microstructure consisted of relatively soft pearlite and mesh cementite surrounding the pearlite, and the hardness was about Hs75, and some good wear resistance was obtained. However, it was inferior in surface roughening resistance, crack resistance, and breakage resistance, and the abrasion resistance was not sufficient.

Therefore, as disclosed in Japanese Patent Laid-Open No. 01-150667, a composite calender in which a sprayed layer of carbide cermet containing WC as a main component is formed as an abrasion resistant layer on the outer peripheral surface of a core member made of cast iron material. Rolls are now used.

[0004]

However, since the wear-resistant layer of the calender roll is a sprayed layer and is porous, there is a limit in improving the surface roughness. Further, it is difficult to form a thick sprayed layer, and since the sprayed layer is only physically attached to the surface of the core member, there is a problem that it is easily peeled off, and durability is poor.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for producing a composite calender roll which is difficult to peel off and which can easily obtain a thick and dense wear resistant layer.

[0006]

The method for producing a composite calender roll of the present invention is a method for manufacturing a composite calender roll by immersing the outer peripheral surface of a cylindrical core member formed of a tough steel material in a metal bath of matrix metal. By rotating, the high hardness ceramic particles are supplied to the vicinity of the outer peripheral surface of the core member in the bath on the side where the core member comes out of the metal bath, and the molten metal layer mixed with the ceramic particles is continuously applied to the outer peripheral surface of the core member. It is cooled while being formed, and a wear resistant layer having ceramic particles embedded in a matrix metal is integrally formed by welding on the outer peripheral surface of the core member.

[0007]

When the core member is rotated while the outer peripheral surface of the core member is immersed in the metal bath of the matrix metal, the molten metal in the bath flows so as to be dragged to the outer peripheral surface of the core member due to its viscosity.
When the outer peripheral surface of the core member goes out of the metal bath, it is scooped up on the outer peripheral surface to form a layer of molten metal having a constant thickness.
At this time, if high hardness ceramic particles are supplied to the vicinity of the outer peripheral surface of the core member in the bath on the side where the core member goes out of the metal bath,
The ceramic particles are easily mixed in the molten metal flow dragged by the outer peripheral surface of the core member, and the molten metal layer formed on the outer peripheral surface of the core member is mixed with the ceramic particles. This molten metal layer is deprived of heat by the core member during rotation of the core member and solidifies to become a wear-resistant layer in which ceramic particles are embedded in the matrix metal. Since the wear resistant layer is bonded to the surface of the core member through the thin alloy layer, it is difficult to peel it off. By continuously rotating the core member on which the abrasion resistant layer is formed and continuously forming a new abrasion resistant layer on the abrasion resistant layer, an abrasion resistant layer having an arbitrary thickness can be obtained.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the present invention, in which a core member 1 which constitutes a barrel core portion of a calender roll is rotatably supported horizontally, and an outer peripheral surface thereof is a metal bath 2 of a matrix metal. Is soaked in. The core member 1 has a diameter of 1 m.
It has a cylindrical shape with a wall thickness of about 200 mm, and a toughness steel material such as carbon steel for mechanical structure such as SC material or low alloy steel for mechanical structure such as SCM material is used as the material. Since the wall thickness is large, the core member 1 is usually manufactured by the centrifugal casting method.
Cooling water 3 is supplied to the inside of the core member 1 and cooled to a predetermined temperature. The core member 1 is generally subjected to degreasing, pickling, washing with water, and flux treatment before being partially immersed in the metal bath 2, as in the case of hot dipping.

As the matrix metal forming the metal bath 2, a high strength material having excellent corrosion resistance and heat resistance, such as WC-Co metal, Ni-base alloy and high Cr cast iron, is suitable. The temperature of the molten metal in the metal bath 2 is usually 100 to 20 above the melting point.
It is maintained at a high temperature of about 0 ° C. The metal bath 2 is provided with a lance 4 for discharging high hardness ceramic particles. The lance 4 is made of a heat-resistant material, and its discharge port is opened upward near the lower portion of the outer peripheral surface on the side where the core member 1 turns around from the metal bath 2. The ceramic particles are supplied to the lance 4 together with an inert gas such as argon gas, are discharged from the discharge port, and are mixed in the flow of the molten metal flowing while being dragged by the outer peripheral surface of the core member 1. As the above-mentioned ceramics, any ceramic having a high degree of affinity with a matrix metal and having a high hardness which does not decompose even when contacted with a molten matrix metal can be used. For example, Al ₂ O ₃ , SiO ₂ , ZrO ₂ , W
C or SiC can be used. However, those having a smaller specific gravity than the matrix metal (for example, Al
₂ O ₃ ) is preferable because it easily floats upward and easily mixes with the molten metal flow flowing along the outer peripheral surface of the core member 1. The particle size of the ceramic powder is preferably about several tens of μm. Even if such fine powder is used, according to the present invention, the ceramic powder is easily mixed because it is caught in the molten metal flow flowing along the outer surface of the core member 1.

Ceramic powder is supplied to the lance 4,
When the core member 1 is rotated in the discharged state, when the core member 1 goes out of the metal bath 2, a molten metal layer 5 mixed with ceramic powder is continuously adhered and formed on the outer peripheral surface thereof, and the core member 1 is rotated during rotation. The heat-resistant layer 6 is deprived of heat and cooled to form the wear-resistant layer 6 having a constant thickness. Although the thickness of the wear resistant layer 6 varies depending on the viscosity of the molten matrix metal, the core member 1
It can be controlled by the cooling temperature and the rotation speed. Further, the wear resistant layer 6 formed on the outer peripheral surface of the core member 1
By continuously laminating a new abrasion resistant layer on the above, an abrasion resistant layer having a desired thickness can be obtained.

The wear resistant layer is preferably formed in a vacuum atmosphere or an inert gas atmosphere. By carrying out in such an atmosphere, surface oxidation of the wear resistant layer can be prevented.

[0012]

As described above, according to the method for manufacturing a composite calender roll of the present invention, high hardness ceramic particles are supplied to the vicinity of the outer peripheral surface of the core member in the bath on the side where the core member turns out of the metal bath. Therefore, the molten metal layer mixed with the ceramic particles can be continuously formed on the outer peripheral surface of the core member, and the high hardness ceramic particles are embedded in the matrix metal on the outer peripheral surface of the core member by solidification of the molten metal layer. The wear resistant layer thus formed can be integrally formed by welding. Since this wear-resistant layer is welded to the outer peripheral surface of the core member, it is hard to peel off and is dense, and a layer having a large layer thickness can be easily formed and is excellent in durability.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an example of an implementation point of the present invention.

[Explanation of symbols]

 1 core member 2 metal bath 4 lance 5 molten metal layer 6 wear-resistant layer

Claims (1)

[Claims] 1. A bath on the side where the core member turns out of the metal bath while the outer periphery of a cylindrical core member made of a tough steel is immersed in a metal bath of matrix metal while the core member is rotated. Of high hardness ceramic particles in the vicinity of the outer peripheral surface of the core member, the molten metal layer mixed with the ceramic particles is continuously formed on the outer peripheral surface of the core member and cooled, and the core metal outer peripheral surface is cooled in the matrix metal. A method for manufacturing a composite calender roll, characterized in that a wear-resistant layer having ceramic particles embedded therein is integrally formed by welding.