JPS6082611A - Skid rail compounded with ceramic - Google Patents

Abstract

PURPOSE:To avoid occurrence of crack in the heat resistant ceramic constructing the upper surface contacting with an object to be heated of the titled skid rail by using heat resistant alloy in the part where the object to be heated contacts in the first stage. CONSTITUTION:A skid rail 1 is constructed on a steel rail base 3 welded to a pipe with clamping fixtures 4 made of superhigh heat resistant cast steel providing a partly heat insulating space 8 interposed between the base material 3 and fixing a ceramic member 6 inserting a heat insulative refractory 5 therebetween. Ni-Cr steel contg. >=ca. 11% Cr, or Fe base heat resistant alloy is used for the material of the fixture. The fixture at the back end part 41 of the rail contacting with the object to be heated in the first stage is constituted of said heat resistant alloy. The face of the fixture 6 is inclined by ca. 30 deg. to the face of the rail with an inclined face 411, forming then a parallel face 412 and is transferred to the ceramic member 6. By this constitution, the impact on the ceramic member 6 due to contact with the object to be heated is prevented and occurrence of crack is prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to improvements in the skid rails of continuous heating furnaces, particularly single furnaces.

A composite skid rail using heat-resistant ceramics on the top surface of the skid rail has been proposed with the aim of improving thermal efficiency in continuous heating furnaces and preventing the occurrence of skid marks on objects to be heated, and has come into practical use. Typical heat-resistant ceramics include Si3N4, S1alon, and S;cyi.

However, the use of ceramics poses new problems, including the fact that the object to be heated slides on the skid rails for the Butsher furnace, which creates complex stresses on the rails.
It has been experienced that ceramic members are prone to cracking. If the rails are damaged, there is no point in using heat-resistant ceramics, which have much better heat resistance and wear resistance than conventional heat-resistant cast steel.

The inventors of the present invention discovered that cracks in the ceramic members of conventional composite unit rails originate from the rear end of the rail where the object to be heated first comes into contact with and covers the rail, and obtained the present invention as an improvement measure. This is what we propose.

As shown in the drawings, the ceramic composite skid rail of the present invention is a skid rail for a pusher furnace in which a heat-resistant ceramic member 6 is used on the upper surface that contacts the object to be heated. This is a ceramic composite skid rail 1 characterized in that a heat-resistant alloy is used for the rear end portion 41 of the rail.

In the preferred embodiment illustrated in the drawings, this skid rail 1 has a steel rail base material 3 welded to a pipe 2 through which a cooling medium passes, and a ceramic member fixing fitting 4 made of ultra-heat-resistant fJI, fl on which a steel rail base material 3 is welded. is attached between the rail base materials 3 through a partial heat insulating space 8, and a ceramic member 6 is fixed with a heat insulating refractory 5 sandwiched therebetween.

This fixing metal fitting is usually exposed outside the kitstable refractory 7 that covers the skid rail body, so the J:Una carbon steel used in conventional ceramic member fixing metal fittings is insufficient, and the Or Containing 11% or more N1, c
o or Fe-based heat-resistant alloys must be used.
Super heat-resistant cast steel whose main components are 21%Ni-28%Cr-23%CO is preferred. However, since such steel has poorer weldability than carbon steel, a carbon steel stopper 9 is welded to the rail base material 3 and is attached.

The heat insulating refractory 5 is, for example, a 20 mm thick A-type 203-
8! A heat insulating brick is used, and a ceramic member 6, for example, 3i 3N4 material with a thickness of 30 mm is used.

The rear end 41 of the rail, which comes into contact with the object to be heated first, is made of the above-mentioned heat-resistant alloy, and is tilted at an angle of 30° to the rail surface, for example.
It is preferable that the shape is such that it passes through the inclined surface 411, curves toward the parallel surface /112, and transitions to the ceramic member 6.

When manufacturing this rail rear end portion 41, it is preferable that the height of the heat-resistant alloy surface 412 is slightly higher than the height of the ceramic member 6 surface, as shown in the figure. It has been found that an appropriate height difference varies from case to case, but is typically in the range of 0.5 to 8 mm.

This height difference prevents impact caused by contact of the heated object to the ceramic member and prevents cracking. With use, this part deforms relatively quickly and reaches a height that is not much different from that of the ceramic member, but depending on subsequent use, it does not dent and deform, and continues to play the role of protecting the ceramic member.

Providing such a height difference is also advantageous in that it eliminates the need for increased dimensional accuracy when manufacturing the skin trail.

[Brief explanation of drawings]

All of the drawings are for explaining preferred examples of the ceramic composite skid rail of the present invention.
The figure is a vertical cross-sectional view, and Figure 2 is a horizontal width i-plane view in the position of Figure 1. ...Rail base material 4...Heat-resistant alloy fixing fittings 5...
...Insulating refractory 6...Ceramics member 41...
... Rear end 411 ... Slanted surface 412 ...
・・・Parallel plane 8・・・・・・Insulating space special '[Applicant: 1S! Suko Co., Ltd. Agent Patent Attorney Su r'i So Fuga 1 Figure 1-A Fang 2 Figure

Claims (1)

[Claims] (1) In a skid rail for a butcher furnace that uses a heat-resistant ceramic member on the upper surface that comes into contact with the object to be heated, a heat-resistant alloy is used at the rear upper end of the rail where the object to be heated first comes into contact. The Hiramix composite skid rail is characterized by: 2) Attach a metal Reramix member fixing fitting, at least a part of which is made of ultra-heat-resistant cast steel, on top of the rail base via a partial insulation space, so that the rear end of the rail formed by the fixing fitting forms an inclined surface. The skid rail according to claim 1, wherein the skid rail has a shape that becomes a parallel surface and transitions to a ceramic member. (3) Claim 1 or 2 in which the height of the surface of the heat-resistant alloy is higher than that of the surface of the heat-resistant ceramic.
Section skid rail.