JPH0732496U - Austemper furnace shaker hearth - Google Patents

Abstract

(57) [Summary] [Purpose] In an austempering furnace with a shaker hearth, the durability of the transfer surface of the shaker hearth, which deteriorates due to scale generation, corrosion, etc., at all times under high temperature, is improved and reliability of heat treatment is improved. Security and productivity. [Structure] A ceramic coating layer having wear resistance and heat resistance due to explosive spraying is applied to a conveying surface on which a charging member of a shaker hearth is oscillatingly fed.

Description

[Detailed Description of the Invention] (Industrial field of application) This invention is an austemper furnace with a shaker hearth that can be rock-feeded at high temperature all the time while maintaining the surface smoothness and without deforming the charging material. It relates to a shaker hearth with improved durability.

(Prior Art) Conventionally, in an austempering furnace provided with a shaker hearth, for example, a charging material for a spring, which is installed in a furnace in an oxygen-free atmosphere and is constantly charged for heat treatment at a high temperature of 850 ° C. Place it on a shaker hearth that is repeatedly rocked via a cam mechanism, and after a certain heating time while rocking and feeding, put it in a 360-390 ° C salt bath from the tip of the hearth and keep it isothermal. In the case of heat treatment, the surface of the shaker hearth transfer path is constantly exposed to high temperature, and further, due to the deposition of salt vapor, it is deteriorated due to scale generation, corrosion, etc., resulting in a fluffy surface condition, increasing friction, and the charging material is not sent smoothly. However, since it is in a heated state, there is a problem in that quality of the charging material varies due to deformation of the charging material and fluctuations in the passage time of the charging material in the furnace.

 Therefore, we have taken measures such as using rolled stainless steel or heat-resistant cast steel as the material for the shaker hearth, and applying a protective coating on the surface of the hearth in the shape of a flap to polish and repair it. The current situation is that the effect of improvement has not been achieved.

(Problems to be solved by the invention) This invention is to solve the problems caused by the lack of durability of the transfer surface of the shaker hearth as described above. Has an excellent durability and durability, and provides an appropriate protective coating that does not cause defects such as deformation to the hearth when applying it, and reliability of heat treatment by an austempering furnace equipped with a shaker hearth It aims to improve productivity and productivity.

(Means for Solving the Problem) In order to achieve the above-mentioned object, the present invention uses an explosive melt as a protective film to be applied to a conveying surface on which a charging member of a shaker hearth of an austempering furnace is placed and swing-fed. The results of solving the problems were achieved by applying ceramic coatings such as chromium carbide and alumina-based thermite, which have excellent wear resistance and heat resistance due to irradiation. Ceramic coating, which is applied as a protective film, is a widely known method, and in general, spraying is a method in which ceramic powder or a sintered body is heated and melted by a plasma jet or an oxygen acetylene flame and fine droplets are sprayed on the substrate surface. As a method that meets the purpose of ceramic coating, the method using explosive spraying is the most suitable means for shaker hearth. That is, as the prior art, for example, the ceramic layer in the concrete form made of ceramics according to Japanese Utility Model Publication No. 62-31548 has extremely high hardness and strength, and is firmly welded to the outer plate and is probably porous. A coating that has good releasability from a concrete wall for pouring due to the penetration of a mold release agent is sprayed by a plasma spray system at a high temperature of 10,000 ° C or higher as a heat source at almost the same speed as the sonic velocity. In the explosive spraying of the present invention, a relatively thin heat source of about 3,300 ° C. forms a dense film on the material at a speed twice as high as the sound velocity, so that there is no thermal deformation of the shaker hearth and excellent wear resistance. It has been proved that the required surface roughness can be maintained for a long time under severe conditions in the furnace.

(Operation) Since the present invention has the above-mentioned configuration, it is possible to obtain the operation effect of a durable shaker hearth capable of maintaining the surface smoothness for a long time at all times and accurately swinging and feeding the charging material. You can

 That is, the smoothness of the hearth surface has a great influence on the finish of the product in order to secure the quality of the charging material that is heat-treated in the shaker hearth austempering furnace, and the problem of the shape and dimension defects of the specially processed product, etc. Regarding the trouble that occurred in the function of the shaker hearth due to the deterioration due to the oxidation of the surface of the hearth, the burning of the scale, etc., the application of the ceramic coating by explosive melting is effective and the durability is significantly increased. Since it was possible to improve the reliability and productivity of heat treatment using an austempering furnace, it has the effect of solving the problems.

(Embodiment) An embodiment of the present invention will be described below with reference to the drawings.

 1 to 3 show the attached state of the shaker hearth 1 of the austempering furnace F of the present invention. The rear end 4 of the austempering furnace F is supported in a cantilever manner in the horizontal direction via the drive arm K, and the aft end of the austempering furnace F is opened in front of the charging section B. The insert member S to be heat-treated from above the charging part B inserted in the non-oxidizing atmosphere furnace A provided in the above is placed as the conveying surface 2 with the groove bottom having the groove shape shown in FIG. It is repeatedly rocked back and forth in the horizontal direction by an actuating spring E which is biased via a beveled cam Ca directly connected to a drive shaft D mounted in parallel therewith under the hearth 1 and a driven beveled cam Cb facing the same axis. A shaker shock is applied at the returning position of the spring E biased by the shaker hearth 1 supported by the drive arm K attached to the boss Bc for the follower cam so that the device mounted on the transport surface 2 can be moved. The insertion member S is guided by the groove walls 5 on both sides. Sequentially, while being oscillatingly fed into the atmosphere furnace A, after a predetermined heating time of 850 ° C., it was dropped from the tip portion 6 and immersed in a salt bath SB opening directly below, isothermal at 360 ° to 390 ° C. The held charging member S is carried out of the furnace via the belt conveyor H. On the carrying surface 2 of the shaker hearth 1, a ceramic coating layer 3 having a composition of cobalt, chromium, tantalum, and aluminum as a main component and alumina as a powder material for ceramic coating is applied by explosive spraying with a detonation gun. As a feature of explosive spraying, the combustion gas generated by the explosion of the mixed gas in the barrel of the detonation gun turns the ceramic material into a semi-molten state and collides high-speed particles with twice the speed of sound with the transport surface 2 of the shaker hearth 1. A non-metallurgical bond that does not damage the material side realizes high adhesion force due to high-speed particles, and excellent interparticle bond force during coating formation, resulting in high coating density and a strong and smooth coating surface. can get. Explosive spraying, which has a layered structure of fine flat particles, has higher bending strength and elastic modulus than other spraying methods such as plasma spraying, and has great followability to base metal deformation. Therefore, the shaker hearth 1 is capable of maintaining the smoothness for a long period of time under harsh conditions and obtaining reliability in securing the quality of the charging member S. For example, as shown in Fig. 4, the leaf spring bent to one side and bent has a dimensional variation of the length l of the opening, so there is a track record of completely eliminating the trouble of sorting after heat treatment. .

 (Effect of the Invention) Since the present invention has the above-mentioned configuration, it has the following advantages.

(1) Prevents oxidation of the transfer surface of the shaker hearth, prevents seizure of scales, etc. over a long period of time, and improves the wear resistance of the surface, which eliminates the need for periodic polishing of the surface, thus providing an economical effect. Is big.

(2) Since the smoothness of the hearth surface is maintained, the quality of the heat-treated product is stable and the productivity can be increased by a reliable heat-treatment furnace.

[Brief description of drawings]

FIG. 1 is a front view for explaining a mounting state of a shaker hearth of an austempering furnace of the present invention, and FIG. 2 is a plan view thereof.
FIG. 3 is a partial explanatory view of the charging part, FIG. 4 (a) is a sectional view taken along the line AA in FIG. 2, and (b) is a schematic view of the charging member shown in FIG. (Explanation of symbols of main parts) 1 ... Shaker hearth of austempering furnace 2 ... Conveying surface 3 ... Ceramic coating layer F ... Austempering furnace S ... Charging member

Claims (1)

[Scope of utility model registration request] In an austempering furnace (F) having a shaker hearth (1), a conveying surface formed on a groove bottom having a groove shape in section of a shaker hearth (1) on which a charging member (S) is placed and which is repeatedly oscillated. A shaker hearth for an austempering furnace, characterized in that (2) is provided with a wear-resistant and heat-resistant ceramic coating layer (3) due to explosive spraying.