JPS634905B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for producing a Co-based alloy plate material that has excellent wear resistance and heat resistance. [Prior Art] In general, excellent wear resistance and heat resistance are required for manufacturing chain saw guides, saw teeth for woodworking, light metal and alloy cutting, and steam turbine blades. Various Co
Base alloy plate material is used. In addition, one of these various Co-based alloy sheet materials
In terms of weight% (hereinafter % indicates weight%), C: 0.05 to 2%, one or two of W and Mo: 2 to 20
%, Cr: 15 to 35%, and if necessary, one or two of Ni and Fe: 1 to 25%, with the remainder being Co and unavoidable impurities. Co-based alloy sheet materials having the following properties are widely known. This Co-based alloy sheet material is usually made into a sheet material having a thickness of approximately 1 to 4 mm by subjecting the ingot after casting to blooming forging, blooming rolling, hot rolling, and cold rolling. It is manufactured by solution treatment at a temperature of ~1250°C, and is put into practical use in this state. [Problems to be solved by the invention] However, in recent years, there has been a demand for higher speeds and higher performance even in the above-mentioned fields of application, and with this, the above-mentioned conventional Co-based alloy sheet materials have Further improvement in wear resistance is desired. [Means for Solving the Problems] Therefore, from the viewpoints described above, the present inventors focused on the above-mentioned conventional Co-based alloy sheet material and conducted research in order to further improve its wear resistance. As a result, after solution treatment, the conventional Co-based alloy sheet material described above has a structure in which primary carbides are dispersed in the matrix and secondary carbides are precipitated only at grain boundaries. If a cold permanent strain of 0.1 to 10% is applied to the base alloy plate material using a stretcher or the like to generate slip lines within the crystal grains, then aging treatment is performed at a temperature of 700 to 1000°C in this state. ,
Fine secondary carbides with a diameter of 1 μm or less begin to precipitate on the slip lines, and as a result, primary carbides exist in the matrix and secondary carbides are dispersed at grain boundaries. In a Co-based alloy sheet material having a structure in which secondary carbides are precipitated within the crystal grains, the hardness within the grains is approximately 250 in terms of Vickers hardness in the conventional Co-based alloy sheet material, but
Since it will improve to over 300,
They found that it exhibits extremely good wear resistance. Therefore, this invention was made based on the above findings, and includes: C: 0.05 to 2%, one or two of W and Mo: 2 to 20%.
%, Cr: 15 to 35%, and if necessary, one or two of Ni and Fe: 1 to 25%, with the remainder being Co and unavoidable impurities. and solution treatment under normal conditions.
By subjecting the Co-based alloy sheet material to a cold permanent strain of 0.1 to 10% and subjecting it to aging treatment at a temperature of 700 to 1000℃, primary carbides are added to the matrix and grain boundaries are formed. This method is characterized by a method for producing a Co-based alloy sheet material with extremely excellent wear resistance, which has a structure in which secondary carbides are dispersed in the crystal grains and secondary carbides with a diameter of 1 μm or less are dispersed in the crystal grains. . Next, in the method of the present invention, the reason why the composition, percentage of permanent strain, and aging treatment temperature of the Co-based alloy sheet material are limited as described above will be explained. A Component composition (a) C C component has the effect of forming carbide and improving wear resistance, but if its content is 0.05
If the content is less than 2%, the precipitation of secondary carbides will be insufficient, making it impossible to secure the desired wear resistance.On the other hand, if the content exceeds 2%, plastic working will become difficult. quantity
It was set at 0.05-2%. (b) W and Mo These components partially form a solid solution in the base material and have the effect of strengthening it and forming carbides to improve wear resistance, but the content is 2%. If the content is less than 20%, the desired effect will not be obtained, while if the content exceeds 20%, the plastic workability will deteriorate, and
Since the plate material tends to become brittle, its content was set at 2 to 20%. (c) Cr The Cr component has the effect of improving heat resistance by forming a solid solution in the base material, as well as improving wear resistance by forming carbide, but the content is 15%.
If it is less than the desired effect, the desired effect cannot be obtained.
On the other hand, if the content exceeds 35%, embrittlement phases such as σ phase will appear and plastic workability and ductility will decrease.
Its content was set at 15-35%. (d) Ni and Fe These components dissolve in solid solution in the base material and have the effect of improving ductility and plastic workability, so they may be included as necessary when these properties are particularly required. , its content is 1%
If the content is less than 25%, the desired effect of improving the above action cannot be obtained, while if the content exceeds 25%, the wear resistance will be significantly lowered, so the content is set at 1 to 25%. B Permanent set ratio If the ratio is less than 0.1%, the generation of slip lines within the crystal grains is insufficient, and as a result, the precipitation of secondary carbides after aging treatment is also insufficient, resulting in the desired wear resistance. On the other hand, if the ratio exceeds 10%, work hardening will be significant and the ductility of the plate material will rapidly decrease.
The percentage was set at 0.1-10%. C Aging treatment temperature If the temperature is less than 700℃, fine secondary carbides cannot be produced sufficiently within the crystal grains.
On the other hand, if the temperature exceeds 1000℃, the secondary carbides will become coarser and the desired wear resistance cannot be achieved.
The temperature was set at 700-1000℃. EXAMPLES Next, the method of the present invention will be specifically explained using examples. Molten Co-based alloys having the respective compositions shown in Table 1 are prepared using a normal melting method, and cast into ingots with dimensions of diameter: 90mmφ x length: 350mm. to, 1200
Hot forging at temperatures of ~1000℃, as well as 1200~1000
℃ to obtain a hot-rolled plate with a thickness of 2 mm, and this hot-rolled plate was held at a temperature of 1200℃ for 30 minutes, then subjected to solution treatment under air cooling conditions. An Instron type 10 ton tensile tester was used as a substitute for a stretcher to permanently test the plate material with dimensions of width: 40 mm x thickness: 2 mm x length: 300 mm after chemical treatment at the proportions shown in Table 1. After applying strain, aging treatment is performed in the atmosphere at the temperature shown in Table 1 (after holding for 1 hour, air cooling)
Methods 1 to 22 of the present invention were carried out by performing the following steps. Next, the results obtained by the methods 1 to 22 of the present invention are as follows.

【table】

〔Effect of the invention〕

From the results shown in Table 1, the plates of the present invention manufactured by the method of the present invention all have a structure in which fine secondary carbides are precipitated within the grains, so the secondary carbides are present at the grain boundaries. It is clear that this material exhibits superior wear resistance compared to the conventional sheet material that has been solution-treated and has a precipitated structure. As described above, according to the method of the present invention, it is possible to produce a Co-based alloy sheet material having a structure in which fine secondary carbides with a diameter of 1 μm or less are precipitated within the crystal grains, and the precipitation of the secondary carbides is As a result, the hardness of the crystal grain itself is significantly improved.
The Co-based alloy sheet material has industrially useful effects such as extremely excellent wear resistance.

Claims (1)

[Claims] 1 C: 0.05 to 2%, one or two of W and Mo: 2 to 20
%, Cr: 15 to 35%, and the remainder is Co and unavoidable impurities (wt%). After solution treatment is carried out under normal conditions, this is cooled. Between
Apply a permanent strain of 0.1-10%, followed by 700-1000
By aging at a temperature of
Subcarbide is dispersed and inside the crystal grains diameter: 1μm
A method for producing a Co-based alloy sheet material having excellent wear resistance, characterized by having a structure in which the following secondary carbides are dispersed. 2 C: 0.05-2%, one or two of W and Mo: 2-20
%, Cr: 15 to 35%, and further contains one or two of Ni and Fe: 1 to 25%, with the remainder being Co and inevitable impurities (weight %) After applying solution treatment under normal conditions to a Co-based alloy sheet material with
Apply a permanent strain of 0.1-10%, followed by 700-1000
By aging at a temperature of
Subcarbide is dispersed and inside the crystal grains diameter: 1μm
A method for producing a Co-based alloy sheet material having excellent wear resistance, characterized by having a structure in which the following secondary carbides are dispersed.