JPS634904B2 - - 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 consisting of Co and unavoidable impurities. Co-based alloy sheet materials 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 problem] Therefore, from the above-mentioned viewpoint, the present inventors focused on the above-mentioned conventional Co-based alloy sheet material and conducted research 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. 700 to 1000 when stress is applied to the base alloy plate material between surface plates.
When subjected to aging treatment at a temperature of It now has a structure precipitated within the crystal grains, and the secondary carbides precipitated within this crystal powder are fine particles with a diameter of 1 μm or less, so the hardness within the crystal grains is lower than that of conventional Co-based alloy sheets. Then, the one with a Bitkers hardness of about 250,
300, which significantly improves wear resistance.Furthermore, if there is any "warpage" in the Co substrate material after the solution treatment, it not only corrects this, but also improves wear resistance. It was found that this warping acts to promote the precipitation of the secondary carbides. 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 consisting of Co and unavoidable impurities, and was subjected to solution treatment under normal conditions.
The Co-based alloy plate material is further aged between 700 and 1000 degrees Celsius with stress placed between surface plates made of heat-resistant steel or stainless steel. It has a structure in which primary carbides are dispersed, secondary carbides are dispersed at grain boundaries, and secondary carbides with a diameter of 1 μm or less are further dispersed within the crystal grains. This method is characterized by a method for producing a Co-based alloy sheet material with extremely high wear resistance. Next, the reason why the composition and aging treatment temperature of the Co-based alloy sheet material are limited as described above in the method of the present invention 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 cannot be obtained; on the other hand, if the content exceeds 20%, the plastic workability will decrease and the plate material will tend to become brittle. The amount was set at 2-20%. (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 Aging treatment temperature If the temperature is less than 700°C, 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℃. Note that there are no particular restrictions on the added stress and holding time during aging treatment, and they may be determined as appropriate depending on the composition and thickness of the Co-based alloy sheet material, as well as the degree of warpage.
100-500g/cm ² , retention time 15-20 minutes
All you have to do is keep an eye on the time. [Example] Next, the method of the present invention will be specifically explained with reference to 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: 90 mmφ x length: 350 mm. to, 1200
Hot forging at temperatures of ~1000℃, as well as 1200~1000
A hot-rolled plate with a thickness of 2 mm was obtained by hot rolling at ℃, and this hot-rolled plate was further held at a temperature of 1200℃ for 30 minutes, then subjected to solution treatment under air cooling conditions, and then this solution treatment Rear width: 200mm x Thickness: 2mm x Length: 300mm: 3 boards, Width: 500mm
Heat-resistant steel lower surface plate with dimensions of mm x thickness: 50 mm x length: 1000 mm, and width: 500 mm x thickness: 100 mm
× Length: Between the upper surface plates made of heat-resistant steel with dimensions of 1000 mm

【table】

〔Effect of the invention〕

From the results shown in Table 1, it can be seen that the plates manufactured by the method of the present invention all have a structure in which fine secondary carbides are precipitated within the crystal grains.
It is clear that the plate material exhibits superior wear resistance compared to the as-solution-treated plate material, which has a structure in which subcarbides are precipitated only at grain boundaries. 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 (weight%). After solution treatment is performed under normal conditions, this is determined. By performing aging treatment at a temperature of 700 to 1000℃ with stress applied between the discs, the structure is changed so that primary carbides are dispersed in the matrix and secondary carbides are dispersed at the grain boundaries. And within the crystal grains, there is a diameter of 1 μm or less.
A method for producing a Co-based alloy sheet material with excellent wear resistance characterized by a structure in which subcarbides are dispersed. 2 C: 0.05-2%, one or two of W and Mo: 2-20
%, Cr: 15-35%, and further contains one or two of Ni and Fe: 1-25
%, with the remainder consisting of Co and unavoidable impurities (weight %) is subjected to solution treatment under normal conditions, and then subjected to stress by sandwiching it between surface plates. By aging treatment at a temperature of 700 to 1000°C, the structure is changed such that primary carbides are dispersed in the matrix, secondary carbides are dispersed in the grain boundaries, and the grains have a diameter of: 2 less than 1μm
A method for producing a Co-based alloy sheet material with excellent wear resistance characterized by a structure in which subcarbides are dispersed.