Method for controlling sintering deformation of high-cobalt hard alloy roll collar
Through the method of sintering and landfilling alumina, the problem of falling deformation during sintering of high-cobalt cemented carbide roller ring is solved, and the effect of reducing sintering deformation, controlling margin and improving product qualification rate is achieved.
Patent Information
- Application Number
- CN202411429923.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-14
- Publication Date
- 2025-02-18
AI Technical Summary
The high-cobalt cemented carbide roller ring is prone to falling and deformation during the sintering process, resulting in the taper of the outer circle and inner holes, and the inner holes and heights, resulting in the scrapping of the product.
The blank shrinkage was carried out by two sintering methods. The first sintering was 1300°C to complete the blank shrinkage. Before the second sintering, the graphite ring was circumscribed outside the roller ring, the alumina powder was filled and the pressure sintered to 1360-1380°C.
It effectively prevents the roll ring from falling and deformation, reduces sintering deformation, controls the margin, improves the product pass rate, and reduces production costs.
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of cemented carbide roller ring manufacturing, and in particular to a method for controlling the sintering deformation of a high-cobalt cemented carbide roller ring. Background Art
[0002] High cobalt cemented carbide roller ring refers to a cemented carbide roller ring with a cobalt content of more than 25%, which is mostly used for rolling threaded finished products. The sintering process of the roller ring is generally completed at 1360-1400℃, and it is easy to deform during high temperature and pressure sintering. The roller ring is prone to falling and deformation at high temperatures of 1360-1400℃. For example, the blank size is φ380*φ260*120, and the designed size after sintering is φ385*φ255*125, and the actual size is φ382 / 388*φ260 / 258*119. The deformation causes the outer circle and inner hole of the roller ring to have a taper, and there is no margin for the inner hole and height, which eventually leads to product scrapping. Summary of the invention
[0003] In view of the deficiencies in the prior art, the present invention provides a method for controlling the sintering deformation of a high-cobalt cemented carbide roller ring, thereby solving the problem that the roller ring is prone to falling and deformation during sintering.
[0004] To achieve the above object, the present invention provides the following technical solution: a method for controlling the sintering deformation of a high-cobalt cemented carbide roller ring, characterized in that the blank is sintered twice; The first sintering, wax removal and vacuum sintering to 1300℃ to complete the blank shrinkage, as follows: 1) Raise the temperature to 380℃ at a rate of 2-5℃ / min, keep warm for 1-2h, and remove wax for sintering; 2) Raise the temperature to 700℃ at a rate of 2-5℃ / min, keep warm for 0.5-1h, and remove wax for sintering; 3) Raise the temperature to 1300℃ at a rate of 2-5℃ / min, keep warm for 1-2h, and sinter in vacuum.
[0005] The second sintering, before sintering, first put a graphite ring on the outer circle of the roller ring, the gap between the outer circle of the roller ring and the graphite ring is about 5mm, then fill the gap between the outer circle of the roller ring and the inner hole of the graphite ring, and the inner hole of the roller ring with alumina powder and press it, and then pressurize and sinter to 1360~1380℃, as follows: 1) Raise the temperature to 600℃ at a rate of 2-5℃ / min, keep warm for 1-2h, and sinter in vacuum; 2) Raise the temperature to 1360℃ at a rate of 2-5℃ / min, keep warm for 0.5-1h, and apply pressure to 3-5Mpa.
[0006] Preferably, during the first sintering, the vacuum degree is 50 Pa, the heating rate is 3 ° C / min, and the temperature is kept at 1300 ° C for 1 hour. After that, the sintering furnace starts the fast cooling mode, cools to 80 ° C, opens the furnace door, and takes out the product.
[0007] Preferably, during the second sintering, the sintering is performed at 1360° C. in an argon atmosphere for 1 hour.
[0008] Compared with the prior art, the present invention has the following advantages and effects: the secondary sintering and alumina landfilling method can effectively prevent the roller ring from falling and deforming, reduce the sintering deformation of the roller ring, control the margin, improve the product qualification rate, and reduce the production cost. BRIEF DESCRIPTION OF THE DRAWINGS DETAILED DESCRIPTION
[0010] The technical solutions in the embodiments of the present invention are clearly and completely described below. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work are within the scope of protection of the present invention.
[0011] Example 1.
[0012] This embodiment provides a method for controlling the sintering deformation of a high-cobalt cemented carbide roller ring, wherein the blank is sintered twice; The first sintering, wax removal and vacuum sintering to 1300℃ to complete the blank shrinkage, as follows: 1) Raise the temperature to 380℃ at a rate of 2-5℃ / min, keep warm for 1-2h, and remove wax for sintering; 2) Raise the temperature to 700℃ at a rate of 2-5℃ / min, keep warm for 0.5-1h, and remove wax for sintering; 3) Raise the temperature to 1300℃ at a rate of 2-5℃ / min, keep warm for 1-2h, and sinter in vacuum.
[0013] The second sintering, before sintering, first put a graphite ring on the outer circle of the roller ring, the gap between the outer circle of the roller ring and the graphite ring is 4-6mm, then fill the gap between the outer circle of the roller ring and the inner hole of the graphite ring, and the inner hole of the roller ring with alumina powder and press it, and then pressurize and sinter to 1360-1380℃, as follows: 1) Raise the temperature to 600℃ at a rate of 2-5℃ / min, keep warm for 1-2h, and sinter in vacuum; 2) Raise the temperature to 1360℃ at a rate of 2-5℃ / min, keep warm for 0.5-1h, and apply pressure to 3-5Mpa.
[0014] During the first sintering, the vacuum degree was 50pa, the heating rate was 3℃ / min, and the temperature was kept at 1300℃ for 1 hour. Then the sintering furnace started the fast cooling mode, cooled to 80℃, opened the furnace door, and took out the product.
[0015] During the second sintering, the alloy was sintered at 1360°C in an argon atmosphere for 1 h.
[0016] Example 2.
[0017] In this embodiment, the blank size selected is φ380*φ260*120, and the designed size after sintering is φ385*φ255*125. The method of secondary sintering and landfilling alumina in Example 1 is adopted, and the actual size obtained is φ386*φ256*123, which effectively prevents the roller ring from falling and deforming during sintering.
[0018] Although embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and concepts of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A method for controlling the sintering deformation of a high-cobalt cemented carbide roller ring, characterized in that: The blank is sintered in two steps; The first sintering, wax removal and vacuum sintering to 1300℃ to complete the shrinkage of the blank; The second sintering, before sintering, first put a graphite ring on the outer circle of the roller ring, the gap between the outer circle of the roller ring and the graphite ring is 4 to 6 mm, then fill the gap between the outer circle of the roller ring and the inner hole of the graphite ring, and the inner hole of the roller ring with alumina powder and press it, and then pressurize and sinter to 1360 to 1380 ° C.
2. The method for controlling the sintering deformation of a high-cobalt cemented carbide roller ring according to claim 1 is characterized in that: During the first sintering, the specific process is as follows: 1) Raise the temperature to 380℃ at a rate of 2-5℃ / min, keep warm for 1-2h, and remove wax for sintering; 2) Raise the temperature to 700℃ at a rate of 2-5℃ / min, keep warm for 0.5-1h, and remove wax and sinter; 3) Raise the temperature to 1300℃ at a rate of 2-5℃ / min, keep warm for 1-2h, and sinter in vacuum.
3. The method for controlling the sintering deformation of a high-cobalt cemented carbide roller ring according to claim 1 or 2, characterized in that: During the second sintering, the specific process is as follows: 1) Raise the temperature to 600℃ at a rate of 2-5℃ / min, keep warm for 1-2h, and sinter in vacuum; 2) Raise the temperature to 1360℃ at a rate of 2-5℃ / min, keep warm for 0.5-1h, and apply pressure to 3-5Mpa.
4. The method for controlling the sintering deformation of a high-cobalt cemented carbide roller ring according to claim 2, characterized in that: During the first sintering, the vacuum degree was 50pa and the heating rate was 3℃ / min. After the sintering was completed, the sintering furnace started the fast cooling mode, cooled to 80℃, opened the furnace door, and took out the product.
5. The method for controlling the sintering deformation of a high-cobalt cemented carbide roller ring according to claim 3 is characterized in that: During the second sintering, the alloy was sintered at 1360°C in an argon atmosphere for 1 h.
6. The method for controlling the sintering deformation of a high-cobalt cemented carbide roller ring according to claim 1, characterized in that: The gap between the outer circle of the roller ring and the graphite ring is 5mm.