Meetyou company has been making YG series cemented carbide molds since 2003. Through practical verification and repeated test comparison, the structure and processing method of cemented carbide parts have been continuously improved. Stable use in production has created considerable economic benefits for the company.
1. Cemented carbide die structure
Due to the particularity of cemented carbide, its price remains high. In order to reduce the die cost, it is often used in the most critical part in the manufacturing process – the die structure with cemented carbide parts. The die inlaid with ring and block cemented carbide sleeve has simple structure and simple processing method. At present, it has been widely used in molds for forming, drawing and other processes.
The outer circumferential surface of cemented carbide is used as the working surface (see Fig. 1 and Fig. 3); The inner circumferential surface of cemented carbide is used as the working surface.
2. Cemented carbide die making procedures
The assembly and fixing of insert sleeve the insert sleeve of cemented carbide die is traditionally welded with molten copper and hot installed. According to the steel materials matched with cemented carbide, the reasonable interference is selected to roughen the assembly joint surface. Cemented carbide is a powder metallurgy material with high compressive strength and low tensile strength.
(1) Inlaid cemented carbide jacket is mostly welded with copper. Dehydrated borax is used. The inner hole of cemented carbide jacket is roughened, and the peripheral joint surface of inner core and outer circle of steel material is processed into polygon. The cemented carbide inner hole and steel inner core adopt the structure of inner junction polygon, so that after they are matched, they can not only ensure the positioning accuracy, but also make the molten copper flow smoothly into the gap of polygon and be firmly integrated.
If an interference fit is used, use a small interference fit to prevent brace cracking.
Note: after copper welding, it shall be kept warm in time, put into the oven or embedded with materials with good thermal insulation, slowly reduce it to room temperature, and remove the internal stress by aging.
(2) Insert the cemented carbide inner sleeve. In order to prevent loose fit during use, use interference fit, heat the steel outer sleeve and press it into the cemented carbide inner sleeve. However, the proper amount of interference shall be strictly controlled to prevent excessive support cracking of the steel jacket.
Note: heat preservation shall be carried out in time after hot assembly as after welding, and materials with good heat preservation shall be put into the oven or embedded, slowly reduced to room temperature, and the internal stress shall be removed by aging.
(3) The method of physical cold extrusion fixation is adopted. In the manufacturing process, the steel material and cemented carbide sleeve have small interference and are extruded and fixed with fine threads, and the threaded connection is coated with locking anaerobic glue.
the assembly methods of traditional structures are with simple structure and low manufacturing cost. The disadvantage is that whether it is hot charging or copper welding, it will more or less adversely change the structure of frame material and YG8 material; The insert sleeve is easy to crack and fall off during use.
more and more assembly methods have been adopted in recent years to avoid the impact of high temperature on the die material and ensure the stability of the die in the use process. The disadvantage is that the manufacturing process is complex and the processing technology requirements are high.