Views: 1 Author: Site Editor Publish Time: 2022-11-15 Origin: Site
The reason why cemented carbide (cemented carbide) can be widely used in aerospace, aviation, navigation, consumer electronics, national defense, military, medical, automotive and other fields is that it has extremely excellent physical and chemical properties, namely, high proportion, high hardness, high strength, good thermal hardness, wear resistance, heat resistance, acid and alkali resistance, etc. What is the thermal hardness of cemented carbide?
Thermal hardness refers to the ability of cemented carbide materials to maintain high hardness at high temperatures, and its value shall be tested with a hardness standard block or a hardness tester at high temperatures. The hardness of common cemented carbide is 86 ～ 93HRA (equivalent to 69 ～ 81HRC), while the hardness of the alloy remains unchanged at 500 ℃, and it still has a high hardness at 1000 ℃, about 60HRC.
Cemented carbides are often used to manufacture long-life hot working dies, such as hot forging dies, hot extrusion dies, die-casting dies, hot upsetting dies, hot punching dies, and hot flat forging dies, due to their high thermal hardness, fatigue resistance, good wear resistance and oxidation resistance. For example, the hot upsetting extruding die for the air valve tappet made of 3Cr2W8V steel has a hardness of about 50HRC after heat treatment, and has been used for 5000 times. After that, some parts of the die have been replaced with YG20 cemented carbide inserts, and the use of the die has increased to 150000 times. The service life of the hot trimming die made of YG20 cemented carbide insert is increased to more than 100000 pieces.
Extended data: The hot and hard ones cannot be confused with the red and hard ones. Red hardness, also known as redness, refers to the ability of a material to maintain its hardness after being kept at a certain temperature for a certain period of time, and is tested at room temperature. The red hardness of the tool is generally measured by heating the tool to above 600 ℃ within a certain time, and then cooling it to room temperature. The tool can still maintain high hardness at 600 ℃, and its toughness, wear resistance and heat resistance are good, while its red hardness is good.