The GCr15 bearing steel ball is a bearing steel ball made of GCr15 steel. If you want to have a complete understanding of it and be able to use it correctly and reasonably, you need to master its relevant knowledge. Only in this way, in the use of GCr15 bearing steel ball, can we expect the desired effect and good economic benefits.
1. GCr15 bearing steel ball steel grades
GCr15 bearing steel ball steel grades have relevant regulations, the carbon content in the steel number is not marked out, and the chromium content is expressed in several thousandths. So, through GCr15, we can know that its chromium content is fifteenths of a thousandth.
2. Quality requirements of GCr15 bearing steel balls
GCr15 bearing steel ball in the smelting quality requirements are very strict, we must strictly control the sulfur, phosphorus and non-metallic inclusions in the content and distribution, so as not to affect the life of the bearing steel ball. On the other hand, it requires a pure and uniform structure and a low content of non-metallic impurities. In addition, the carbides in the steel should be evenly distributed.
3. GCr15 bearing steel ball heat treatment process
The heat treatment of GCr15 bearing steel balls is an annealing of steel rods and wires, or an oil quench of 830-840 degrees.
GCr15 bearing steel ball heat treatment process parameters
Ordinary annealing: 790-810 degrees heating, when the furnace is cooled to 650 degrees after the air cooling, the process parameter is HB170-207.
Isothermal annealing: 790-810 degrees heating and 710-720 degrees of isothermal, followed by air cooling, process parameters HB207-229.
Normalizing: 900-920 degrees heating, and then air cooling, process parameters for the HB270-390.
High temperature tempering: 650-700 degrees heating plus air cooling, process parameters HB229-285.
Quenching: 860 degrees heating, then oil quenching, process parameters for HRC62-66.
Low temperature tempering: 150-170 degrees tempering plus air cooling, process parameters HRC61-66.
4. GCr15 bearing steel ball annealing heat treatment process
GCr15 bearing steel ball annealing heat treatment method, there are two main, one is the first rapid induction heating temperature to 700 °C -720 °C, and then heat for 5 to 10 minutes, followed by air cooling. Another method is to first anneal the steel balls in an annealing furnace and then hold the temperature at 780°C for 40 minutes. After that, the furnace is air-cooled when the temperature drops to 700°C.