The hardness of the high-speed tool steel in the annealed state is not particularly high, and the hardness of some materials in the delivery state is even similar to that of medium carbon steel (about HB300). Therefore, there is no problem in turning, milling and planing in the annealed state, but after quenching The hardness of the high-speed steel is very high (generally the hardness is above HRC60). In the early days, due to the limitation of tool materials, it could only be processed by grinding. So what kind of tool is used to process quenched high-speed steel?

In recent years, more and more high-speed steels have been used to make rolls, molds and other parts. As cubic boron nitride (CBN) tools are used more and more widely, CBN tools are used to process high-hardness quenched high-speed steel. as follows

1. CBN tool processing hardness HRC67 quenched high speed steel case

Processing material: HRC 67 degree high-speed steel (imported powder high-speed steel material)

Processing sequence:

Processing difficulties:

a. Due to the high cutting temperature, the cutting edge of the currently used CBN tools often drops the tip when in use.

b. The tool life is too low. In the case of 600 rpm, fine turning is 0.02mm, the finish will quickly deteriorate, the frequency of tool changes is high, and the maximum tool life is 37 pieces. The cutting speed was changed to 1000 rpm, which showed better finish, but lower tool life

Tool plan:

1. Redesign of the tool structure: Due to the high hardness of high-speed steel processing, in view of the lack of rigidity of the non-standard groove tool used by the customer before, the tool often drops head after being heated, so it is changed to the standard groove knife blade structure;

2. Tool material: The tool material is BN-H05, which is more resistant to high temperature and cutting hardness. The customer uses it normally, and there is no unstable cutting size and roughness; the customer is very satisfied with the durability and cost of the tool .