DL Steel Ring internal treatment quality comes from German Ipson Vacuum Quencher which enjoys following salient advantages:

1. This device has function of cleaning, carbon-azote pervasion and quenching, it is fully automatic controlled by computer, with an intelligence pre-alerting system monitoring the whole process.

2. The carbon-azote pervasion time, each section and media's temperature, carbon concentration and thickness of carbon layer are strictly and precisely controlled and adjusted by the computer.

3. Based on the above, DL Steel Ring surface hardness always remain in KRA81.5-83.5, difference with 1.5, pervasion layer remains in 0.4 to 0.6, surface carbon exceed 0.8%.