Round size:

diameter:20-350mm   length:2500-4000mm  or customer requested.

Factory state: soft annealing to HB 185.    skd61 mould steel flat

Comparable Standards:                                                                                                       

 Chemical Analysis (%):                                                                                                         

Heat treatment                                                                                                       

Isothermal annealing:

-   Heat to 880°C, hold at temperature for 1/2 h to 1 h;

-   Furnace cooling to 780°Cand hold at temperature for at least 5 hours;

-   Cool by 10°C/h to 750°C;

-   Cooling in air.

Maximum hardness: 230 HB

Stress relieving:

To be carried out after maching and before the final heat treatment.

-   Heat to 650÷700°C, hold for 4÷6 hours;

-   Furnace cooling to 300÷350°C;

-   Cooling in air.

Hardening:

-   Initial preheating to 350÷450°C;

-   Second preheating to 750÷850°C;

-   Heat to hardening temperature in the range 1000÷1050°Cand hold at temperature;

-   Cooling in air.

Quenched hardness: 52÷56 HRC

Tempering:

In the range 550÷630°Cfor at least 3 hours according to hardness requirements and conditions of use.

Tempering must be repeated a second time at a temperature to or 20°Clower than the previous.

    Before tempering, preheat the parts to 200÷300°C.