High Speed Steel

Typical Analysis :


Forging
M2 steel component is slowly and uniformly pre-heated to 850-900°C and then the heat is increased till forging temperature of 1050-1150°C. If during the forging the temperature of the material drops below 880-900°C, Re heating is necessary if temperature of the M2 material gets below 880-900°C . After forging,slowly the M2 component should be cooled down.

Annealing
Annealing should be done after hot working and before the component is re hardened. M2 high speed steel is heated to 850°C at a rate of no more than 220°C per hour. Always hold at temperature for one hour / 25mm of thickness (with minimum two hours ). Then slowly it is cooled in the furnace. Annealed hardness>= 248 Brinell

Stress Relieving
Stress Relieving is done in order to minimize the distortion< if the tools made from this steel are heavily machined or are ground.The component is heated to 675-725°C ,soaked well (2hours approx.)and cooled in the air. Then the finishing of the tool is done.

Hardening
M2 steel is preheated in 2 steps- firstly at 450-500°C then 850-900°C. Then it is heated to the final hardening temperature ,i.e.,1200-1250°C . NOTE: Donot allow the component to stand too long at hardening temperature. Quenching is done in warm oil or brine. If quenching done in brine lets the tools to equalize, then quenching in air is done. If the quenching is done in oil, then remove the M2 component from the oil at 500°C and then cool in air. Vacuum hardening can also be done.

Tempering
The component needs to be tempered immediately after quenching.Uniform heating to the selected tempering temperature is done and it must be held for at least two hours (one hour per 25mm of total thickness). Double tempering is recommended and for the tools that are cut by wire EDM,we recommend triple tempering .

Physical Properties


Final Grinding : It needs to be done in good condition using a suitable dressing tool.Wet grinding is preferable.

Heat Treatment : This procedure will vary according to the shape and size of M2 tool component.Rate of heating,rate of cooling and soaking time depends on M2 shape and size.Other factors like type of furnace,medium for quenching etc also matter.

Forging : Pre heat the M35 high speed steel slowly and uniformly to 450-500°C and equalise. Then increase more quickly to the forging temperature of 950-1100°C and equalise prior to forging. Do not allow the forging temperature to drop below 950°C, if this occurs re heating will be necessary. Always cool the steel very slowly after forging.

Annealing : M35 is supplied in the annealed and machineable condition. Re annealing will only be necessary if the steel has been hot worked, forged, or hardened by the toolmaker. Heat the M35 high speed steel to 850°C at a rate of no more than 220°C per hour. Always hold at temperature for one hour per 25mm of thickness (with two hours being minimum). Furnace cool slowly. The M35 annealed hardness achieved should be 260 Brinell or lower.

Stress Relieving : If tools produced from M35 high speed steel are heavily machined or ground it is recommended to stress relieve after machining and prior to hardening to minimise the possibility of distortion. To stress relieve heat the component to 600-700°C and soak well (approx 2 hours) Cool slowly in the furnace. The tools can be finish machined before heat treatment.

Hardening : For best results harden in a vacuum or controlled furnace, or in a properly rectified salt bath. Pre heat thoroughly in two steps to 450-500°C, then to 820-870°C, transfer to the high temperature salt bath or furnace. The exact hardening temperature to use for M35 will depend on the type of work being treated, but in general components should be hardened from the range of 1050-1250°C.

Tempering : M35 high speed steel components can be tempered between 510-620°C. Triple tempering is recommended with a minimum of two hours at temperature per cycle. The component should be cooled in still air to room temperature between tempering treatments.


Heat Treatment : Heat treatment temperatures, including rate of heating, cooling and soaking times will vary due to factors such as the shape and size of each M35 steel component. Other considerations during the heat treatment process include the type of furnace, quenching medium and work piece transfer facilities. Please consult your heat treatment provider for full guidance on heat treatment of high speed steels.

Final Grinding : Select the correct grade of wheel in consultation with the grinding wheel supplier. Ensure the grinding wheel is in good condition by means of a suitable dressing tool. Wet grinding is a preferable option using a copious supply of coolant. If dry grinding is resorted to then use a very soft wheel.