SCHEDULE II(ss. 2 and 21)Heat Treatment
Annealing
1 (1) Annealing shall be carried out by heating the material in a closed furnace to 620°C-650°C holding at this temperature for a period of time not less than 30 or more than 60 minutes for each 25 mm thickness of the material and then allowing the furnace and material to cool down slowly together; cooling of the material may be effected by removing it from the furnace and covering the material with some medium that ensures a slow rate of cooling.
(2) Annealing shall not be carried out in an open fire.
(3) Annealing shall only be used for Class A gear.
Normalizing
2 (1) Normalizing shall be carried out by heating the material to 900°C in a closed furnace, holding it at this temperature for a period of time not less than 30 or more than 60 minutes for each 25 mm thickness of material, removing it from the furnace and allowing the material to cool in still air at room temperature.
(2) Normalizing shall not be carried out in an open fire.
(3) Normalizing shall only be used for Class B gear.
3 (1) The heat treatment for alloy steel gear shall be that heat treatment as specified by the manufacturer of such gear.
(2) Alloy steel gear that requires heat treatment shall be returned to the manufacturer or to an establishment qualified to carry out such treatment and in no case shall indiscriminate heat treatment be attempted.
- SOR/79-784, ss. 18, 19
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