HEAT TREATMENT

Heat treatment is a term used in the industry to describe a process whereby the physical properties of a metal may be charged by subjecting it to heat.

Here the job is cooling by air, water and oil. To hold the job various type of tools is used. Metals can be of two types: alloy steel/tool steel and mild steel.

Figure: Heat Treatment Department/Heat Treatment 4&5 Furnace

Alloy steel :

Alloy steels are those which contain, in addition to carbon and iron, some alloying elements, such as chromium, vanadium, nickel, molybdenum or tungsten, which give them some particular characteristics not possessed by ordinary steel

Mild steel

Mild steel at first carburizing and then it is hardened in oil, water or air .

Preparation for carburizing:

1) Charcoal – 58%

2) Barium carbonate – 15%

3) Sodium – 0.2%

4) Molasses – As required

5) Stone Coal – 25%

Different types of machine and furnace :

1. Semi-Muffle Gas Fire furnace

2. Salt bath Muffle Gas Fire furnace

3. Rock Well Hardness Tester

4. Water bath for quenching

5. Electrical Super Heating Furnace

6. Electrical Circulating Tempering Furnace

7. Oil- Bath For Quenching

8. Grinding wheel machine

1)Semi-Muffle Gas Fire furnace : Various type of gas and Electrical furnace used for heat treatment.

# Procedure : The temperature of carburizing is 950 ⁰C to 1000 ⁰C. Here carbon push 1-2 mm. The temperature of hardening 750 ⁰C to 800 ⁰C, The temperature of alloy steel is 850 ⁰C to 1150 ⁰C, The temperature of tempering is 150 ⁰C to 550 ⁰C and The temperature of annealing is 600 ⁰C to 650 ⁰C.

2)Electrical Super Heating Furnace : It is used to hardening.

3)Salt bath Muffle Gas Fire furnace : It is used for carburizing and hardening.

4)Oil- Bath For Quenching : The name of the oil is silt volute which is used in oil Bath.

# operation : It is used to quenching the job.

5)Rock Well Hardness Tester : It is used to measure the hardness of metal.

6)Electrical Circulating Tempering Furnace : It is used to tempering. The temperature of tempering is 150 ⁰C to 550 ⁰C. When hardness is more than need then the hardness is minimize by this machine.

7)Grinding wheel machine : It is used to spark test of material.

Comments

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