Feasibility study of implementing an industrial robot for induction

5.2.5 Induction hardening 
Induction hardening is a case hardening process which is used to increase wear 
the resistance, surface hardness and fatigue life via a process of hardening only 
the surface layer of a component and keeping the core structure unaffected. The 
process is used in increasing the mechanical properties of ferrous materials at a 
specific required area /6/ 
Induction hardening has a number of benefits in that it is very good for 
components that are subjected to heavy loads. Induction hardening provides a 
high surface hardening and therefore gives the component the ability to handle 
extremely heavy loads without fracturing. Induction hardening provides a tough 
outer layer thereby softening the core which makes it capable to increase the 
fatigue strength of the component and makes it suitable for parts with torsional 
load force. Induction hardening is also good for surfaces with heavy sudden load 
or impact surface forces. The process provides a high surface hardness and deep 
case makes the material capable to carry heavy loads. /6/ 
Induction hardening is applied to components such as gears, shafts, axles, cam 
lobes, stampings and spindles. The process is carried out to harden a specific area 

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of such parts. The process can be carried out with materials such as carbon steels, 
alloy steels, stainless steels, cast iron, gray iron, ductile iron and malleable iron. 
The induction section at Bodycote Vaasa is employs two induction hardening 
machines as shown in Figure 13. The big one is used for hardening large and 
heavy components while the small induction hardening machine is used for 
smaller components that are of light weight. 
Figure 13. A picture of the big and small induction hardening machine at 
Bodycote Vaasa. 
The study is based on the small induction hardening machine. The small induction 
hardening machine is used for smaller components within the range of 80g to 
1500g in weight. There can be thousands pieces of a particular component that 
need to be hardened by the machine and they are hardened individually one after 
another but with the same heating and handling time. Figures 14 and 15 show the 
side and front view of the small induction machine. A chuck and suitable holding 

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device are provided for holding the work piece securely during the hardening 
process. 
Figure 14. The front view of the small induction machine. 
Figure 15. The side view of the small induction machine