Influence of Scanning Conditions on Properties of Electron Beam Hardening 891333
There are many methods for case hardening such as conventional
induction hardening and newly developed electron beam
Electron beam hardening has been adopted in Isuzu and the
reliability of engines has been improved.
The beam power of the electron beam hardening equipment used was
6 kW. Various conditions of electron beam were scanned across
specimens (SCM435H) in order to investigate the influence on
hardening properties. As a result, relation between case depth and
beam current and relation between case depth and beam scanning time
were confirmed. And when the depth exceeded 1 mm, there were cracks
in surface melted area.
Electron beam hardening was applied to tappets according to the
above fundamental experiments, and uniformly hardened layers were
obtained. Durability of engines with electron beam hardened tappets
was improved twice as much as those with non-hardened tappets.