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Abstract

Necks of a spindle of the heavy lathe from the alloyed steel 35HN3MFA 6500 mm long and crests of carriage wheels diameter from qualitative carbon steel are processed by surface plasma tempering. It has been proved possibilityto increase reliability of
workof large-size and massive parts of different function by way of plasma hardening of their surfaces. It is shown that on hardening depth formation of several structural zones of different microhardness is observed, which claims of formation of gradient laminated structure clearly. It is confirmed that at the superfast speed of heating that takes place at surface plasma tempering, phase and structural transformations are displaced in area of high temperatures, strongly changing kinetics of emergence and growth of germs of a new phase (austenite). At this stage fine-grained austenite is formed which turns into the high-disperse martensitic structure unattainable at traditional ways of heat treatment forms.