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AssigneeECM Technologies
InventorsPhilippe Lapierre, Jerome Lardinois, Yves Giraud, Alfred Rallo
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A method for the low-pressure carbonitriding of steel parts, in particular parts used in the manufacture of automobiles comprises a heating step that includes a simple heating phase (M) followed by an initial nitridation phase (Ni) from a temperature between 700° C. to 750° C. to a temperature between 860° C. and 1000° C. and carried out using a reduced temperature gradient relative to the simple heating phase. Additionally, alternate cementing (C1-Cn) and nitridation (N1-Nn) steps are performed at constant temperature, wherein the final nitridation step is accompanied with a decrease in temperature immediately before quenching (T).
A low-pressure carbonitriding method of steel parts comprising alternating cementation and nitriding steps, preceded by a step of increasing temperature comprising a continuously increasing temperature phase followed by an initial nitriding phase during which the increase of temperature is continued, and followed by a quenching step, wherein the initial nitriding phase is carried out from a first temperature in the range from 700° C. to 750° C. increasing up to a second temperature in the range from 860° C. to 1,000° C.
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