HARDENING METHOD FOR A SOLID SOLUTION DEFORMABLE FOR LOW-TEMPERATURE PREPARATION OF PASSIVE ALLOY AND A PART Hardened in a SOLID SOLUTION USING THE METHOD

摘要

1. The method of formation of expanded austenite and / or expanded martensite by quenching a solid solution of a workpiece made of a passive alloy based on iron, nickel and / or cobalt, and also containing at least 10% chromium or an alloy based on iron, deformed at low temperatures containing at least 10.5% chromium, the method comprising the first step of dissolving at least nitrogen in the workpiece at a temperature T1 that is higher than the solubility temperature for carbide and / or nitride, and also below the melting point of the passive alloy and, at the same time, at a temperature T1, a nitrogen dissolution is performed to achieve a diffusion depth in the range from 50 μm to 5 mm, and the subsequent second step is the dissolution of nitrogen and / or carbon in the workpiece at a temperature T2 of at least 300 ° C and temperature T2 lower than the temperature at which carbides and / or nitrides are formed in the passive alloy, the method further comprising an intermediate step of cooling the workpiece after the dissolution step at a temperature T1 to a temperature which is lower than the temperature at which in the passive alloy form a carbide and / or nitridy.2. The method according to claim 1, characterized in that the dissolution at a temperature of T2 occurs immediately after cooling after dissolution at a temperature of T1.3. A method according to any one of claims 1 or 2, characterized in that the cooling step occurs in an inert gas, preferably an inert gas, not containing nitrogen. The method according to claim 3, characterized in that the inert gas in addition to constant impurities is argon. The method according to claim 1, characterized in that the nitrogen and carbon are dissolved at a temperature of T1.6. The method according to claim 1, characterized in that the passive