Carburization treatment method and carburization treatment apparatus

Abstract

The invention provides a carburization treatment method in which a carburization treatment is conducted simultaneously with an operation of supplying a hydrocarbon gas and an oxidative gas into a furnace kept under a reduced pressure. Preferably, the internal pressure within the furnace is kept at 0.1 to 101 kPa, the hydrocarbon gas is one, two or more than two kinds of gases selected from the group consisting of C 3 H 8 , C 3 H 6 , C 4 H 10 , C 2 H 2 , C 2 H 4 , C 2 H 6 and CH 4 , while the oxidative gas is an air, an O 2 gas, or CO 2 gas.

1 . A carburization treatment method comprising performing the carburization treatment while supplying a hydrocarbon gas and an oxidative gas into a furnace kept at a reduced pressure.  
     
     
         2 . A carburization treatment method according to  claim 1 , wherein the carburization treatment is conducted while supplying a hydrocarbon gas and an oxidative gas into the furnace, and an inert gas is further supplied during the carburization treatment.  
     
     
         3 . A carburization treatment method according to  claim 1 , wherein an internal pressure of the furnace is 0.1 to 101 kPa.  
     
     
         4 . A carburization treatment method according to  claim 1 , wherein the hydrocarbon gas is at least one selected from the group consisting of C 3 H 8 , C 3 H 6 , C 4 H 10 , C 2 H 2 , C 2 H 4 , C 2 H 6 , and CH 4 .  
     
     
         5 . A carburization treatment method according to  claim 1 , wherein the oxidative gas is air, O 2  gas or CO 2  gas.  
     
     
         6 . A carburization treatment method according to  claim 1 , wherein a carbon potential of an atmosphere within the furnace is controlled by controlling the amount of at least one of the hydrocarbon gas and the oxidative gas that are supplied.  
     
     
         7 . A carburization treatment method according to  claim 6 , wherein the amount of at least one of the hydrocarbon gas and the oxidative gas is controlled based on at least one of the following measurements: measurement of CO gas partial pressure, measurement of CO gas concentration, measurement of CO 2  gas partial pressure, measurement of CO2 gas concentration, measurement of O2 gas partial pressure, measurement of O2 gas concentration, measurement of H2 gas partial pressure, measurement of H2 gas concentration, measurement of CH4 gas partial pressure, measurement of CH4 gas concentration, measurement of H2O partial pressure, measurement of H2O concentration, and measurement of dew point, all within the furnace.  
     
     
         8 - 11 . (canceled)