Surface modification apparatus for alloy steel component, surface modification method for alloy steel component, and method for manufacturing alloy steel component

Abstract

Provided are a surface modification apparatus for an alloy steel component, a surface modification method for an alloy steel component, and a method for manufacturing an alloy steel component, which can provide a deep and homogeneous hard layer for a steel component with a wide shape or a large amount of such steel components. A surface modification apparatus 100 includes a process furnace 101 , and the process furnace 101 performs a surface modification process on an alloy steel component 90 including an alloy steel material to which at least one kind of nitride formation element such as chromium, molybdenum, or aluminum is added. The surface modification apparatus 100 forms a compound layer on a surface of the alloy steel component 90 by exposing the alloy steel component 90 for at least 180 minutes to an atmosphere in the process furnace 101 maintained to have an ammonia gas concentration of 80% or more and a temperature of 620° C.

1 . A surface modification apparatus for an alloy steel component, which performs surface modification on an alloy steel component including an alloy steel material containing a nitride formation element, the apparatus comprising
 a surface modification processing unit for modifying a surface of the alloy steel component by exposing the alloy steel component for at least 180 minutes to an atmosphere with an ammonia gas concentration of 80% or more and a temperature of 610° C. or more and 630° C. or less.   
     
     
         2 . The surface modification apparatus for an alloy steel component according to  claim 1 , wherein the temperature is set to 620° C. by the surface modification processing unit. 
     
     
         3 . The surface modification apparatus for an alloy steel component according to  claim 1 , wherein the alloy steel component includes at least one of a corner portion with an acute shape and a hole portion with a diameter of 8 mm or less. 
     
     
         4 . A surface modification method for an alloy steel component including an alloy steel material containing a nitride formation element, the method comprising
 a surface modification processing step of modifying a surface of an alloy steel component by exposing the alloy steel component for at least 180 minutes to an atmosphere with an ammonia gas concentration of 80% or more and a temperature of 610° C. or more and 630° C. or less.   
     
     
         5 . The surface modification method for an alloy steel component according to  claim 4 , wherein the temperature is set to 620° C. in the surface modification processing step. 
     
     
         6 . The surface modification method for an alloy steel component according to  claim 4 , wherein the alloy steel component includes at least one of a corner portion with an acute shape and a hole portion with a diameter of 8 mm or less. 
     
     
         7 . A method for manufacturing an alloy steel component including an alloy steel material containing a nitride formation element, the method comprising
 a surface modification processing step of modifying a surface of an alloy steel component by exposing the alloy steel component for at least 180 minutes to the atmosphere with an ammonia gas concentration of 80% or more and a temperature of 610° C. or more and 630° C. or less.   
     
     
         8 . The surface modification apparatus for an alloy steel component according to  claim 2 , wherein the alloy steel component includes at least one of a corner portion with an acute shape and a hole portion with a diameter of 8 mm or less. 
     
     
         9 . The surface modification method for an alloy steel component according to  claim 5 , wherein the alloy steel component includes at least one of a corner portion with an acute shape and a hole portion with a diameter of 8 mm or less.