Steel Part and Method for Manufacturing the Same

Abstract

A plurality of layers are laminated on at least part of the member under treatment made of steel, the plurality of layers having carbon concentrations higher than that of the member under treatment and 1.0 wt. % or less, the carbon concentration of an outermost layer of the plurality of layers being the highest. A method for manufacturing a steel part, including spraying powder containing carbon on at least part of an member under treatment made of steel so as to form a first layer having a carbon concentration higher than that of the member under treatment and spraying powder containing carbon on at least part of the first layer so as to form a second layer having a carbon concentration higher than that of the first layer. Carbon concentrations of a plurality of layers including the first layer and the second layer are 1.0 wt. % or less.

1 . A steel part having a member under treatment made of steel, a plurality of layers being laminated on at least part of the member under treatment, the plurality of layers having carbon concentrations higher than that of the member under treatment and 1.0 wt. % or less, the carbon concentration of an outermost layer of the plurality of layers being the highest. 
     
     
         2 . The steel part according to  claim 1 ,
 wherein the plurality of layers are three layers or more.   
     
     
         3 . The steel part according to  claim 1 ,
 wherein the member under treatment has an area in which the plurality of layers are laminated and an area in which the plurality of layers are not laminated.   
     
     
         4 . The steel part according to  claim 1 ,
 wherein the plurality of layers includes a first layer and a second layer laminated successively on the member under treatment, the first layer having an area in which the second layer is laminated and an area in which the second layer is not laminated.   
     
     
         5 . A method for manufacturing a steel part, comprising:
 spraying powder containing carbon on at least part of an member under treatment made of steel so as to form a first layer having a carbon concentration higher than that of the member under treatment; and   spraying powder containing carbon on at least part of the first layer so as to form a second layer having a carbon concentration higher than that of the first layer,   wherein carbon concentrations of a plurality of layers including the first layer and the second layer are 1.0 wt. % or less.   
     
     
         6 . The method for manufacturing the steel part according to  claim 5 , comprising:
 spraying powder containing carbon on at least part of the second layer so as to form a third layer having a carbon concentration higher than that of the second layer.   
     
     
         7 . The method for manufacturing the steel part according to  claim 5 ,
 wherein the plurality of layers are formed while the member under treatment is heated.