Method for manufacturing a wear plate of a disc chipper and wear plate of a disc chipper

Abstract

The present invention concerns a method for manufacturing wear plates of a disc chipper. The wear plate is provided with a plated surface by sintering in an oven at a temperature of 900-1000° C. Selective portions of the wear plate are strengthened by quenching and hardening utilizing the temperature achieved in connection with sintering.

1 . Method for producing a wear plate used for clamping knifes in disc chippers, the wear plate having a tip portion in contact with a clamped knife, in which method a prefabricated wear plate is furnished with a wear surface by sintering a plating on said surface in an oven in a temperature of 900 to 1000° C., wherein, when the temperature of the blank is after the sintering still in the austenitic area (over 840-870° C.), local quenching and hardening of the tip portion by means of a forced cooling is performed.  
     
     
         2 . Method for producing a wear plate used for clamping knifes in disc chippers, the wear plate having a tip portion and a support portion in contact with a clamped knife, in which method a prefabricated wear plate is furnished with a wear surface by sintering a plating on said surface in an oven in a temperature of 900 to 1000° C., wherein, when the temperature of the blank is after the sintering still in the austenitic area (over 840-870° C.), local quenching and hardening of the tip portion and the support portion by means of a forced cooling is performed.  
     
     
         3 . A method in accordance with  claim 1 , wherein the forced cooling is performed by means of a selective jet of cooling medium.  
     
     
         4 . A wear plate for clamping knifes in disc chippers, the wear plate consisting of a steel blank having a plated wear surface of wear resistant material sintered on said surface, and a tip portion in contact with a clamped knife, wherein the tip portion is quenched and hardened by means of forced cooling when the blank still is in austenitic area, in a temperature over 840 to 870° C., after the sintering in an oven in a temperature of 900 to 1000° C.  
     
     
         5 . A wear plate for clamping knifes in disc chippers, the wear plate consisting of a steel blank having a plated wear surface of wear resistant material sintered on said surface, a tip portion and a support portion in contact with a clamped knife, wherein the tip portion and the support portion are quenched and hardened by means of forced cooling when the blank still is in austenitic area, in a temperature over 840 to 870° C., after the sintering in an oven in a temperature of 900 to 1000° C.  
     
     
         6 . A wear plate ( 4 ) of a disc chipper according to  claim 4 , wherein a layer decarburized in the quenching and hardening has been removed by machining.  
     
     
         7 . A wear plate of a disc chipper according to  claim 4  wherein the blank of the wear plate consists of boric steel alloy comprising approximately C=0.20 to 0.25%, Si=0.2%, Mn=1.2%, Ni=0.04%, Cr=0.27%, Al=0.03%, B=0.002% and Fe about 98%.  
     
     
         8 . A wear plate ( 4 ) of a disc chipper according to  claim 5 , wherein a layer decarburized in the quenching and hardening has been removed by machining.  
     
     
         9 . A wear plate of a disc chipper according to  claim 5  wherein the blank of the wear plate consists of boric steel alloy comprising approximately C=0.20 to 0.25%, Si=0.2%, Mn=1.2%, Ni=0.04%, Cr=0.27%, Al=0.03%, B=0.002% and Fe about 98%.  
     
     
         10 . A wear plate of a disc chipper according to  claim 6  wherein the blank of the wear plate consists of boric steel alloy comprising approximately C=0.20 to 0.25%, Si=0.2%, Mn=1.2%, Ni=0.04%, Cr=0.27%, Al=0.03%, B=0.002% and Fe about 98%.  
     
     
         11 . A wear plate of a disc chipper according to  claim 8  wherein the blank of the wear plate consists of boric steel alloy comprising approximately C=0.20 to 0.25%, Si=0.2%, Mn=1.2%, Ni=0.04%, Cr=0.27%, Al=0.03%, B=0.002% and Fe about 98%.