Method for reduction of time in a gas carburizing process and cooling apparatus utilizing a high speed quenching oil flow rate

摘要

The present invention provides a process for reduction of time in gas-carburizing process and cooling apparatus to perform carburization by step heating of a part during carburizing heating from 800° C., 850° C., 900° C. onwards to a carburization temperature of 930° C. with the part being held at each mentioned temperature for 10 minutes by adding LPG or propane along with methanol in the furnace for activation/diffusion, the holding time is thereby reduced for carburization, thereafter the carburized parts are quenched in the invented apparatus to discharge high severity of quenching. A quenching oil flow rate of about 1.6 meters per second is critical to the process.

主权项

1. A method for reduction of time in gas-carburizing, process utilizing step heating comprising the steps of:
placing a part into an atmospheric carburizing furnace; said carburizing furnace comprising;
a quenching chamber;a plurality of quench oil circulation pipes;each of said plurality of quench oil circulation pipes having an input end and an exit end;an agitating motor connected to said each of said input end; wherein quenching oil is directed to flow through therein at a selected flow rate anda perforated grid disposed on each of said exit end for selectively increasing said selected flow rate wherein said quenching oil is directed through said quenching chamber and recirculated; heating said part to a first selected temperature; holding said first temperature for a first selected time interval while adding a hydro-carbon gas along with methanol into said furnace; heating said part to a second selected temperature; holding said second temperature for a second selected time interval while adding a hydro-carbon gas into said furnace; heating said part to a third selected temperature; holding said third temperature for a third selected time interval while adding a hydro-carbon gas into said furnace; heating said part to a final selected temperature; holding said final temperature for a final selected time interval while adding a hydro-carbon gas into said furnace; andwherein said first selected temperature is 800° C., said second selected temperature is 850° C., said third selected temperature is 900° C. and said selected final temperature is 930° C.