Method of solid state welding and welded parts

A method of solid state welding metal parts together having opposed generally coplanar parallel surfaces, said method comprising:

• locating a high frequency induction heater between said opposed surfaces of said metal parts;
• induction heating about the first 0.050 inches or less of said opposed surfaces of said metal parts with said high frequency induction heater at a frequency of 8 kilohertz or greater while simultaneously flooding said opposed surfaces of said metal parts with a non-oxidizing gas;
• quickly removing said high frequency induction heater from between said opposed surfaces of said metal parts and continuously moving at least one of said parts relative to the other of said parts generally parallel to said opposed co-planar parallel surfaces;
• and
• quickly bringing said opposed surfaces of said parts together while continuing to move said one at least one of said parts to friction weld said opposed surfaces of said metal parts together, wherein at least about 90% of the energy of welding is supplied by said high frequency induction heater and the balance of welding energy is supplied by conventional kinetic energy.

A metal part having opposed planar surfaces friction welded together including a generally planar flash extending radially from the intersection of said opposed planar friction welded surfaces having a volume corresponding to a combined loss of length of less than 0.2 axial inches per inch of wall thickness formed by the following process:

• heating said opposed planar parallel surfaces with a high frequency induction heater to the hot working temperature of said metal part in a non-oxidizing atmosphere;
• continuously moving one of said opposed planar surfaces relative to the other of said planar surfaces generally parallel to said opposed planar parallel surfaces;
• and
• quickly bringing said opposed surfaces together with said forging force to friction weld said opposed surfaces together and said metal part.

A method of solid state welding metal parts together having opposed generally co-planar parallel surfaces, said method comprising:

• quickly heating said opposed surfaces of said metal parts with an induction heater at a frequency of about 20 kilohertz or greater such that the induction heating is confined to about the first 0.050 inches or less of said opposed surfaces of said metal parts;
• continuously moving at least one of said metal parts relative to the other of said parts generally parallel to said opposed planar and parallel surfaces;
• and
• quickly bringing said opposed surfaces of said parts together while continuing to move at least one of said parts until the absorbed kinetic energy is approximately equal to 10% or less of the energy input prescribed by conventional friction welding to solid state weld said opposed surfaces of said metal parts together.

A method of solid state welding metal parts together having opposed generally coplanar parallel surfaces, said method comprising:

• locating a high frequency induction heater between said opposed surfaces of said metal parts;
• induction heating said opposed metal surfaces of said metal parts with said high frequency induction heater at a frequency of 8 kilohertz or greater in a non-oxidizing atmosphere;
• quickly moving said high frequency induction heater from between said opposed surfaces of said metal parts and continuously moving at least one of said metal parts relative to the other of said metal parts generally parallel to said opposed co-planar parallel surfaces;
• and
• quickly bringing said opposed surfaces of said metal parts together while continuing to move said at least one of said parts to friction weld said opposed surfaces of said metal parts wherein a combined loss of length of said metal parts resulting from flash is less than 0.2 axial inches per inch of wall thickness of said metal parts.