Induction Brazing carbide to steel shaft

Objective Brazing a cone shaped carbide to a stainless steel shaft for a digger
Material Cone shaped carbide 1.12” (28.4mm) dia, 1.5”(38.1mm) tall, stainless steel shaft 1.12” (28.4mm) dia and various length, black brazing flux and braze shims
Temperature 1500 ºF (815 ºC)
Frequency 57 kHz
Equipment • Power of 25kW induction heating system, equipped with a remote workhead containing two 1.0μF capacitors for a total of 0.5μF
• An induction heating coil designed and developed specifically for this application.
Process A three turn helical coil is used to braze the carbide to the shaft. The steel shaft is fluxed and the braze shim placed on top. The carbide tip is fluxed and placed on top of the shim, lining up the countersunk hole in the carbide. The hole is not fluxed because the flux outgases and causes the carbide to build up pressure and attempt to repel
from the shaft. Power is applied for 85 seconds for the braze shim to flow and make a good joint.
Narrative
• This customer is new to UIHM and discovered UIHM through a web search. UIHM’s customer has a customer who is unhappy with the braze quality of their digger so our customer is looking for a better quality brazing process.
UIHM’s customer is very happy with the sample brazed diggers and the help he received from the UIHM lab in
developing his brazing process.
Results/Benefits Induction heating provides:
• Rapid localized heating only where needed
• Creates clean, controllable joints
• Hands-free heating that involves no operator skill for manufacturing
• Even distribution of heating

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