brazing cast steel

[hydmech]

I am trying to braze together a housing for a hydrulic pump where it is cracked it only gets about 30-50 psi of case pressure. What types of flux and fillers should i use to do this? It is completely cast steel. Should i use flux coated brazing rod or not?

 

[swall]

What is the alloy or spec of the casting?

 

[griffengm]

Hydmech,
One of the first problems you will encounter is having a casting saturated with oil. Makes it difficult to get a good bond since oil will continue to "cook" out of the metal for some time as you bring it up to brazing temp. Seems to me there was some discussion of the issues in "The Oxy-Acetylene Handbook".
I ran into this on older tractor cases and pumps several times while doing repair work for farmers. Finally learned how to factor in the time required to burn out the oil.
I repaired several cast water pump with little problem so the pressure will probably not be the issue that frustrates.

Griffy

 

[arunmrao]

Most probably the housing will be plain carbon steel WCB grade. You can use appropriate low carbon welding rods for weld repairs. However I doubt if you get a good weld in the presence of oil contaminated surfaces. Try and replace with a new one of possible or fabricate a simpler one.

" All that is necessary for triumph of evil is that good men do nothing".
Edmund Burke

 

[Metalfixer]

Hydmech,
If the housing is cast steel, it can be welded using E7018 electrodes. I would drill a small hole at each end of the crack before welding or brazing to prevent further cracking.
The housing might be cast iron, the way that I identify cast iron from cast steel is the size of the fillets on the casting, cast steel has smaller fillets and sharper corners.
Drilling cast steel produces a normal continuous chip and cast iron produces powdery chips.
If it is cast iron, brazing would be your best choice, grind out the crack for full penetration.

Larry