Hi Ajay,
Deposition of tungsten carbide is very hard with little or no ductility. It's advisable to know what's is the matrix (microstructure) and preferably the chemical composition of the deposit.
If a hard alloy in the form of hard facing is deposited by arc welding process then it may crack on shrinkage ,if the there's not enough ductility to accommodate the shrinkage stress/es.
If the deposit required is more than one layer ,use of a barrier layer of austenitic alloy ( E=ER-309 or Inconel 82(ER-NiCr-3) or Inconel 182 (E-NiCrFe-3) could be useful.
You may check with the consumable manufacturer with the problem and see what's their response. More feedback of your end on this subject would be appreciated.
The following AWS article provides good information on effects of various alloying elements on hardfacing deposits/microstructures.
Thanks.
Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist & Consultant
Ontario,Canada.
Email-pgoswami@sympatico.ca,
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of ajay pawse
Sent: Saturday, November 12, 2011 10:15 PM
To: materials-welding@googlegroups.com
Subject: [MW:12956] Cracking problem during Hardfacing (FCAW)
Hello Friends,
We are conducting trials for Tungsten carbide Hardfacing on F-22 material (2.1/4Cr - 1 Mo). we are facing problem of transverse hairline cracks on weldbead. need your help to overcome this problem.
Process: FCAW
Filler wire Dia: 1.2mm
Cuerrent used: during trial we changed current from 87Amps to 140Amps. different runs were taken but all cracked
Volts: 16 to 19.5V
Wire feed: 2.8 to 5m/min
Travel speed: 235 to 600mm/min
Preheat: 120 to 260DegC
Shielding: Argon
With these parameters, we achieved satisfactory weld bead appearance though.
Please let me know if i am missing any factor which is vital for the success of the process. also need you guidance on the parameters i tried.Hope to see your suggestions soon
Please let me know if anyother info is needed.
Thank you.
Regards,
Ajay
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