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Re: [MW:31906] Continuous crack in forged duplex ring by PAW process

By Materials & Welding
Dears ,

ERCoCr-B need more preheat (about 400c) ... may be 1st layer not cracked as dilution with base metal change the carbides% which led to little hardness comparing with the 2nd layer... this ERCoCr-B give a very high hardness results than ERCoCr-E which have little carbon but give little hardness comparing with ERCoCr-B .

U can preheat ( but take care of duplex heating problems ) and try to keep cooling rate as low as possible .. or try one layer giving u the needed thickness ... or go to another electrode with little hardness
   

Best Regards ,
Ahmed Osman



On Saturday, January 2, 2021, 06:23:16 p.m. GMT+3, SURESH <qms.pjgpl@gmail.com> wrote:


Dear Experts
Need all your experience sharing on the below problem.

Material: ASTM A182, F55
Process: PAW
Welding: Hard facing weld overlay
Consumable ERCoCr-B (Stellite 12)
Layer deposited: 2 Layers
Deposition thick: 3 to 4mm ERCoCr-B on Base material
Interpass maintained: 150*C

During weld deposition of PAW process on 2nd layer itself crack has been propagated. We tried to rework by grinding and touch up, from that moment crack has been developed. If we tried to attend the crack place, other place are developing crack. Also now we again tried to rework, crack has been developing all the place, kindly tell me where this goes wrong?????

We are confused to do rework. As we goes deep to remove the crack, so we tried to grind 4mm deep now again deposited ER2594 by Tig process and then we follwed to weld by ERCoCr-B filler by TIG process. Again crack is developing enormously.

Please give valuable input to overcome from where we goes wrong in this?


REGARDS
SURESH 

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