Materials & Welding

Yes, literature is available, but looking for actual production experience as normally martensitic SS.  , weld overlay is not performed.  Regards, Sent from Yahoo Mail for iPhone On Monday, May 11, 2026, 4:04 PM, sridhar cn <sridharcn305@gmail.com> wrote:   Though I have not done actual overlay, what I could gather from the available literature is that,  F6NM Stainless Steel weld overlay is   commonly   done in hydro turbine parts, valve internals,  and  pump sleeves   . The success of overlay depends much  more on dilution  control,   hydrogen control, and post-weld hardness management than on the actual deposition process itself.  F6NM / CA6NM  is  a  P6, air hardening l ow carbon martensitic stainless steel  with a pprox. 13%...

What problems are you expecting to face during pre and post overlay welding operations?  You have not yet spelled out whether it will be Stellite, Ni based or SS based overlay and on what thickness?  Could mention only the expected problems and precautions /solutions to avoid them in advance.  Unless the actual welding (PQR) is done, we will not know what practical problems to face.  Think you can guide us with your experience. All the Best!! rgds, On Mon, 11 May 2026 at 22:32, 'manish kulkarni' via Materials & Welding < materials-welding@googlegroups.com > wrote: Yes, literature is available, but looking for actual production experience as normally martensitic SS.  , weld overlay is not performed.  Regards, Sent from Yahoo Mail for iPhone On Monday, May 11, 2026, 4:04 PM, sridhar cn < sridharcn305@gmail.com > wrote: ...

1. Use Preheat of 150degC to 250degC. Higher preheat temperature may result in retained Austenite and also upon overlay cool it to Room temperature or temperature below the Mf (Martensite finish temperature). 2. Use ER/ENiCrMo3 for the barrier layer as well as remaining passes. 3. Perform PWHT at least 30degC below the Material tempering temperature to avoid softening due to coarsening of carbides or pearlite spherodization. 4. Post heat at 300degC after welding may be beneficial to drive away Hydrogen. Thanks & Regards J.Gerald Jayakumar 0091-8838619635 On Tuesday, 12 May 2026 at 05:12:45 pm IST, 'manish kulkarni' via Materials & Welding <materials-welding@googlegroups.com> wrote: We are qualifying PQrs for 625 WO on F6 Nm.   I foresee risk due to micro structure changes due to higher PWHt temp against tempering temp of ...