Cracking of Monel 400 TTS welds

[Jeya Prakash]

Dear Experts,

We are facing cracking issues during welding in Monel 400 Tube to Tubesheet Joints. Refer attached photographs.

Tube: SB-163 UNS-N04400; 25.0 mm OD x 2.0 mm thk

Tubesheets: SA-336M Gr F304L + SB-127 UNS-N04400 (48 + 10 mm thick clad)

Welding: ERNiCu-7 GTAW filler wire with Ar shielding gas.

crack locations: weld toe on tube side, tube ends.

Kindly share the reason for such cracking, and precautions required during Monel 400 welding.

Thanks in Advance.

Regards,

Jeya Prakash. J

[Kannayeram Gnanapandithan]

over heated

THANKS & BEST REGARDS,

KG.PANDITHAN, BE, IWE,  CSWIP 3.1,

ISO 9712 Level 2 in VT,

ASNT-Level II in PT,MT,RT & UT,

LA ISO 9001-2015,

International Welding Engineer. 

CONSULTANT-WELDING & QUALITY

Mobile no: +919940739349

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[Ahmed Osman]

Dear friend ,

this may be related to high heat input especially the cracks location in photos mention the points of doubled heated times .

high temp. with Ni/Cu alloys make carbides precipitate easier leading to cracks also coarse grain size which increase with heat have more tendency to crack as precipitation area increase

Best Regards ,

AWS CWEng.   Ahmed Osman 

[Jeya Prakash]

Dear Experts,

Thank you all for the reply.

As an alternate option we are planning to change the tubes from Monel 400  to SA 789 S3750 Super duplex tube.

Kindly suggest the filler wire for welding this dissimilar joint.

Whether it is feasible to weld this dissimilar joint.

Thanks in Advance.

Regards,

Jeya Prakash. J

On Mon, Aug 30, 2021 at 4:07 PM Chiranjeevi A <chiranjee...@gmail.com> wrote:

Dear Jeya,

  It is due to high heat input

Regards

Anil

[Kannayeram Gnanapandithan]

Super duplex spec may be SA789 S32750

Filler wire ER 2509 or ER NiCrMo3

Heat input shall be within 0.5 to 1.5kj/mm

Interpass shall not exceed 100 deg celsius

THANKS & BEST REGARDS,

KG.PANDITHAN, BE, IWE,  CSWIP 3.1,

ISO 9712 Level 2 in VT,

ASNT-Level II in PT,MT,RT & UT,

LA ISO 9001-2015,

International Welding Engineer. 

CONSULTANT-WELDING & QUALITY

Mobile no: +919940739349

To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/CAL5WJhepvvN52_fQ3UtaHToqEcv3%3DGLZdbEAjs86indhPUmMaw%40mail.gmail.com.

[Ahmed Eissa]

Please advise shell and tube side services or share the data sheets to bitter advise the suitability of such dissimilar joint as other operating and design conditions shall be validated 

Sent from Yahoo Mail on Android

On Tue, Aug 31, 2021 at 5:58 AM, Jeya Prakash

<jeyapr...@gmail.com> wrote:

To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/CAL5WJhepvvN52_fQ3UtaHToqEcv3%3DGLZdbEAjs86indhPUmMaw%40mail.gmail.com.

[Vanchinath S.A.]

welding of super duplex tube to monel clad tubesheet-  filler wire ER Ni Cr Mo-14/13/3

regards

vanchi

To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/CAL5WJhepvvN52_fQ3UtaHToqEcv3%3DGLZdbEAjs86indhPUmMaw%40mail.gmail.com.

[Rajnish Dixit]

Hi JP,
Monel being critical material from welding point of view, we have to take care of general good engineering practices like sequence of welding, proper shielding by inert gas, control of heat input, the gap (if any) between tube and tube sheets, etc. In sequence of welding try to weld the joint in multiple segments with sufficient overlaps from starting to end points. Many time the cracks develops due to minor things those are very critical to particular materials.

Thanks,
Best Regards,
Rajnish Dixit