Materials & Welding

What the Macro Suggests From the image: Fusion is occurring on the upper groove walls. Root area shows an unfused triangular gap / cold lap zone . Weld metal is flowing around the joint rather than penetrating fully to the root. This is typical when the arc cannot adequately reach the root face or root land. Likely Causes 1. Amperage Too Low for Root Pass 82 A for first pass on a restrained joint with 50 mm thick tubesheet may be too low, especially if heat is rapidly absorbed by the heavy SA-516 tubesheet. The tubesheet acts as a heat sink , pulling heat away from the root. 2. Groove Design / Root Land Too Heavy If the groove has: narrow included angle excessive land/root face insufficient tube projection or mismatch then penetration becomes difficult at lower amps. 3. Arc Position / Torch Angle If arc is focused too much on filler or upper bevel edges rather than root corner, fusion at the bottom will be poor. 4. Travel Speed Too F...

Dear Sirs,  As per my below mail history and your recommendation for low Amps to avoid high heat input,  After performing the new MOCKUPs for 15.85, & 19.05 OD SS304L tubes to CS SA-516-70N tubesheet of 50mm with GTAW ER309LMO 1.6 Dia only of 3 passes for 19.05 ID tube, 82 A for 1st pass, 95A for 2nd, 100A for 3rd pass. Only 2 passes given for 15.85 OD tube. We got incomplete penetration aa per the attached macro photo., almost for all the tube welds for both sized tube welds. Please see the groove design for your reference.  Also, please give me suggestions to make sound complete penetration on root pass and to avoid cracks too. Thanks and regards,  Saravanan Sornam,  Ansan city, S.Korea  On Thu, 16 Apr 2026, 2:51 pm 'Ahmed Osman' via Materials & Welding, < materials-welding@googlegroups.com > wrote: ...

Anyone here familiar with Torque Report? Do you have sample template or format? -- https://materials-welding.blogspot.com/ https://www.linkedin.com/groups/122787 --- You received this message because you are subscribed to the Google Groups "Materials & Welding" group. To unsubscribe from this group and stop receiving emails from it, send an email to materials-welding+unsubscribe@googlegroups.com . To view this discussion visit https://groups.google.com/d/msgid/materials-welding/56804463-f63d-47d5-b5ce-c4f1f124c7dcn%40googlegroups.com .

Dear Mr Sridhar, Thanks a lot for your valid reply with acceptable reasons, very nice explanation. good & appreciate your effort.    Regards, Sankaran.SP Welding & Metallurgy expert On Wednesday, 29 April 2026 at 08:53:02 pm IST, sridhar cn <sridharcn305@gmail.com> wrote:  Dear Mr. Sankaran, 1.   For SS 410 (martensitic stainless steel) , PWHT directly affects hardness, toughness, and risk of cracking.   Metallurgical ly SS 410 forms untempered       martensite after welding , so   PWHT is mandatory  in most cases . PWHT is required to temper martensite , reduce hardness, and relieve residual stresses. 2.   Applicable Standards / References:  ASME Section II / IX   – Material & Wel...

What is thickness ? Pl check use of TYP410 S  This Will possible that you will epsilon ate PWHT as I can see typ316  is there on other side . Pl speak to Engineering Team and discuss further  for service conditions of the joint being used . Vishwas  IWE 9823472273 India  On Tue, 17 Mar 2026 at 3:39 PM, Md Usman Ghani < mdushmanghani@gmail.com > wrote: Just for clarification Can any one share, WPS, for ss410 to SS316, On Mon, 2 Mar, 2026, 12:39 pm Sajeersayed Ali, < sajeersayed@gmail.com > wrote: 5.2.2 Combination of WPSs. A combination of qualified and prequalified WPSs may be used without qualification of the combination, provided the limitation of essential variables applicable to each process is observed. On Mon, Mar 2, 2026 at 12:26 PM praba karan < prabakaran776@gmail.com > wrote: ...

Dear PRC, What you’re seeing is a fairly classic situation with tube-to-tubesheet mockups so before changing filler, it’s worth understanding the mechanism. 1) Are these hot cracks? Yes—what you’re describing strongly points to solidification cracking (hot cracking) . Why: They appear at the root and sometimes surface Not detected by PT , but show up after macro etch → typical of tight, interdendritic cracks Occur randomly , not in every weld You’re using austenitic filler (ER309) on a dissimilar joint (likely carbon steel tubesheet + possibly SS tubes) These are textbook indicators of hot cracking during solidification. 2) Likely causes in your case Several contributing factors are probably overlapping: a) Dilution from SA-516 Gr.70 (high carbon steel) Excess dilution into ER309 reduces ferrite in the weld metal Low ferrite (FN < ~3–5) → high hot cracking susceptibility b) Fully austenitic weld metal If yo...