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[MW:6531] Welding of SS 304/321 for pressure vessel application

By Materials & Welding

In addition for E347/ER347:

Consumables depositing titanium as a stabilizing element are not commercially available because titanium is not readily transferred across the arc in shielded metal arc welding. Tantalum and niobium are almost equally effective in stabilizing carbon and in providing high-temperature strength.

From: chander bhushan girotra [mailto:chandergirotra@gmail.com]
Sent: Monday, August 16, 2010 11:08 PM
To: mlkthakkar2@gmail.com
Cc: Bathula Raghuram (Mumbai - PIPING)
Subject: reply to your query

SS E308 is a 19;9 grade electrode recommended for welding 304 the 18;8 grade base material.Reason why a higher alloyed consumable is used is to provide for vapourisation losses during and  also provide safety against lack of homogenity in weld metal. Weld metal is deposited at high speed and behaves like cast structure hence is bound to be less homogenous.A richer ally will avoid such imbalance  and avoid corrosion.
 
There fore all grades of SMAW electrodes and filler wires have a bit higher Cr,Ni and Mo.
 
C C Girotra
Weldwell Speciality Pvt Ltd
Mumbai

-----Original Message-----

From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of MAULIK

Sent: Sunday, August 15, 2010 3:15 PM

To: Materials & Welding

Subject: [MW:6502] Welding of SS 304 for pressure vessel application

Dear all,

1. Why E 308 is used for welding of SS 304 instead of E 304?

2. Why E 307 is used for welding of SS 321 instead of E 321?

Of course E 321 & E 304 electrodes are not available in market.

Is there any metallurgical reason or any manufacturing difficulty?

Please give the answer with proper justification.

Regards,

Maulik H. Thakkar

Welding Engineer


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