Debasis Geirull welding for aged heat resistant austenitic S.S alloys calls for pre-heat at close to 800-900 deg cent and then in pre-heated conditions weld with high current (usually close to 100 A to 200 A) for carburized parts. I am not sure of the success experienced by industry users in this approach. Performing welding with pre-heat maintained at 800-900 deg cent would be a difficult task with heat radiation during welding. The best and successful approach, used for many decades by industry users, had been to perform prior solution anneal at 1150-1200 deg cent the carburized and cracked heat resistant alloy tubes ( in ethylene crackers). This is a well proven approach for success in industry. Edge prepare the solution annealed parts properly and then weld using heat resisitant grade electrodes - after assessing the depth of carburization and oxidation in furnace tubes aged at 1000- 1100 deg cent for > 40,000 hours. This will give for certain a good life close to the same period in which it had served. For the Geirull method, re use success may not be high (my guess) Hope this helps C.V.Srinivasan Nishi Engineers Pvt Ltd India Oct 4, 2008 E-mail: nishi@vsnl.com >does any one having any understanding/ experience about the >methodology and procedure of Gierull Welding method meant >for welding of Aged and carburized heat resistant high >temperature alloys . >Pl. share >regards >