| Dear Mr.Narendra Gohil, In the table QW-353 & QW-356 for base metal variable you have to look after QW 403.18 which states as follow, QW-403.18 A change from one P-Number to any otherP-Number or to a base metal not listed in table QW/QB- 422, except as permitted in QW-423, and in QW-420.2. Finally regarding the base metal qualification for welder you have to follow QW-423 as per SEC IX. Regards, P.B.R P.BalajiRajan, Inspection Engineer, Velosi Certification LLC, P.O 3408 Doha-Qatar. -------Original Message------- From: Narendra Gohil Date: 3/19/2011 12:17:19 PM Subject: Re: [MW:10429] Welder's qualification for diffrent steels and steel alloys. That means mainly we have to follow QW-353(SMAW) or QW 356(GTAW) for welder qualification.And that clearly mentioning P no as essential variable for the base metals. So here even if my welder is qualified with CS.I have to go for separate qualification for low alloy steel as P no. is changing. Kindly correct me if my understanding is not correct. Thanks & rgds Narendra Gohil Welding Engineer QAFCO Ph.+974-44228289(O) From: Sukamal Naskar <sukamalbecmet@gmail.com> To: materials-welding@googlegroups.com Cc: Narendra Gohil <ngohil@qafco.com.qa> Date: 19/03/2011 11:52 Subject: Re: [MW:10428] Welder's qualification for diffrent steels and steel alloys. Sent by: materials-welding@googlegroups.com Dear Mr. Gohil, Whenever you will qualify any welder, you have to consider all the essential variables QW353, QW356. The F-No will chage for SMAW , and for GTAW may be the F-No wil be same. If all the essential variables of QW 353 (SMAW) and QW 356 (GTAW) dosen't change , then you can qualify the welders accordingly. Kind Regards, Sukamal Naskar Senior Welding Engineer Bohler Welding On Sat, Mar 19, 2011 at 11:36 AM, Narendra Gohil <ngohil@qafco.com.qa> wrote: Dear Experts, As per ASME sec.IX- QW423.1 mentioning Base metals for welder qualification and also mentioning qualified production base metals against that. Like; P-or S-No.1through P -or S- No.11,P- or S-No. 34,and P- or S-No.41 through P- S-No.49 and against that same grouping and range of P- or S-No. mentioned for qualified production base metals. That means if a welder qualified with as for example in CS(P no-1) welding(GTAW or SMAW any one ) with preheating and PWHT welding parameters,he can qualified with Low alloy steel like (P.No.4 or other in low alloy steel). I have been questioned by our Inspection experts and I don't have answer other than mentioned in QW401.2"essential variable"(Performance). Thanks & Rgds. Narendra Gohil Welding Engineer QAFCO Ph.+974-44228289(O) -- To post to this group, send email to materials-welding@googlegroups.com To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com For more options, visit this group's bolg at http://materials-welding.blogspot.com/ The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents. -- Sukamal -- -- To post to this group, send email to materials-welding@googlegroups.com To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com For more options, visit this group's bolg at http://materials-welding.blogspot.com/ The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents. |
Introduction The colour formed when stainless steel is heated, either in a furnace application or in the heat affected zone of welds, is dependent on several factors that are related to the oxidation resistance of the steel. The heat tint or temper colour formed is caused by the progressive thickening of the surface oxide layer and so, as temperature is increased, the colours change. Oxidation resistance of stainless steels However, there are several factors that affect the degree of colour change and so there is no a single table of colour and temperature that represents all cases. The colours formed can only be used as an indication of the temperature to which the steel has been heated. Factors affecting the heat tint colours formed Steel composition The chromium content is the most important single factor affecting oxidation resistance. The higher the chromium, the more heat resistant the steel and so the development of the heat tint colou...
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