Indian Welding Journal

S. C. Chetal ¹, K. V. Ravichandran ¹

Affiliations
1 Nuclear Systems Division, Indira Gandhi Centre, Kalapakkam-603 102, IN

Abstract

Flushing of welds besides providing aesthetic outlook could lead to improved fatigue behaviour. Design rules available in the nuclear codes are brought to the notice of the users of non nuclear design codes. Guidelines are provided in the paper for the welded components where flushing of welds could be specified.

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T. R. Sundaramoorthy ¹, S. C. Chetal ¹

Affiliations
1 Nuclear System Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102, IN

Abstract

The ASME Boiler&Pressure Vessel Code Section VIII o'fers the choice of design and construction of pressure vessels as per Div.1 and Div.2. The Div.1 is more commonly used due to its familiarity with the vessel manufacturers but savings in cost of pressure vessels in many cases can be achieved by using Division 2 for design and construction. [Div.2 calls for detailed design analysis and certain fabrication and inspection procedures to be followed]. With reduced factor of safety on ultimate tensile strength and thus providing higher allowable stress depending on material grade and design temperature, a vessel can be built to Div.2 using thin shells and heads. This results in savings in material cost, fabrication cost and weight This paper deals with the studies made on the comparative cost of pressure vessels designed as per Div.1 and 2 which reveal that Div. 2 rules can be applied economically for a wide range of vessel sizes and pressures.

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S. C. Chetal ¹

Affiliations
1 Nuclear Systems Division, Indira Gandhi Centre for Atomic Research, Kalpakkam:603102, IN

Abstract

Concern expressed in nuclear Codes for weldments creep and fatigue behaviour is brought to the notice of the users of non-nuclear design codes. Guidelines are provided in the paper for improving the life of SS 316 welded components for elevated temperature service.

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S. C. Chetal ¹, P. Chellapandi ¹

Affiliations
1 Nuclear Systems Division, Indira Gandhi Centre for Atomic Research, Kalpakkam-603 102, IN

Abstract

Weldments can be the life-limiting feature of high-temperature components and premature failures of weldments have become a matter of concern in the recent times. In order to allow for the weakening effect of the welas in the design, factors are applied to the parent material properties. The two factors which are of current interest are the fatigue strength reduction factor, and the creep strength reduction factor, although the creep-fatigue strength reduction factor also needs consideration. This paper provides some of the background for these factors and their use in the nuclear as well as non-nuclear pressure vessel design codes. The results of recent works carried out for ferritic steels, austenitic steels and dissimilar metal welds are also brought out.

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V. Balasubramaniyan ¹, S. C. Chetal ¹

Affiliations
1 Indira Gandhi Centre for Atomic Research, Kalpakkam, IN

Abstract

The Technology of Joining metals by welding has undergone considerable developments since its inception The developments an on going process, has been fuelled by demanding application requirements The design methodology of welded joints and fabrication techniques have also evolved with time So is the case with inspection techniques It IS generally agreed that the presence of discontinuities/defects in welded joints is unavoidable The earlier conventional acceptance standards for welds were closely related to

a Achievable standards of good workmanship.

b The detection capability of available inspection methods and

c Supporting evidence of satisfactory performance in service.

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