Welding Deformation Control of Bottom Mounted In-Core Instrumentation Thimble Guide Columns in Reactor Internals

To the welding deformation of instrumentation thimble guide columns made of austenitic stainless steel,the paper put forward some measures to control the welding deformation,including optimizing the welding procedure and welding parameter.According to the improved welding procedure,no penetrant indications and radiographic defects appear after welding.Besides,welding deformations reduce greatly and no positional tolerance and dimension tolerance are out of the requirements.The improved welding procedure fully meets the design requirement.