[2]AwsDI.1/D1.1M,Structuralweldingcodesteel[3]ANSI/AWSB2.1,Specificationforweldingprocedureandperformancequalification[4]AsNTRPsNT—Tc一1A,Personnelqualificationa
AWSB2.12005SpecificationforWeldingProcedureandPerformanceQualification AWSB2.1BMG2005BaseMetalGroupingforWeldingProcedureandPerformanceQualification AWSB2
.