Metallide keevitusprotseduuride spetsifitseerimine ja atesteerimine : keevitusprotseduuri katse. Osa 1, Teraste gaas- ja kaarkeevitus ning nikli ja niklisulamite kaarkeevitus = Specification and qualification of welding procedures for metallic materials : welding procedure test. Part 1, Arc and gas welding of steels and arc welding of nickel and nickel alloys (ISO 15614-1:2004+A1:2008)