Avaliação da susceptibilidade a trincas a frio induzidas por hidrogênio em juntas soldadas dos aços API 5L X-80 por meio do teste de implante.

Abstract

In this study, the influence of the parameters, process and welding procedures on susceptibility to hydrogen induced cold cracking in API 5L X80 steel welded joints . Were evaluated for this Implant Test using SMAW and FCAW process with different parameters and welding procedures. Were used AWS E 91T8-K8 with 1,60 mm diameter self protected and AWS E 91T1-G with 1,20 mm diameter gas protected . And AWS E 8010 e AWS E 8018-G, with diameter 4,00 mm. After welding the specimens were cut and cracks and microcracks were identified for each welding condition and the results associated with the microstructure and microhardness value in the region where cracking occurred. It was verified that all cracks occurred were predominantly composed of Bainite and Primary Ferrite All cracks were intergranular but do not represented a significant size, as all the microhardness values were less than 238,1 HV it is possible to say that the steel studied has a good weldability and it is not likely to be susceptible to hydrogen induced cold cracking for the analyzed conditions