In-service operating conditions affecting on weld HAZ hardness for API5L Gr.B pipe steel maintenance.Supolchai Kwankaew, Rittichai Paoniam, Bovornchok Poopat and Sermsak SrisutrapornMATEC Web Conf., 192 (2018) 01042DOI: https://doi.org/10.1051/matecconf/201819201042