Mechanical degradation of API X65 pipeline steel by exposure to hydrogen gas

作者：Lee Yun Hee^*; Lee Hae Moo; Kim Yong il; Nahm Seung Hoon

来源：Metals and Materials International, 2011, 17(3): 389-395.

DOI：10.1007/s12540-011-0614-1

• ductility
• embrittlement
• hydrogen
• strain rate
• tensile test

Hydrogen-induced degradations have generally been investigated through the ex situ testing of cathodically hydrogen-charged specimens. However, the cathodic charging cannot realize damage accumulation by gaseous hydrogen in transportation pipelines. Thus, we designed an ampule specimen which enables an in situ tensile test containing gaseous hydrogen. Ampule specimens made of API (American Petroleum Institute) X65 pipeline steel showed significant reductions of 3.4 % and 4.1 %, respectively, in their ultimate tensile strength and fracture strain after exposure to 20 MPa of hydrogen gas. The resulting fracture surface showed quasi-cleavage perpendicular to the loading direction and a fracture thickness close to the initial wall thickness, significantly different from the complex dimples and highly reduced fracture thickness by shear deformations in nitrogen gas and air environments.

• 出版日期2011-6