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ASSISTED CRACK GROWTH IN MARAGING STEEL WELDS BY GASEOUS HYDROGEN
Author(s) -
Tsay L. W.,
Huang W. B.,
Chen C.
Publication year - 1997
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1111/j.1460-2695.1997.tb01545.x
Subject(s) - materials science , maraging steel , hydrogen embrittlement , hydrogen , metallurgy , paris' law , intergranular fracture , austenite , embrittlement , intergranular corrosion , cracking , fracture (geology) , alloy , crack closure , composite material , fracture mechanics , microstructure , corrosion , chemistry , organic chemistry
— The effects of environmental hydrogen content on fatigue crack growth rates (FCGRs) in T‐250 maraging steel plates and laser welds were investigated. The influence of ageing treatments on fatigue characteristics of the alloy was also studied. Experimental results revealed that the accelerated FCGRs in the presence of hydrogen were always associated with changes in fracture modes that appear in compact‐tension specimens. Even for overaged specimens with excellent resistance to gaseous hydrogen embrittlement, such an acceleration of crack growth in hydrogen could not be avoided. The crack path of underaged specimens in hydrogen was found mainly along prior austenite boundaries for steel plates and along coarse columnar boundaries for welds. In gaseous hydrogen, peak‐aged welds exhibited intergranular and quasi‐cleavage mixed fracture modes, compared to mainly quasi‐clevage for similar aged steel plates. Hence, the enhancement of crack growth in hydrogen was more pronounced for the welds. Overaged welds showed higher FCGRs than the same aged steel plates only in hydrogen and for Δ K values greater than 20MPa√m.