Journal Published Online: 28 August 2014
Volume 4, Issue 2

Microstructurally Mediated Changes in Fracture Characteristics for Electrochemically Hydrogenated 4340 Steel

CODEN: MPCACD

Abstract

The effect of hydrogen on the fracture characteristics of low alloy 4340 steel was studied using double-notched tensile samples electrochemically charged in situ with hydrogen in 1 N H2SO4 + 5 mg/l As2O3 solution. Fracture behaviors of samples with prior austenitic grain sizes of 10 and 40 μm and martensitic hardness of 43–52 HRC (Rockwell hardness, C scale) were examined after hydrogen charging times of 0–40 min. As expected, increases in hydrogen charging time and hardness resulted in decreased failure strains and decreased evidence of ductile fracture. Harder samples showed predominant intergranular fracture close to the notch and a combination of ductile and flat surfaces away from the notch. Softer samples showed mixed mode intergranular and quasi-cleavage fracture close to the notch and predominant ductile fracture as distance from the notch increased.

Author Information

Hassan, Mobbassar Sk
National Center of Excellence for Research in the Intermodal Transport Environment, Materials Engineering, Auburn Univ., Auburn, AL, US
Overfelt, Ruel
National Center of Excellence for Research in the Intermodal Transport Environment, Materials Engineering, Auburn Univ., Auburn, AL, US
Pages: 16
Price: $25.00
Related
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Details
Stock #: MPC20140026
ISSN: 2165-3992
DOI: 10.1520/MPC20140026