Impact of high-pressure gaseous hydrogen on the fatigue behaviour of austenitic steel A-286 under asymmetric loading conditions

Ultrasonic techniques are an established means for carrying out fatigue tests at very high numbers of cycles. These techniques are based on the formation of a standing ultrasonic wave in the specimen and usually use frequencies around 20 kHz. Although such systems allow testing to a very high number of cycles in a relatively short time, the use of a standing wave for creating the strains restricts them to symmetric push-pull mode. This limitation can be overcome by coupling an ultrasonic test device to a universal test rig. In this work a different approach is presented that is particularly well suited for studying environmental effects. The load train with the specimen is enclosed in a pressure vessel. An acoustic horn divides this pressure vessel into two separate chambers. Applying a pressure difference between the two chambers then leads to a static stress in the specimen on which the oscillating stress from ultrasonic excitation is superposed. The addition of both stresses allows testing at varying R ratio. The deteriorating effect of high-pressure gaseous hydrogen on the steel A-286 is investigated as function of oscillating and static stresses at room temperature. SEM analysis of the fracture surface is presented.

BRUCHHAUSEN Matthias;  FISCHER Burkhard;  RUIZ MORENO Ana Maria;  HAEHNER Peter;  SOLLER Sebastian; 

2015-09-21

TRANS TECH PUBLICATIONS LTD

JRC93945

1013-9826,   

http://www.scientific.net/KEM.664.156,    https://publications.jrc.ec.europa.eu/repository/handle/JRC93945,   

10.4028/www.scientific.net/KEM.664.156,