Limitations of the Slow Strain Rate Test for Stress Corrosion Cracking Testing

The effects of grain boundary carbide density and strain rate on the stress corrosion cracking behavior of cold rolled Alloy 690

“…The slow strain rate tensile (SSRT) test is an attractive option for assessing the SCC initiation susceptibility of a resistant material like Alloy 690 because the test time is relatively short compared to a constant load test or crack-propagation test [22], and it involves dynamic loading, which appears to be important in initiating intergranular SCC cracks. Some work [23,24] [25] indicated that slower strain rate induced higher percentage of SCC area on the fracture surface of Alloy 600 strained to failure in 365°C primary water environment.…”

Slow strain rate testing for monitoring cracking of mild steels for vessels and pipes for processing using caustic solutions

“…If the strain rate is too high, the specimen fails predominantly under mechanical loading, with the environment having little opportunity to play any significant role at the crack tip. On the contrary, at too low a strain rate the passive film formed over a longer period of time is too robust to be ruptured by the low strain rate [15,16]. This present study suggests that for the given mild steel in 20 wt% caustic solution at 120 8C, 3.0!10 K7 s K1 is the suitable strain rate for maintaining the crack-tip within the narrow window of caustic cracking susceptibility.…”

Gaseous hydrogen embrittlement of PH 13-8 Mo steel

“…A slow extension rate tensile test is often utilized to determine the deteriorated tensile properties of an alloy in hydrogencontaining environments [12,15]. As a result, this test can be applied to evaluate the relative HE susceptibility of different alloys.…”