The Role of the Strain Hardening Exponent in Stress Corrosion Cracking of a High Strength Steel

Abstract

Stress corrosion testing of a vanadium modification of 4340 alloy was conducted using precracked specimens in a cantilever beam apparatus. Plastic zones at the crack tip were determined using optical interference measurements, and the effect of these plastic zones on the fracture paths was demonstrated. Crack propagation rates were measured for steels of varying yield strengths (140–205 ksi). Electron fractographs and photomicrographs associated with the fracture through plastic zone are presented. Crack propagation rates were shown to vary inversely with the yield strength of the steel with the overall failure time being related to both the propagation rate and the fracture toughness of the material.

A three-dimensional multiscale model of intergranular hydrogen-assisted cracking

“…For applied stress-intensity factors below 13.7 MPa ffiffiffiffi m p no crack propagation was computed after 10 6 seconds. This threshold behavior is consistent with experimental observation [56][57][58][59]. At applied stress-intensity factors larger than 41.2 MPa ffiffiffiffi m p , the crack exhibits runaway growth and no equilibrium crack length is found by dynamic relaxation, as expected for applied stress-intensity factors approaching the toughness of the material, K Ic ¼ 58.4 MPa ffiffiffiffi m p .…”

A quantum-mechanically informed continuum model of hydrogen embrittlement

“…Ganglo separated the results between aqueous and gaseous environments, and we show the ranges of K SCC for both cases. A lower slope is observed * * (Colangelo and Ferguson, 1969); * , 4130, H 2 O, 40 MPa √ m, (Nelson and Williams, 1977); ♦, 0:1 N H 2 SO 4 , 40 MPa √ m (Hirose and Mura, 1984a); /, 4340, 3.5% NaCl (Lisagor, 1984); ., 4340, H 2 O (Simmons et al, 1978); M, H11, H 2 O (Johnson and Willner, 1965);+, 4340, H 2 O (van der Sluys, 1969); ×, 4340, H 2 O (Vogt, 1997); ⊗, 4340 (Carter, 1971a); ⊕, 4340-Si, 3.5% NaCl (Carter, 1969); ?, 4340-Si, 3.5% NaCl (Carter, 1969); , 4340, H 2 O (Carter, 1971b); , 4340, 3:0 N NaCl (Carter, 1971b).…”

“…11, along with several experimentally determined curves for AISI 4340 in aqueous solutions (Hirose and Mura, 1984a; (Simmons et al, 1978); M, 1379 MPa, 3.5% NaCl (Colangelo and Ferguson, 1969); , 1282 MPa, 3.5% NaCl (Colangelo and Ferguson 1969); /; ., 1240 MPa, 3.5% NaCl (Lisagor, 1984). Simmons et al, 1978;Colangelo and Ferguson, 1969;Lisagor, 1984). It is apparent that the scatter in the experimental data is quite considerable, and it may lead to particular experiments opposing the general trend (e.g., compare curves for 1344 and 1379 MPa).…”

A phase-field model for solute-assisted brittle fracture in elastic-plastic solids

“…• one application of the model to simulate the hydrogen assisted cracking problem of a sustained load test and different steels. Simmons et al (1978) and − CF 1379 MPa by Colangelo and Ferguson (1969). We have not intended to rigorously reproduce experimental data, but to investigate the model capacity to simulate subcritical crack growth using the general thermodynamical formulation described in the first part of the paper.…”