scholarly journals Microscopic Observation of the Mechanism for Brittle Striation Formation in Low Carbon Steel Fatigued in Hydrogen Gas : TEM and EBSD Observations Corresponding to Fractography

2010 ◽  
Vol 76 (770) ◽  
pp. 1335-1342
Author(s):  
Hide-aki NISHIKAWA ◽  
Yasuji ODA ◽  
Yoshimasa TAKAHASHI ◽  
Hiroshi NOGUCHI
Keyword(s):  
Carbon Steel ◽  
Microscopic Observation ◽  
Low Carbon Steel ◽  
Hydrogen Gas ◽  
Low Carbon

Loading Frequency Effects on the Fatigue Crack Growth Rate and Fracture Surface Morphology of Low Carbon Steel in Case of Long-Term Use in Hydrogen Gas

2011 ◽  
Vol 488-489 ◽  
pp. 323-326
Author(s):  
A. Nishimoto ◽  
Yasuji Oda ◽  
Hiroshi Noguchi
Keyword(s):  
Carbon Steel ◽  
Fracture Surface ◽  
Surface Morphology ◽  
Low Carbon Steel ◽  
Hydrogen Gas ◽  
Loading Frequency ◽  
Fracture Surface Morphology ◽  
Low Carbon ◽  
Frequency Effects

Loading frequency effects on FCGR and fracture surface morphology were investigated on pre-strained low carbon steel in high FCGR range. Loading frequency effects showed the different trend between internal hydrogen and environmental hydrogen. The effects of combined condition hydrogen revealed similar tendency of environmental hydrogen.

Fatigue Crack Growth Characteristics and Effects of Testing Frequency on Fatigue Crack Growth Rate in a Hydrogen Gas Environment in a Few Alloys

2007 ◽  
Vol 567-568 ◽  
pp. 329-332 ◽  
Author(s):  
Kyohei Kawamoto ◽  
Yasuji Oda ◽  
Hiroshi Noguchi
Keyword(s):  
Stainless Steel ◽  
Fatigue Crack ◽  
Carbon Steel ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Low Carbon Steel ◽  
Hydrogen Gas ◽  
304 Stainless Steel ◽  
Low Carbon ◽  
Testing Frequency

In order to investigate the hydrogen effect on fatigue crack growth (FCG) behavior in a few kinds of practical alloys; austenitic stainless steels (solution-treated metastable type 304 and stable type 316L), an aluminum alloy (age-hardened 6061) and a low carbon steel (annealed 0.13%C-Fe), FCG tests were carried out in hydrogen gas and in nitrogen gas. The FCG rates of these materials are enhanced by hydrogen, though the acceleration degrees are different. A crack grows across grains by slip-off in 316L stainless steel and in age-hardened 6061 aluminum alloys even in hydrogen. Faceted area increases in 304 stainless steel and in low carbon steel in hydrogen. In 304 stainless steel, the ratio of facets to the entire fracture surface was not so large. Thus, the FCG rate is not significantly affected through the facets in 304 stainless steel. In low carbon steel, facets were increased considerably, though a crack grows step by step or after a large number of loading cycles even along grain boundaries. Anyhow hydrogen enhances the FCG rate of these materials through the influence on slip behavior. Based on above-mentioned results, the effect of loading frequency on FCG rate in hydrogen of the age-hardened 6061 aluminum alloy was also investigated. The FCG rate increases as the testing frequency decreases, though the FCG rate in hydrogen shows the tendency to saturate.

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