Effect of absorbed hydrogen on crack-tip ductility in the welded A516 steel
Effects of absorbed hydrogen on structure and properties of welded A516 Grade-70 steel are investigated. Emphasis is placed on ductility measure of the crack-tip plastic zone under Mode I loading. Specimens are cathodically charged in a cell with dilute sulphuric acid and corrosion inhibitor with un...
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| Format: | Conference or Workshop Item |
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2007
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| _version_ | 1796855319337369600 |
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| author | Khattak, M. A. Maslan, M. H. Tamin, M. N. |
| author_facet | Khattak, M. A. Maslan, M. H. Tamin, M. N. |
| author_sort | Khattak, M. A. |
| collection | ePrints |
| description | Effects of absorbed hydrogen on structure and properties of welded A516 Grade-70 steel are investigated. Emphasis is placed on ductility measure of the crack-tip plastic zone under Mode I loading. Specimens are cathodically charged in a cell with dilute sulphuric acid and corrosion inhibitor with uniform charging current density of 20 mA/ cm2 and at different exposure time. Results indicate a change from coarse- to fine-grained microstructures in the weld region and heat affected zone (HAZ) of hydrogen-charged specimen. Well-defined ferrite-pearlite bands in the base metal are transformed into coarse-grain structure. Hardness variation along radial distance indicates higher values towards the center of the bar, possibly due to faster diffusion rate but limited solubility of hydrogen. Load-COD responses indicate that slow, stable crack propagation occurred in both base metal and HAZ. The measured provisional fracture toughness, KQ is higher for HAZ than that for the base metal. The toughness values decreases significantly for the initial three hours of hydrogen charging. The tensile fracture region in the immediate fatigue pre-crack tip forms a triangular (rough) zone due to limited constraint to free surface deformation in the thin specimen. Fracture surface of HAZ is dominated by intergranular fracture with localized cleavage facets. |
| first_indexed | 2024-03-05T18:26:52Z |
| format | Conference or Workshop Item |
| id | utm.eprints-13935 |
| institution | Universiti Teknologi Malaysia - ePrints |
| last_indexed | 2024-03-05T18:26:52Z |
| publishDate | 2007 |
| record_format | dspace |
| spelling | utm.eprints-139352017-08-06T03:17:05Z http://eprints.utm.my/13935/ Effect of absorbed hydrogen on crack-tip ductility in the welded A516 steel Khattak, M. A. Maslan, M. H. Tamin, M. N. TJ Mechanical engineering and machinery Effects of absorbed hydrogen on structure and properties of welded A516 Grade-70 steel are investigated. Emphasis is placed on ductility measure of the crack-tip plastic zone under Mode I loading. Specimens are cathodically charged in a cell with dilute sulphuric acid and corrosion inhibitor with uniform charging current density of 20 mA/ cm2 and at different exposure time. Results indicate a change from coarse- to fine-grained microstructures in the weld region and heat affected zone (HAZ) of hydrogen-charged specimen. Well-defined ferrite-pearlite bands in the base metal are transformed into coarse-grain structure. Hardness variation along radial distance indicates higher values towards the center of the bar, possibly due to faster diffusion rate but limited solubility of hydrogen. Load-COD responses indicate that slow, stable crack propagation occurred in both base metal and HAZ. The measured provisional fracture toughness, KQ is higher for HAZ than that for the base metal. The toughness values decreases significantly for the initial three hours of hydrogen charging. The tensile fracture region in the immediate fatigue pre-crack tip forms a triangular (rough) zone due to limited constraint to free surface deformation in the thin specimen. Fracture surface of HAZ is dominated by intergranular fracture with localized cleavage facets. 2007 Conference or Workshop Item PeerReviewed Khattak, M. A. and Maslan, M. H. and Tamin, M. N. (2007) Effect of absorbed hydrogen on crack-tip ductility in the welded A516 steel. In: National Metallurgical Conference 2007 (NMC 2007), 2007, Johor Bahru. |
| spellingShingle | TJ Mechanical engineering and machinery Khattak, M. A. Maslan, M. H. Tamin, M. N. Effect of absorbed hydrogen on crack-tip ductility in the welded A516 steel |
| title | Effect of absorbed hydrogen on crack-tip ductility in the welded A516 steel |
| title_full | Effect of absorbed hydrogen on crack-tip ductility in the welded A516 steel |
| title_fullStr | Effect of absorbed hydrogen on crack-tip ductility in the welded A516 steel |
| title_full_unstemmed | Effect of absorbed hydrogen on crack-tip ductility in the welded A516 steel |
| title_short | Effect of absorbed hydrogen on crack-tip ductility in the welded A516 steel |
| title_sort | effect of absorbed hydrogen on crack tip ductility in the welded a516 steel |
| topic | TJ Mechanical engineering and machinery |
| work_keys_str_mv | AT khattakma effectofabsorbedhydrogenoncracktipductilityintheweldeda516steel AT maslanmh effectofabsorbedhydrogenoncracktipductilityintheweldeda516steel AT taminmn effectofabsorbedhydrogenoncracktipductilityintheweldeda516steel |