{"id":{"repo_id":"rgu","oai_identifier":"oai:rgu-repository.worktribe.com:2807379"},"canonical_url":"https://search.dev.ndltd.org/etd/rgu/oai:rgu-repository.worktribe.com:2807379","repository":{"repo_id":"rgu","name":"Robert Gordon University","base_url":"https://rgu-repository.worktribe.com/oaiprovider"},"display":{"title":"Weldability and hydrogen relationships in super duplex stainless steel.","abstract":"As the microstructure of commercial duplex stainless steels consists of approximately 50% austenite and 50% ferrite, the response of these two phases to hydrogen is of interest to the users of these materials. A study has been made of the hydrogen cracking behaviour in welded super duplex stainless steel using the GTA welding process. The aim of this work was to determine the effects of diffusible hydrogen levels and cracking sensitivity in super duplex stainless steel. Based upon the study of influential factors in hydrogen induced cold cracking, this work concentrates on this relationship in the super duplex stainless steel ZERON 100. The hydrogen concentration model was established and the relationship between hydrogen diffusivity and temperature in ZERON 100 was investigated. Four different hydrogen levels were produced in ZERON 100 by the GTA welding process. The hydrogen concentrations were measured at 950°C by Leybold-Heraeus hydrogen analyzer. Using these four hydrogen levels, a restraint Tekken test was carried out (according to the Japanese Industrial Standard JIS Z 3158) to examine hydrogen induced cracking properties after welding. Two parent materials were used in the Tekken tests. They were ZERON 100 (with thicknesses of 13, 20 and 25 mm) and, high ferrite ZERON 100 (with thicknesses of 13 and 20 mm). Two welding consumables were also used. They were ZERON 1OOX (which produces a 50%-50% balanced weld for ZERON 100), and ZERON 1OOM which can obtain higher ferrite percentages in the weld deposit. Further, the effect of hydrogen on mechanical properties, such as strength and ductility were investigated, using slow strain rate tests in a ZERON 100 joint welded with ZERON 1OOX consumable. The cracking mechanism itself was also investigated. Following analyses of the microstructure in weldments and the phase balance between ferrite and austenite, the cracking form and influential factors on cracking were discussed. It was found that cracking was caused not only by hydrogen diffusion but also from a high percentage of ferrite in the microstructure. The main conclusions are as follows: 1. Hydrogen concentration, phase balance and welding restraint influence the propensity to hydrogen induced cracking in ZERON 100. 2. The diffusible hydrogen level depends on measured extraction temperature. The ideal extraction temperature for duplex stainless steels is about 950°C. The higher the ferrite percentage in the weldment or the higher the restraint level of welds in ZERON 100, the lower the critical diffusible hydrogen concentration causing cracking. 3. Hydrogen diffusivity is low in both duplex and super duplex stainless steels. The relationship between diffusivity and temperature in ZERON 100 can be expressed as D = 1.51 X 10 to the power of -3 exp (-47900/RT) Heat treatment at low temperature is not effective and sometimes causes detrimental intermetallic phases. Therefore, solution annealing and quenching is an effective method of removing hydrogen. 4. Hydrogen induced cracking in super duplex weld takes transgranular form. If the hydrogen concentration is below a certain level for a given restraint and ferrite percentage, the cracking propagation will be blocked by the austenitic phase. 5. Restraint Tekken tests show that cracking is more likely to take place from the sites of higher stress concentration, higher ferrite percentage and higher hydrogen concentration. 6. The hydrogen has little effect on the tensile strength and hardness properties of duplex and super duplex stainless steels. However, it may change other mechanical properties, such as charpy impact toughness, elongation, and reduction in area of these materials.","abstract_html":"As the microstructure of commercial duplex stainless steels consists of approximately 50% austenite and 50% ferrite, the response of these two phases to hydrogen is of interest to the users of these materials. A study has been made of the hydrogen cracking behaviour in welded super duplex stainless steel using the GTA welding process. The aim of this work was to determine the effects of diffusible hydrogen levels and cracking sensitivity in super duplex stainless steel. Based upon the study of influential factors in hydrogen induced cold cracking, this work concentrates on this relationship in the super duplex stainless steel ZERON 100. The hydrogen concentration model was established and the relationship between hydrogen diffusivity and temperature in ZERON 100 was investigated. Four different hydrogen levels were produced in ZERON 100 by the GTA welding process. The hydrogen concentrations were measured at 950°C by Leybold-Heraeus hydrogen analyzer. Using these four hydrogen levels, a restraint Tekken test was carried out (according to the Japanese Industrial Standard JIS Z 3158) to examine hydrogen induced cracking properties after welding. Two parent materials were used in the Tekken tests. They were ZERON 100 (with thicknesses of 13, 20 and 25 mm) and, high ferrite ZERON 100 (with thicknesses of 13 and 20 mm). Two welding consumables were also used. They were ZERON 1OOX (which produces a 50%-50% balanced weld for ZERON 100), and ZERON 1OOM which can obtain higher ferrite percentages in the weld deposit. Further, the effect of hydrogen on mechanical properties, such as strength and ductility were investigated, using slow strain rate tests in a ZERON 100 joint welded with ZERON 1OOX consumable. The cracking mechanism itself was also investigated. Following analyses of the microstructure in weldments and the phase balance between ferrite and austenite, the cracking form and influential factors on cracking were discussed. It was found that cracking was caused not only by hydrogen diffusion but also from a high percentage of ferrite in the microstructure. The main conclusions are as follows: 1. Hydrogen concentration, phase balance and welding restraint influence the propensity to hydrogen induced cracking in ZERON 100. 2. The diffusible hydrogen level depends on measured extraction temperature. The ideal extraction temperature for duplex stainless steels is about 950°C. The higher the ferrite percentage in the weldment or the higher the restraint level of welds in ZERON 100, the lower the critical diffusible hydrogen concentration causing cracking. 3. Hydrogen diffusivity is low in both duplex and super duplex stainless steels. The relationship between diffusivity and temperature in ZERON 100 can be expressed as D = 1.51 X 10 to the power of -3 exp (-47900/RT) Heat treatment at low temperature is not effective and sometimes causes detrimental intermetallic phases. Therefore, solution annealing and quenching is an effective method of removing hydrogen. 4. Hydrogen induced cracking in super duplex weld takes transgranular form. If the hydrogen concentration is below a certain level for a given restraint and ferrite percentage, the cracking propagation will be blocked by the austenitic phase. 5. Restraint Tekken tests show that cracking is more likely to take place from the sites of higher stress concentration, higher ferrite percentage and higher hydrogen concentration. 6. The hydrogen has little effect on the tensile strength and hardness properties of duplex and super duplex stainless steels. However, it may change other mechanical properties, such as charpy impact toughness, elongation, and reduction in area of these materials.","abstract_has_math":false,"creators":["Fang, Peijun"],"institution":"Robert Gordon University","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["D. Kirkwood, L.J. Power and C.F.G. Baxter"],"committee_chairs":[],"committee_members":[],"year":1995,"date_issued":"1995","date_published":"1995","updated_at":"2026-07-24T04:10:09Z","subjects":["Duplex stainless steel","GTA welding process","Weld cracks","Zeron 100","Hydrogen concentration","High ferrite","Tekken tests"],"languages":["en"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["oai:rgu-repository.worktribe.com:2807379","https://doi.org/10.48526/rgu-wt-2807379"],"render_values":[{"text":"oai:rgu-repository.worktribe.com:2807379","href":null,"code":true},{"text":"https://doi.org/10.48526/rgu-wt-2807379","href":"https://doi.org/10.48526/rgu-wt-2807379","code":true}]}]},"links":{"outbound_url":"https://rgu-repository.worktribe.com/2807379/1/FANG%201995%20Weldability%20and%20hydrogen%20relationships","outbound_label":"Repository record","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["D. Kirkwood, L.J. Power and C.F.G. 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A study has been made of the hydrogen cracking behaviour in welded super duplex stainless steel using the GTA welding process. The aim of this work was to determine the effects of diffusible hydrogen levels and cracking sensitivity in super duplex stainless steel. Based upon the study of influential factors in hydrogen induced cold cracking, this work concentrates on this relationship in the super duplex stainless steel ZERON 100. The hydrogen concentration model was established and the relationship between hydrogen diffusivity and temperature in ZERON 100 was investigated. Four different hydrogen levels were produced in ZERON 100 by the GTA welding process. The hydrogen concentrations were measured at 950°C by Leybold-Heraeus hydrogen analyzer. Using these four hydrogen levels, a restraint Tekken test was carried out (according to the Japanese Industrial Standard JIS Z 3158) to examine hydrogen induced cracking properties after welding. Two parent materials were used in the Tekken tests. They were ZERON 100 (with thicknesses of 13, 20 and 25 mm) and, high ferrite ZERON 100 (with thicknesses of 13 and 20 mm). Two welding consumables were also used. They were ZERON 1OOX (which produces a 50%-50% balanced weld for ZERON 100), and ZERON 1OOM which can obtain higher ferrite percentages in the weld deposit. Further, the effect of hydrogen on mechanical properties, such as strength and ductility were investigated, using slow strain rate tests in a ZERON 100 joint welded with ZERON 1OOX consumable. The cracking mechanism itself was also investigated. Following analyses of the microstructure in weldments and the phase balance between ferrite and austenite, the cracking form and influential factors on cracking were discussed. It was found that cracking was caused not only by hydrogen diffusion but also from a high percentage of ferrite in the microstructure. The main conclusions are as follows: 1. Hydrogen concentration, phase balance and welding restraint influence the propensity to hydrogen induced cracking in ZERON 100. 2. The diffusible hydrogen level depends on measured extraction temperature. The ideal extraction temperature for duplex stainless steels is about 950°C. The higher the ferrite percentage in the weldment or the higher the restraint level of welds in ZERON 100, the lower the critical diffusible hydrogen concentration causing cracking. 3. Hydrogen diffusivity is low in both duplex and super duplex stainless steels. The relationship between diffusivity and temperature in ZERON 100 can be expressed as D = 1.51 X 10 to the power of -3 exp (-47900/RT) Heat treatment at low temperature is not effective and sometimes causes detrimental intermetallic phases. Therefore, solution annealing and quenching is an effective method of removing hydrogen. 4. Hydrogen induced cracking in super duplex weld takes transgranular form. If the hydrogen concentration is below a certain level for a given restraint and ferrite percentage, the cracking propagation will be blocked by the austenitic phase. 5. Restraint Tekken tests show that cracking is more likely to take place from the sites of higher stress concentration, higher ferrite percentage and higher hydrogen concentration. 6. The hydrogen has little effect on the tensile strength and hardness properties of duplex and super duplex stainless steels. However, it may change other mechanical properties, such as charpy impact toughness, elongation, and reduction in area of these materials."]},{"key":"dc:title","label":"Title","values":["Weldability and hydrogen relationships in super duplex stainless steel."]}]}],"canonical_facts":{"dc:contributor.advisor":["D. Kirkwood, L.J. Power and C.F.G. Baxter"],"dc:contributor.sponsor":["British Council"],"dc:creator":["Fang, Peijun"],"dc:date":["1995-03-31"],"dc:date.issued":["1995"],"dc:description.abstract":["As the microstructure of commercial duplex stainless steels consists of approximately 50% austenite and 50% ferrite, the response of these two phases to hydrogen is of interest to the users of these materials. A study has been made of the hydrogen cracking behaviour in welded super duplex stainless steel using the GTA welding process. The aim of this work was to determine the effects of diffusible hydrogen levels and cracking sensitivity in super duplex stainless steel. Based upon the study of influential factors in hydrogen induced cold cracking, this work concentrates on this relationship in the super duplex stainless steel ZERON 100. The hydrogen concentration model was established and the relationship between hydrogen diffusivity and temperature in ZERON 100 was investigated. Four different hydrogen levels were produced in ZERON 100 by the GTA welding process. The hydrogen concentrations were measured at 950°C by Leybold-Heraeus hydrogen analyzer. Using these four hydrogen levels, a restraint Tekken test was carried out (according to the Japanese Industrial Standard JIS Z 3158) to examine hydrogen induced cracking properties after welding. Two parent materials were used in the Tekken tests. They were ZERON 100 (with thicknesses of 13, 20 and 25 mm) and, high ferrite ZERON 100 (with thicknesses of 13 and 20 mm). Two welding consumables were also used. They were ZERON 1OOX (which produces a 50%-50% balanced weld for ZERON 100), and ZERON 1OOM which can obtain higher ferrite percentages in the weld deposit. Further, the effect of hydrogen on mechanical properties, such as strength and ductility were investigated, using slow strain rate tests in a ZERON 100 joint welded with ZERON 1OOX consumable. The cracking mechanism itself was also investigated. Following analyses of the microstructure in weldments and the phase balance between ferrite and austenite, the cracking form and influential factors on cracking were discussed. It was found that cracking was caused not only by hydrogen diffusion but also from a high percentage of ferrite in the microstructure. The main conclusions are as follows: 1. Hydrogen concentration, phase balance and welding restraint influence the propensity to hydrogen induced cracking in ZERON 100. 2. The diffusible hydrogen level depends on measured extraction temperature. The ideal extraction temperature for duplex stainless steels is about 950°C. The higher the ferrite percentage in the weldment or the higher the restraint level of welds in ZERON 100, the lower the critical diffusible hydrogen concentration causing cracking. 3. Hydrogen diffusivity is low in both duplex and super duplex stainless steels. The relationship between diffusivity and temperature in ZERON 100 can be expressed as D = 1.51 X 10 to the power of -3 exp (-47900/RT) Heat treatment at low temperature is not effective and sometimes causes detrimental intermetallic phases. Therefore, solution annealing and quenching is an effective method of removing hydrogen. 4. Hydrogen induced cracking in super duplex weld takes transgranular form. If the hydrogen concentration is below a certain level for a given restraint and ferrite percentage, the cracking propagation will be blocked by the austenitic phase. 5. Restraint Tekken tests show that cracking is more likely to take place from the sites of higher stress concentration, higher ferrite percentage and higher hydrogen concentration. 6. The hydrogen has little effect on the tensile strength and hardness properties of duplex and super duplex stainless steels. However, it may change other mechanical properties, such as charpy impact toughness, elongation, and reduction in area of these materials."],"dc:identifier":["oai:rgu-repository.worktribe.com:2807379","https://doi.org/10.48526/rgu-wt-2807379"],"dc:identifier.uri":["https://rgu-repository.worktribe.com/2807379/1/FANG%201995%20Weldability%20and%20hydrogen%20relationships"],"dc:language":["en"],"dc:publisher.institution":["Robert Gordon University"],"dc:relation.isreferencedby":["https://rgu-repository.worktribe.com/output/2807379"],"dc:subject":["Duplex stainless steel","GTA welding process","Weld cracks","Zeron 100","Hydrogen concentration","High ferrite","Tekken tests"],"dc:title":["Weldability and hydrogen relationships in super duplex stainless steel."],"dc:type":["Thesis"]},"updated_at":"2026-07-24T04:10:09Z"}