{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/90639"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/90639","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Effect of surface hardening conditions on susceptibility of fasteners to hydrogen embrittlement","abstract":"The goal of this work is to establish the relationship between core hardness, case hardness, and case depth on susceptibility to hydrogen embrittlement of case hardened steel fasteners. While case hardened fasteners have been studied previously, there are currently no processing guidelines supported by quantitative data for fastener standards. Through sustained load and incremental step load embrittlement testing techniques, the susceptibility of case hardened steel tapping screws to internal and environmental hydrogen embrittlement is examined. Further characterization of the fastener samples through microhardness testing, microstructure review, and fracture surface examination allows the determination of susceptibility thresholds. It is shown that core hardness is the primary consideration for susceptibility. However, the fastener surface is prone to failure before the bulk section, up to the case depth, according to the case hardness. The zinc acid electroplating process used to process the fasteners in this study appeared not to induce internal hydrogen embrittlement. Post plating baking operations, however, are shown to lower the threshold strength for embrittlement in high-hardness notched square bars processed on the same plating line.","abstract_html":"The goal of this work is to establish the relationship between core hardness, case hardness, and case depth on susceptibility to hydrogen embrittlement of case hardened steel fasteners. While case hardened fasteners have been studied previously, there are currently no processing guidelines supported by quantitative data for fastener standards. Through sustained load and incremental step load embrittlement testing techniques, the susceptibility of case hardened steel tapping screws to internal and environmental hydrogen embrittlement is examined. Further characterization of the fastener samples through microhardness testing, microstructure review, and fracture surface examination allows the determination of susceptibility thresholds. It is shown that core hardness is the primary consideration for susceptibility. However, the fastener surface is prone to failure before the bulk section, up to the case depth, according to the case hardness. The zinc acid electroplating process used to process the fasteners in this study appeared not to induce internal hydrogen embrittlement. Post plating baking operations, however, are shown to lower the threshold strength for embrittlement in high-hardness notched square bars processed on the same plating line.","abstract_has_math":false,"creators":["Medcalf, John Steven"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"M.S.","degree_level":"Thesis","degree_discipline":"Mechanical Engineering","degree_department":null,"school":null,"contributors":["Thomas, Brian G."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2016,"date_issued":"2016-07-07T19:57:55Z","date_published":"2016-07-07T19:57:55Z","updated_at":"2026-07-22T22:26:34Z","subjects":["hydrogen embrittlement","fasteners","case hardened","tapping screws","surface hardened","zinc electroplating"],"languages":["en"],"rights":["Copyright 2016 John Medcalf"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"http://hdl.handle.net/2142/90639","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Thomas, Brian G."]},{"key":"dc:creator","label":"Author","values":["Medcalf, John Steven"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2016-07-07T19:57:55Z","2016-04-27","2016-05"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Mechanical Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Thesis"]},{"key":"thesis:degree_name","label":"Degree Name","values":["M.S."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["hydrogen embrittlement","fasteners","case hardened","tapping screws","surface hardened","zinc electroplating"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 2016 John Medcalf"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/90639"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The goal of this work is to establish the relationship between core hardness, case hardness, and case depth on susceptibility to hydrogen embrittlement of case hardened steel fasteners. While case hardened fasteners have been studied previously, there are currently no processing guidelines supported by quantitative data for fastener standards. Through sustained load and incremental step load embrittlement testing techniques, the susceptibility of case hardened steel tapping screws to internal and environmental hydrogen embrittlement is examined. Further characterization of the fastener samples through microhardness testing, microstructure review, and fracture surface examination allows the determination of susceptibility thresholds. It is shown that core hardness is the primary consideration for susceptibility. However, the fastener surface is prone to failure before the bulk section, up to the case depth, according to the case hardness. The zinc acid electroplating process used to process the fasteners in this study appeared not to induce internal hydrogen embrittlement. Post plating baking operations, however, are shown to lower the threshold strength for embrittlement in high-hardness notched square bars processed on the same plating line.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2016-07-07 without embargo terms","The student, John Medcalf, accepted the attached license on 2016-04-25 at 11:41.","The student, John Medcalf, submitted this Thesis for approval on 2016-04-25 at 11:48.","This Thesis was approved for publication on 2016-04-27 at 09:15.","DSpace SAF Submission Ingestion Package generated from Vireo submission #9465 on 2016-07-07 at 13:32:54","Made available in DSpace on 2016-07-07T19:57:55Z (GMT). No. of bitstreams: 2 MEDCALF-THESIS-2016.pdf: 2970766 bytes, checksum: e05eb2d28404c14e6361dc42523a52e0 (MD5) LICENSE.txt: 4209 bytes, checksum: 22b37894ee11444ebd376dc10ebf96ba (MD5) Previous issue date: 2016-04-27"]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Effect of surface hardening conditions on susceptibility of fasteners to hydrogen embrittlement"]}]}],"canonical_facts":{"dc:contributor":["Thomas, Brian G."],"dc:creator":["Medcalf, John Steven"],"dc:date":["2016-07-07T19:57:55Z","2016-04-27","2016-05"],"dc:description":["The goal of this work is to establish the relationship between core hardness, case hardness, and case depth on susceptibility to hydrogen embrittlement of case hardened steel fasteners. While case hardened fasteners have been studied previously, there are currently no processing guidelines supported by quantitative data for fastener standards. Through sustained load and incremental step load embrittlement testing techniques, the susceptibility of case hardened steel tapping screws to internal and environmental hydrogen embrittlement is examined. Further characterization of the fastener samples through microhardness testing, microstructure review, and fracture surface examination allows the determination of susceptibility thresholds. It is shown that core hardness is the primary consideration for susceptibility. However, the fastener surface is prone to failure before the bulk section, up to the case depth, according to the case hardness. The zinc acid electroplating process used to process the fasteners in this study appeared not to induce internal hydrogen embrittlement. Post plating baking operations, however, are shown to lower the threshold strength for embrittlement in high-hardness notched square bars processed on the same plating line.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2016-07-07 without embargo terms","The student, John Medcalf, accepted the attached license on 2016-04-25 at 11:41.","The student, John Medcalf, submitted this Thesis for approval on 2016-04-25 at 11:48.","This Thesis was approved for publication on 2016-04-27 at 09:15.","DSpace SAF Submission Ingestion Package generated from Vireo submission #9465 on 2016-07-07 at 13:32:54","Made available in DSpace on 2016-07-07T19:57:55Z (GMT). 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