1994 年度実績報告書

接合部の強度不均一に注目した高靭性高張力鋼の海洋構造物への適用性評価手法の確立

研究課題

研究課題/領域番号	05302050
研究機関	大阪大学
研究代表者	豊田政男大阪大学, 工学部, 教授 (00029191)
研究分担者	鈴木秀一住友金属工業(株), 鹿島製鉄所・厚板管理室, 室長(研究者) 栗原正好日本鋼管(株), 福山研究所・鋼材研究室, 室長(研究者) 中野善文川崎製鉄(株), 鉄鋼研究所・鋼材研究部, 部長(研究者) 萩原行人新日本製鉄(株), 大分技術研究部, 部長(研究者) 南二三吉大阪大学, 工学部, 助教授 (60135663)
キーワード	高強度鋼溶接部 / 海洋構造物 / 強度ミスマッチング / HAZ靭性 / 継手破壊性能 / 塑性拘束 / CTOD試験 / ローカルアプローチ
研究概要	本研究は、高降伏点TMCP鋼(YP420〜500MPaクラス)の大型海洋構造物への適用拡大を目指し、設計概念ともうまく融合した高降伏点強度鋼の溶接構造における破壊性能評価手順を確立することを目的として実施した。研究の重点は、巨視的に強度・靭性不均質の避けがたい溶接部の破壊靭性評価はいかにあるべきか、また、それらの影響を考慮したときの溶接部材料選択はいかにあるべきかを明らかにすることにあり、解析的・実験的検討によって破壊靭性試験結果と継手破壊性能とを定量的に対応づける手法を開発した。本研究で得られた主な成果は以下のとおりである。母材と溶接金属の強度ミスマッチ、とくに、溶接金属の強度オーバーマッチは、靭性劣化が問題となる溶接熱影響部(HAZ)に次のような影響をもたらす。HAZ靭性が比較的良好な場合には、強度オーバーマッチはHAZで脆性破壊が発生する以前に低強度の母材側に選択的な塑性変形をもたらすため、き裂成長の母材側への湾曲現象が現れ、その結果としてHAZの破壊限界が見かけ上高くなる。しかし、HAZの靭性劣化が著しい場合には、強度オーバーマッチはHAZの塑性変形を拘束し、HAZにおける局部応力を上昇させるために同じ入熱条件で作製した等質継手(溶接金属強度≒母材強度)の場合よりもHAZの破壊発生抵抗を低下させる。溶接継手の破壊性能評価においては、強度ミスマッチによる塑性拘束に加え、評価に用いる試験片の形状や寸法に応じた幾何学的塑性拘束にも注意することが必要で、強度ミスマッチ範囲が25%程度以内ならむしろ後者の幾何学的塑性拘束の影響の方が大きい。本研究では、このような塑性拘束の破壊特性に果たす役割をふまえ、三点曲げ靭性試験結果に基づく継手破壊性能の予測手法を開発するとともに、構造性能確保のための材料の必要破壊靭性値の決定手順を提示した。

研究成果
(19件)

すべてその他

すべて文献書誌 (19件)

[文献書誌] 川端文丸: "鋼溶接熱影響部靭性に及ぼす局部的硬化部の形態効果" 日本造船学会論文集. 第173号. 349-357 (1993)
[文献書誌] Shuichi SUZUKI: "Property Distribution Map to Understand HAZ CTOD Toughness" Proceedings of the 12th Int.Conf.OMAE. Vol.3B. 753-760 (1993)
[文献書誌] Fumiyoshi MINAMI: "Significance of Shallow Notch CTOD Test in Fracture Performance Evaluation of Welded Joint" Proceedings of the 12th Int.Conf.OMAE. Vol.3B. 761-768 (1993)
[文献書誌] 豊田政男: "溶接継手の破壊性能評価のための靭性評価手法に関する考察-Shallow Notch CTOD試験の意義-" 溶接学会論文集. 第11巻. 454-460 (1993)
[文献書誌] Mons HAUGE: "Estimation of Characteristic CTOD Fracture Toughness by Binominal Probability and Weibull Statistics" SINTEF Production Engineering Report STF20 F93159. 1-14 (1993)
[文献書誌] Claudio RUGGIERI: "Effect of Strength Mismatch on Crack Tip Stress Fields of HAZ-Notched joints Subjected to Bending and Tension" 日本造船学会論文集. 第174号. 543-549 (1993)
[文献書誌] Toyoaki SHIWAKU: "Metallurgical Factors on Toughness in Intercritically Reheated HAZ of Low-C Low-Alloy Steel" Proceedings of the 4th Int.Conf.ISOPE. Vol.4. 215-221 (1994)
[文献書誌] Massao TOYODA: "Strength Mis-Matching and Its Influence on the Performance of Welded Structures" Mis-Matching of Welds,ESIS 17,Mechanical Engineering Publications. 335-350 (1994)
[文献書誌] Masao TOYODA: "Fracture Property of HAZ-Notched Weld Joint with Mechanical Mis-Matching-Part I,Analysis of Strngth Mis-Matching of Welds on Fracture Initiation Resistance of HAZ-Notched Joint" Mis-Matching of Welds,ESIS 17,Mechanical Engineering Publications. 399-415 (1994)
[文献書誌] Christian THAULOW: "Fracture Property of HAZ-Notched Weld Joint with Mechanical Mis-Matching-Part II,Effect of Local Mechanical Mis-Matching on Fracture Initiation in Steel Weldment" Mis-Matching of Welds,ESIS 17,Mechanical Engineering Publications. 417-432 (1994)
[文献書誌] Fumiyoshi MINAMI: "Prediction of Specimen Geometry Effect on Fracture Resistance of HAZ-Notched Welds by The Local Approach" Proceedings of the 2nd Workshop on Constraint Effect on the Structural Performance of Welded Joints. 1-10 (1994)
[文献書誌] Fumiyoshi MINAMI: "Effect of Strength Mis-Match on Fracture Mechanical Behavior of HAZ-Notched Weld Joint" Proceedings of the 2nd Workshop on Constraint Effect on the Structural Performance of Welded Joints. 78-86 (1994)
[文献書誌] Christian THAULOW: "Effect of Extraction Procedure on the Fracture Behaviors of HAZ-Notched Welded Joints" Proceedings of the 2nd Workshop on Constraint Effect on the Structural Performance of Welded Joints. 87-100 (1994)
[文献書誌] Fumimaru KAWABATA: "Morphological Effect of Local Hard Zones on Fracture Toughness of Weld HAZ" Proceedings of the 2nd Workshop on Constraint Effect on the Structural Performance of Welded Joints. 126-133 (1994)
[文献書誌] Fumiyoshi MINAMI: "Probabilistic Approach to Link Between Design Concept and Toughness Requirement by The Local Approach" Proceedings of the 2nd Workshop on Constraint Effect on the Structural Performance of Welded Joints. 142-146 (1994)
[文献書誌] Masao TOYODA: "Plastic Constraint Controlling Factors and Their Effect" Proceedings of the 2nd Workshop on Constraint Effect on the Structural Performance of Welded Joints. 147-159 (1994)
[文献書誌] Mons HAUGE: "Estimation Lower Bound CTOD Fracture Toughness of HAZ Notched Welds with Mechanical Mismatch" Proceedings of the 10th European Conference on Fracture,ECF10-Structural Integrity,Experiments,and Applications,. 1037-1049 (1994)
[文献書誌] Christian THAULOW: "Effect of Notch Tip Location in CTOD Testing of the Heat Affected Zone of Steel Weldments" Proceedings of the 10th European Conference on Fracture,ECF10-Structural Integrity,Experiments,and Applications,. 1053-1066 (1994)
[文献書誌] 南二三吉: "強度ミスマッチの影響を考慮した鋼多層溶接熱影響部の破壊靭性評価" 溶接学会論文集. 第12巻. 568-574 (1994)

1994 年度 実績報告書

接合部の強度不均一に注目した高靭性高張力鋼の海洋構造物への適用性評価手法の確立

研究代表者

豊田 政男 大阪大学, 工学部, 教授 (00029191)

研究成果

[文献書誌] 川端文丸: "鋼溶接熱影響部靭性に及ぼす局部的硬化部の形態効果" 日本造船学会論文集. 第173号. 349-357 (1993)

[文献書誌] Shuichi SUZUKI: "Property Distribution Map to Understand HAZ CTOD Toughness" Proceedings of the 12th Int.Conf.OMAE. Vol.3B. 753-760 (1993)

[文献書誌] Fumiyoshi MINAMI: "Significance of Shallow Notch CTOD Test in Fracture Performance Evaluation of Welded Joint" Proceedings of the 12th Int.Conf.OMAE. Vol.3B. 761-768 (1993)

[文献書誌] 豊田政男: "溶接継手の破壊性能評価のための靭性評価手法に関する考察-Shallow Notch CTOD試験の意義-" 溶接学会論文集. 第11巻. 454-460 (1993)

[文献書誌] Mons HAUGE: "Estimation of Characteristic CTOD Fracture Toughness by Binominal Probability and Weibull Statistics" SINTEF Production Engineering Report STF20 F93159. 1-14 (1993)

[文献書誌] Claudio RUGGIERI: "Effect of Strength Mismatch on Crack Tip Stress Fields of HAZ-Notched joints Subjected to Bending and Tension" 日本造船学会論文集. 第174号. 543-549 (1993)

[文献書誌] Toyoaki SHIWAKU: "Metallurgical Factors on Toughness in Intercritically Reheated HAZ of Low-C Low-Alloy Steel" Proceedings of the 4th Int.Conf.ISOPE. Vol.4. 215-221 (1994)

[文献書誌] Massao TOYODA: "Strength Mis-Matching and Its Influence on the Performance of Welded Structures" Mis-Matching of Welds,ESIS 17,Mechanical Engineering Publications. 335-350 (1994)

[文献書誌] Masao TOYODA: "Fracture Property of HAZ-Notched Weld Joint with Mechanical Mis-Matching-Part I,Analysis of Strngth Mis-Matching of Welds on Fracture Initiation Resistance of HAZ-Notched Joint" Mis-Matching of Welds,ESIS 17,Mechanical Engineering Publications. 399-415 (1994)

[文献書誌] Christian THAULOW: "Fracture Property of HAZ-Notched Weld Joint with Mechanical Mis-Matching-Part II,Effect of Local Mechanical Mis-Matching on Fracture Initiation in Steel Weldment" Mis-Matching of Welds,ESIS 17,Mechanical Engineering Publications. 417-432 (1994)

[文献書誌] Fumiyoshi MINAMI: "Prediction of Specimen Geometry Effect on Fracture Resistance of HAZ-Notched Welds by The Local Approach" Proceedings of the 2nd Workshop on Constraint Effect on the Structural Performance of Welded Joints. 1-10 (1994)

[文献書誌] Fumiyoshi MINAMI: "Effect of Strength Mis-Match on Fracture Mechanical Behavior of HAZ-Notched Weld Joint" Proceedings of the 2nd Workshop on Constraint Effect on the Structural Performance of Welded Joints. 78-86 (1994)

[文献書誌] Christian THAULOW: "Effect of Extraction Procedure on the Fracture Behaviors of HAZ-Notched Welded Joints" Proceedings of the 2nd Workshop on Constraint Effect on the Structural Performance of Welded Joints. 87-100 (1994)

[文献書誌] Fumimaru KAWABATA: "Morphological Effect of Local Hard Zones on Fracture Toughness of Weld HAZ" Proceedings of the 2nd Workshop on Constraint Effect on the Structural Performance of Welded Joints. 126-133 (1994)

[文献書誌] Fumiyoshi MINAMI: "Probabilistic Approach to Link Between Design Concept and Toughness Requirement by The Local Approach" Proceedings of the 2nd Workshop on Constraint Effect on the Structural Performance of Welded Joints. 142-146 (1994)

[文献書誌] Masao TOYODA: "Plastic Constraint Controlling Factors and Their Effect" Proceedings of the 2nd Workshop on Constraint Effect on the Structural Performance of Welded Joints. 147-159 (1994)

[文献書誌] Mons HAUGE: "Estimation Lower Bound CTOD Fracture Toughness of HAZ Notched Welds with Mechanical Mismatch" Proceedings of the 10th European Conference on Fracture,ECF10-Structural Integrity,Experiments,and Applications,. 1037-1049 (1994)

[文献書誌] Christian THAULOW: "Effect of Notch Tip Location in CTOD Testing of the Heat Affected Zone of Steel Weldments" Proceedings of the 10th European Conference on Fracture,ECF10-Structural Integrity,Experiments,and Applications,. 1053-1066 (1994)

[文献書誌] 南二三吉: "強度ミスマッチの影響を考慮した鋼多層溶接熱影響部の破壊靭性評価" 溶接学会論文集. 第12巻. 568-574 (1994)

1994 年度実績報告書

豊田政男大阪大学, 工学部, 教授 (00029191)