オーステナイト系ステンレス鋼ならびにその溶接継手における応力腐食割れ伝ぱ特性の破壊力学的評価に関する研究　ＶＩＩ　　溶接残留応力下における応力腐食割れ伝ぱ挙動とその推定法について

• 向井 喜彦

  大阪大学工学部

• 村田 雅人

  大阪大学工学部

書誌事項

タイトル別名

• An Application of Fracture Mechanics to Stress Corrosion Cracking in Austenitic Stainless Steels and their Welded Joints (Report 7)
• 溶接残留応力下における応力腐食割れ伝播挙動とその推定法について

抄録

Crack propagation features of stress corrosion cracking (SCC) of type 304 stainless steel in 42 % MgCl₂ solution were studied in a ream of our papers and it was made clear that crack growth rate was respresented well using the following equation.<BR> da/dt=C(Ke/2ff-KI/2scc) C:const …………(1)<BR>{da/dt : Crack growth rate<BR>K : Stress intensity factor<BR>K_ISCC : Threshold stress intensity factor in SCC<BR>In the present paper, crack propagation behavior of SCC in residual stress field in welded joints was predicted by the following integrated form of equation (1), as an example of application to nearly practical problem.<BR> t= ∫ da/C(K²-K²_ISCC) …………(2)<BR>K in arbitrary crack length in welded joint was calculated by method of superposition. And the integration mentioned above can be done easily by Simpson's integration with computer. Now, SCC which was occured in actual welded joints would be more complicated, because crack morphology were not always single crack. It's almost analytically impossible to obtain strict solution for K in the case of irregular or branching cracks, so that, above all, evaluation of K in branching crack would be the most important problem to simulate the crack propagation behavior of SCC by means of computer. This problem was settled by defining the maximum mean value of K, K^*_eff, for branching crack as a new simplified quantative analysis method. By this method, a certain safety factor was considered in the step of calculation of K, and that it's useful from the standpoint of design, although the accuracy of solution deceases. ceases.<BR>As the results, when the residual stress distribution in no crack plates has already known, crack propagation behavior of SCC could be predicted by numerical analysis of equation (2). Namely, crack length in arbitraly time and arresting point of crack by decreasing of potential energy in system, or welded joint, could be predicted in the range of practically permissible error.

収録刊行物

• 溶接学会誌

  溶接学会誌 49 (3), 191-197, 1980

  一般社団法人 溶接学会

キーワード

• Metals and Alloys
• Surfaces, Coatings and Films
• Mechanical Engineering
• Mechanics of Materials

詳細情報

• CRID: 1390001206500266880
• NII論文ID: 130003763532
• DOI: 10.2207/qjjws1943.49.191
• ISSN: 18837204
• ISSN: 00214787
• 本文言語コード: ja
• データソース種別:
  • JaLC
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可