高張力鋼厚板溶接部のルート割れ試験結果

• 木原 博

  東京大学工学部

• 稲垣 道夫

  金属材料技術研究所

• 鈴木 春義

  八幡製鉄K.K.

• 松永 和介

  川崎重工業K.K.

• 中村 治方

  金属材料技術研究所

書誌事項

タイトル別名

• Root Cracking Test of High Strength Steel Welds with Thick Plates
• A Study of Root Cracking in High Strength Steel Welds (Report II)
• 高張力鋼溶接部のルート割れに関する研究(第3報)

抄録

A series of root cracking tests were conducted with y-groove restraint cracking specimen of high strength steels with thickness from 30 to 50 mm. Effects of size of specimen, including bead length and plate thickness, and of multi-layer weld on root cracking were mainly studied in the report.<BR>The conclusions obtained in the study are as follows:<BR>(1) The root cracking tendencies of six high strength steels with their strength levels from 60 to 79 kg/mm², that is, HT 60 and HT 70 steels, were evaluated and preheating temperatures necessary for the prevention of root cracking were decided.<BR>The maximum hardnesses in HAZ of these steels, which were safe to root cracking, ranged from 350 to 400 VHN under the load of 1 kg.<BR>Microstructures of HAZ safe to root cracking were decided with an, aid of of CCT diagrams, that is, 5-10% ferrite, 20-30% intermediate structure and 60-70% martensite for HT 60 and 10-25% intermediate structure and 75-90% martensite for HT 70 in their area percentages of constituents.<BR>(2) Neither the root crack, which was initiated at the first layer weld, was propagated nor a new crack was initiated with the progress of a multi-layer weld.<BR>Cracking tendencies rather decreased in multi-layer welds with a choice of proper interpass temperature.<BR>(3) An increase of root cracking was not detected with an increase of bead length and a root crack rather increased with a decrease of bead length at a bead length below 150 mm, because of a rapid cooling of a short bead.<BR>Therefore it was suggested that the transverse tensile residual stress in a weld would directly affect the initiation of a root crack and the longitudinal tensile residual stress would indirectly affect the initiation of a root crack.<BR>(4) The tendencies of root cracking did not increase with an increase of plate thickness if the welds were cooled by the same cooling process.<BR>(5) It was confirmed that the slotted cracking specimen with a size of 200 mm×150 mm was equivalent to one of 300×200 mm. The smaller size is therefore satisfactory for a root cracking test of high strength steel welds.

収録刊行物

• 溶接学会誌

  溶接学会誌 33 (3), 182-190, 1964

  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: 1390282681479589760
• NII論文ID: 130003762929
• DOI: 10.2207/qjjws1943.33.182
• 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