Simplified Evaluation of Brittle Crack Arrest Toughness in Heavy-thick Plate by Combined Small-scale Tests

2017 ◽  
Vol 27 (2) ◽  
pp. 210-215 ◽  
Author(s):  
Teppei Okawa ◽  
Hiroyuki Shirahata ◽  
Kiyotaka Nakashima ◽  
Kazuhisa Yanagita ◽  
Takehiro Inoue
Keyword(s):  
Thick Plate ◽  
Crack Arrest ◽  
Small Scale ◽  
Brittle Crack ◽  
Arrest Toughness

Study on Unstable Brittle Crack Arrest Toughness of Extremely-Low Carbon Bainitic Steel Plates

Materials ◽  
2004 ◽  
Author(s):  
Tsunehisa Handa ◽  
Takahiro Kubo ◽  
Keniti Amano ◽  
Mitsuhiro Okatsu ◽  
Kazunori Miyamoto ◽  
...  
Keyword(s):  
Transition Temperature ◽  
Cross Section ◽  
Test Piece ◽  
Main Crack ◽  
Crack Arrest ◽  
Steel Plates ◽  
Bainitic Steel ◽  
Low Carbon ◽  
Brittle Crack ◽  
Arrest Toughness

The extremely-low carbon bainitic steel (ELCB steel) is a high strength steel with about 0.02 mass% or less carbon. In this research, unstable brittle crack arrest toughness of ELCB steel plates was investigated by temperature-gradient ESSO tests, compared with that of conventional TMCP steel plates. Both of ELCB and TMCP steel plates without pre-straining had sufficient crack-arrest toughness at 0°C. After 10% prestraining, the TMCP steel plate had not sufficient crack-arrest toughness at 0 °C . The ELCB steel plates, however, maintained high crack arrest toughness at 0°C. even after 10% pre-straining. ELCB steel were also different from TMCP steels in the correlation between transition temperature of crack arrest toughness and fracture appearance transition temperature (vTrs) obtained by Charpy impact test. When the vTrs of an ELCB steel and that of a TMCP steel were the same value, crack arrest toughness of an ELCB steel was higher than that of a TMCP steel. In the cross section of the ESSO test piece of the ELCB steels, many sub-cracks and micro-crack branching were observed. However, in the cross section of the ESSO test piece of the conventional TMCP steels, there were few subcracks and branching. Initiation of sub-cracks and branching around the main crack tip reduces the stress intensity factor of the main crack. It was considered that the above features of the ELCB steel were caused by initiation of sub-cracks and branching at the tip of the main brittle crack.

scholarly journals Mechanism of Brittle Crack Arrest Toughness Improvement Due to Texture

2012 ◽  
Vol 98 (10) ◽  
pp. 548-557 ◽  
Author(s):  
Tsunehisa Handa ◽  
Satoshi Igi ◽  
Shigeru Endo ◽  
Seishi Tsuyama ◽  
Tetsuya Tagawa ◽  
...  
Keyword(s):  
Crack Arrest ◽  
Brittle Crack ◽  
Arrest Toughness ◽  
Toughness Improvement

Brittle Crack Propagation/Arrest Behavior in T-Joint Structure of Heavy Gauge Steel Plates

2012 ◽  
Vol 706-709 ◽  
pp. 914-919 ◽  
Author(s):  
Tsunehisa Handa ◽  
Kimihiro Nishimura ◽  
Hiroshi Shiomi ◽  
Seishi Tsuyama
Keyword(s):  
Crack Propagation ◽  
Steel Plate ◽  
Crack Arrest ◽  
Steel Plates ◽  
Brittle Crack ◽  
K Value ◽  
Joint Structure ◽  
Large Heat ◽  
Large Container ◽  
Arrest Toughness

Brittle crack arrestability is extremely important in welded joints of heavy gauge steel plates used in large container ships. Recently, much attention has been focused on potential crack propagation along welds using large heat input. This paper examines the application of a T-joint to the strength deck structure of container ships to enhance crack arrestability. The crack arrest toughness, Kca, for crack arrest was varied. The ESSO test of T-joint components showed that brittle crack was arrested at the T-joint if the steel plate used for the flange had a high Kca value in the range from 4900 to 7300N/mm3/2. FE-analysis of the stress intensity factor K indicated that brittle crack propagation was arrested under the condition that the K-value at the running crack tip was less than the Kca of the material. In the T-joint, it was noted that the K-value around the area of the deepest point of the crack decreased and was finally less than the Kca of the flange plate when the brittle crack penetrated suddenly into the flange plate to a 10mm depth. This phenomenon shows the advantage of using a T-joint for brittle crack arrest in the flange plates of strength deck structures.

scholarly journals Unstable Brittle Crack-Arrest Toughness of Newly Developed Steel Plate with Surface Layers having Ultra Fine Grain Microstructure (2)

1995 ◽  
Vol 1995 (178) ◽  
pp. 555-563 ◽  
Author(s):  
Tadashi Ishikawa ◽  
Takehiro Inoue ◽  
Yukito Hagiwara ◽  
Shigeru Ohshita ◽  
Takao Kuroiwa ◽  
...  
Keyword(s):  
Steel Plate ◽  
Crack Arrest ◽  
Brittle Crack ◽  
Surface Layers ◽  
Fine Grain ◽  
Arrest Toughness
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