Effect of Grain Boundary on Microcracking of Austenitic stainless steel multi-pass weldments
Project/Area Number |
02650528
|
Research Category |
Grant-in-Aid for General Scientific Research (C)
|
Allocation Type | Single-year Grants |
Research Field |
溶接工学
|
Research Institution | Nagoya Institute of Technology |
Principal Investigator |
SAEKI Yoshitaka Nagoya Inst. Tech., Faculty of Engineering, Associate Professor, 工学部, 助教授 (00110255)
|
Project Period (FY) |
1990 – 1991
|
Project Status |
Completed (Fiscal Year 1991)
|
Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1991: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1990: ¥1,500,000 (Direct Cost: ¥1,500,000)
|
Keywords | Stainless Steel / Multi-pass Weld / Microcracking / Segregation / Grain Boundary / Coincidence Site Lattice / 多層溶接部 |
Research Abstract |
In multi-pass weldments of austenitic metallic materials, microcracking is frequently observed. In this study, to clarify mechanism of microcracking occurring in austenitic stainless steel multilayer weldments, relation between microcracking and welding conditions were investigated. And also effect of relation between misorientation and structure of grain boundary in 1st layer of weldments on micro-cracking was studied. Microcracking occur along grain boundaries in the region of 1st layer which locate vicinity of 2nd layer of the welds. As microstructure of weldment is fully austenitic, cracking is very enhanced, and lower welding speed of 2nd layer increase microcracking tendency in 1st layer of weldments. Judging from the observations of fracture surface of microcrack by SEM, cracking occur due to liquation and ductility-dip of grain boundaries. In general, pronounced microcracking tendency in 1st layer of weldments due to following run is observed at grain boundary having large misorientation. It seemthat more segregation of impurity elements, such as S and P, occur at grain boundary having large misorientation cause microcracking. Nevertheless, the segregation at grain boundary observed by CMA and EPMA methods could not be found. It may be concluded that segregational grain boundary could not detect by reason of its narrow width.
|
Report
(3 results)
Research Products
(6 results)