收费全文 | 241篇 |
免费 | 0篇 |
电工技术 | 3篇 |
综合类 | 3篇 |
化学工业 | 42篇 |
金属工艺 | 49篇 |
机械仪表 | 18篇 |
建筑科学 | 1篇 |
矿业工程 | 1篇 |
能源动力 | 2篇 |
石油天然气 | 9篇 |
无线电 | 2篇 |
一般工业技术 | 68篇 |
冶金工业 | 30篇 |
原子能技术 | 10篇 |
自动化技术 | 3篇 |
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 4篇 |
2019年 | 5篇 |
2018年 | 7篇 |
2017年 | 11篇 |
2016年 | 7篇 |
2015年 | 4篇 |
2014年 | 9篇 |
2013年 | 14篇 |
2012年 | 8篇 |
2011年 | 9篇 |
2010年 | 9篇 |
2009年 | 14篇 |
2008年 | 6篇 |
2007年 | 7篇 |
2006年 | 4篇 |
2005年 | 4篇 |
2004年 | 5篇 |
2003年 | 7篇 |
2002年 | 7篇 |
2001年 | 5篇 |
2000年 | 4篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1990年 | 3篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 6篇 |
1973年 | 5篇 |
1972年 | 2篇 |
1971年 | 3篇 |
1970年 | 1篇 |
1969年 | 3篇 |
1968年 | 6篇 |
1965年 | 2篇 |
1964年 | 1篇 |
1963年 | 3篇 |
1962年 | 2篇 |
1961年 | 5篇 |
1960年 | 1篇 |
1959年 | 1篇 |
1956年 | 1篇 |
-
The vE value of the weld metal core is lower than that of the weld metal rim. The absorbed energy transition temperature is also higher.
-
The vE values of the weld metal core and rim altered with a change in the welding heat input Q (varied at six levels in the 10.1 ~ 126.7 kJ/mm range), generally decreasing with an increasing heat input. The vE value of the core is lower than that of the rim. In the weld metal produced at the maximum heat input (126.7 kJ/mm), however, the core and rim have much the same vE values.
-
The vE value of the weld metal core shows little change with a change in the steel type (one type of TMCP and two types of SM490A), and remains at a low value. When there is a change in the surrounding gas (oxygen (O2), air, and argon gas), the vE value decreases in an Ar, air, O2 sequence.
-
The weld metal core vE value is little dependent on any change in the flux type (three types of fused flux) and weight of flux used (0.5 or 0.7 N).
-
The microstructural observations suggest that grain‐boundary ferrite (GBF) occurs at the coarse prior austenite grain boundaries of the rim, with fine acicular ferrite (AF) being mainly found trans‐granularly. In the core, grain‐boundary ferrite is formed at high density at the fine prior austenite grain boundaries, with massive polygonal ferrite (PF) being formed at high density transgranularly. There are thus distinct differences in the coarse ferrite morphology of the rim and core.
-
The SEM observations of the fracture surfaces suggest that the core weld metal has a large grain size, a feature corresponding to its low vE value. The observations made at the fracture surface periphery indicate that numerous secondary cracks are initiated in the grain‐boundary ferrite of the core, suggesting that the ferrite has a low toughness.
-
The results of the SEM simultaneous fractographic‐microstructural observations suggest that fracture selectively propagates along the grain‐boundary ferrite. This indicates that the low vE value of the core is due to the presence of high‐density grain‐boundary ferrite and massive transgranular polygonal ferrite.