|
|
|
| Microstructure and mechanical properties of low carbon copper- containing steel plate for shipbuilding with yield strength of 785 MPa |
| CHENG Bing- gui,WU Feng- juan,LIU Dong- sheng |
| Institute of Research of Iron and Steel of Jiangsu Province（Shasteel），Zhangjiagang215625,Jiangsu，China |
|
|
|
|
Abstract The continuous cooling transformation (CCT) behavior of an advanced steel used as offshore structure and shipbuilding with yield strength greater than 785 MPa was studied. A novel process route consisting of controlled- rolling and direct quenching followed by tempering (DQ- T) was used to process the tested steel. The microstructure and mechanical properties of DQ- T treated plates were studied. The as- quenched plate consists of refined lathlike martensite (LM) with high- density dislocations，which act as preferred precipitation sites for ε- Cu and/or NbC particles during tempering. These precipitates improve the tempering resistance of the steel. Peak strength associated with the lowest impact toughness is achieved in the steel tempered at 500 ℃. The microstructure of the plate tempered at 710 ℃ (in two- phase region) for 1 h consists of secondary lathlike martensite (SLM) and ferrite ，resulting in best combination of strength and toughness，i. e. ，yield strength (Re) of 810 MPa，ultimate tensile strength (Rm) of 1 066 MPa，Charpy V- notch toughness(KV2)of 97 J even at- 80 ℃.
|
|
Received: 05 December 2014
Published: 18 August 2015
|
|
|
|
| [1] |
CAO Jing-hua1,PAN Hong-bo2,3,ZHANG Jing1,ZHANG Teng-fei2,LI Xu-dong2,LIU Wei-ming2,3. Continuous cooling transformation of NbTi microcarbon deep drawing dualphase steel[J]. JOURNAL OF IRON AND STEEL RESEARCH , 2020, 32(4): 322-328. |
| [2] |
YANG Geng-wei1,HU Zhuo-li1,YIN Qi-long1,MAO Xin-ping1,2,MIAO Li-sha1,LIU Yang2. Effect of phase transformation time on microstructure and mechanical properties of hotrolled TRIP steel produced by CSP process[J]. JOURNAL OF IRON AND STEEL RESEARCH , 2020, 32(2): 143-149. |
| [3] |
FENG Lu-lu1,2,3,WU Kai-ming1,LI Ping-ping2,CHEN Shu-min2,LU Xiu-yu4,QIAO Wen-wei3. Effect of Nb on microstructure transformation in reheating process of 2000MPa bridge cable steel[J]. JOURNAL OF IRON AND STEEL RESEARCH , 2020, 32(1): 60-65. |
| [4] |
ZHAI Zhan-jiang1,2,CAO Yang1, 3,ZHAO Lin1,PENG Yun1,TIAN Zhi-ling1,ZHU Jiao4. Effect of heat input on microstructure and mechanical properties of DP980 laser welded steel[J]. JOURNAL OF IRON AND STEEL RESEARCH , 2020, 32(1): 66-73. |
| [5] |
WANG Yunan，JIANG Xiaofang. Investigation on inclusions and microstructure of #br#
offshore steel for high heat input welding[J]. Iron and Steel, 2019, 54(8): 209-215. |
| [6] |
YANG Geng-wei,LU Jia-wei,SUN Hui,FANG Zi-wei,ZHOU Yi-liao,YAO Nan. Microstructure, mechanical properties and phase transformation behavior of TiV microalloyed highstrength hotstrip steel[J]. JOURNAL OF IRON AND STEEL RESEARCH , 2019, 31(8): 726-732. |
|
|
|
|
2015, Vol. 50 
