|
|
|
| Composition Optimization of 50mm-Thickness High Strength Low Alloy Steel Q550D |
| YANG Jun,XIAO Qiang-jian,LI Yu-lu,WANG Xiao-jun,ZHANG Qing-xue,YANG Yun-qing |
| Hunan Valin Xiangtan Iron and Steel Company Limited, Xiangtan 411101, Hunan, China |
|
|
|
|
Abstract In order to solve the problem of poor stability of low temperature impact toughness in 50 mm thickness high strength low alloy steel Q550D, the industrial tests were carried out to adjust the alloy compositions. The results show that the strength of steel plates is stable and the elongation is good, the longitudinal impact values at -20℃ are stabilized between 239-324J in quarter thickness and in particular, the first qualification rate of impact toughness of the steels with new compositions can reach 100%, and the microstructure of finished product is improved obviously, and also the cost of unit steel drops much. The industrial tests also show that the elements of precipitation strengthening and solution strengthening in high strength low alloy steel should be added properly according to the smelting condition of molten steel and rolling technology. At the same time, the larger debate on the influence of hardenability on lower temperature impact instability of this steel has been clarified by means of jominy tests, and the tests show that the hardenability of original compositions is superior to that new compositions, that is to say, the poor stability of low temperature impact values of steel plates with original compositions is not due to its poor hardenability, but to its unreasonable compositional desigin is.
|
|
Received: 30 September 2011
Published: 14 January 2013
|
|
|
|
| [1] |
CAO Yan-guang, LI Zhao-dong, DING Can-can, ZHANG Jin-wen, YONG Qi-long, GAO Jian-bing. Effect of niobium addition on hardenability of high-speed railway axle steel[J]. Iron and Steel, 2020, 55(6): 107-112. |
| [2] |
CHEN Ya-jun1,KUANG Shuang2,ZHAO Zheng-zhi3. Study status of hydrogen induced delayed fracture of advanced high strength automotive steel[J]. JOURNAL OF IRON AND STEEL RESEARCH , 2020, 32(4): 265-272. |
| [3] |
TIAN Yan1,2,ZHAO Ming-chun2. Segregation of Nb and its formation mechanism of high strength casing steel[J]. JOURNAL OF IRON AND STEEL RESEARCH , 2020, 32(4): 335-343. |
| [4] |
TIAN Yan1,2,ZHAO Ming-chun2. Segregation of Nb and its formation mechanism of high strength casing steel[J]. JOURNAL OF IRON AND STEEL RESEARCH , 2020, 32(4): 344-350. |
| [5] |
ZHANG Hua-wei，QIN Xiang-dou，LI Jian-bin. Effect of grain size on quenching structure of 40Cr steel[J]. PHYSICS EXAMINATION AND TESTING, 2020, 38(2): 5-. |
| [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. |
|
|
|
|
2012, Vol. 47 
