J.B. Liu
,
L.J. Hu
,
Y.T. Wang
,
Z.Q. Liu
,
K. Miao
,
Z.L. Tian
金属学报(英文版)
The transformation behavior and microstructure development in the heat affected zone
(HAZ) of 800MPa grade ultra fine structured steel was investigated. It was found that
the HAZ has intermediate temperature transformation characteristics in a wide range
of cooling rates, with the bainite sheaves consisting of bainite ferrite plates without
carbide precipitation and retained austenite in the fast cooling regime. At relatively
high cooling rates, which corresponded to low heat inputs, the hardness of the simulated
HAZ was above that of the base metal. When the cooling rate was below 9±C/s, the
welding HAZ would have an obvious softening. The analysis of transformation rates
in continuous cooling processes was completed by numerical differential method. The
result indicated that the microstructure transformation rate of the HAZ in 800MPa
grade ultra fine structured steel changed sharply to slow speeds when the cooling time
t8=5 is longer than 7s.
关键词:
ultra fine structured steel
,
null
,
null
,
null
,
null
Z.G. Shang
,
Z.Q. Liu
,
P.J. Shang
,
J.K. Shang
材料科学技术（英文）
TiO2 nanowires were synthesized successfully in a large quantity by thermal evaporation using titanium monoxide powder as precursor. X-ray diffraction results showed that all the products were pure rutile phase of TiO2. According to microstructural observations, the nanowires have two typical morphologies, a long straight type and a short tortuous type. The straight nanowires were obtained at a wide temperature range of 900−1050 °C, while the tortuous ones were formed below 900 °C. Transmission electron microscopy characterization revealed that both the straight and the tortuous nanowires are single-crystal rutile TiO2. The preferential growth direction of the nanowires was determined as [110] orientation according to electron diffraction and high-resolution image analyses. The morphological change of TiO2 nanowires was discussed by considering the different atomic diffusion rates of Ti atoms caused by the phase transformation in Ti substrate at around 900 °C.
关键词:
Rutile-TiO2
,
null
,
null
,
null
,
null
,
null
张强
,
许少普
,
李忠波
,
唐郑磊
,
高照海
,
杨阳
钢铁
doi:10.13228/j.boyuan.issn1001-0963.20150135
采用横截面为350mm×2 320 mm的钢坯轧制横截面为100 mm×2 360 mm的Q345E-Z35.在粗轧阶段以高于动态再结晶临界变形量和形状系数l/h≥0.53的条件下,经过不同的终轧温度和返红温度试验,最终确定精轧阶段终轧温度控制在780℃左右,返红温度控制在610℃左右,生产出的钢板具有优异的力学性能和层状撕裂抗性.
关键词:
Q345E-Z35
,
特厚板
,
控轧控冷
朱书成
钢铁研究学报
采用高倍金相检验、扫描电镜及能谱分析等方法对120mm Q390GJC-Z35特厚板的z向性能不合缺陷进行了研究。结果表明：z向性能不合主要是由于钢锭存在着较严重的中心偏析,在不合试样断口处存在着较多的块状（Nb、Ti）C聚集,块状的（Nb、Ti）C成为裂纹源。此外,偏析处还存在贝氏体等硬相组织,更加剧了断裂扩展,导致z向性能不合。通过优化成分设计,加强精炼过程控制,改进模铸浇注工艺,制定合理热处理工艺等相关措施,取得了良好的效果。
关键词:
Q390GJC-Z35
,
z向性能
,
不合
,
原因分析
,
措施
唐郑磊
,
张涛
,
杨东
,
李红洋
,
徐昭
,
庞林
钢铁研究
通过成分设计、轧制、热处理工艺设计,采用晶粒细化、固溶强化、析出强化等手段,对80、110mm的Q460GJC-Z35高强度钢板的研发工艺及过程进行试验设计。结果表明：通过Nb、V、Ti、Ni复合微合金化和控轧控冷、正火快冷（NAC）热处理相结合生产的模铸Q460GJE-Z35钢板具有晶粒细小、组织均匀,钢板屈服强度达到420~490 MPa,抗拉强度达到585~625 MPa,伸长率达到20%以上,0℃冲击功达到123 J以上,Z向断面收缩率大于35%,探伤达到1级探伤要求,实现了强度和韧性的良好匹配和较高的内部质量。
关键词:
Q460GJC-Z35
,
成分设计
,
热处理工艺设计
唐郑磊
,
张涛
,
杨东
,
李红洋
,
徐昭
,
庞琳
钢铁
在生产试验的条件下,通过成分设计和轧制、热处理工艺设计,采用晶粒细化、固溶强化、析出强化等手段,对80、110、120mm厚的Q460GJE-Z35高强度钢板的研发工艺及过程进行了试验研究。结果表明：通过铌、钒、钛、镍复合微合金化和控轧控冷、正火快冷（NAC）热处理相结合生产的模铸Q460GJE-Z35钢板晶粒细小、组织均匀,强度和韧性匹配良好、内部质量较优。
关键词:
Q460GJE-Z35钢板
,
成分设计
,
正火加速冷却
朱书成
,
于飒
,
高照海
,
李忠波
,
袁永旗
钢铁
利用250mm连铸坯料,在3 800mm宽厚板轧机上针对Q345GJC-Z35钢种进行了厚50～80mm钢板的TMCP工艺试验,确定了相应的热轧及控冷工艺条件。结果表明：采用碳的质量分数低于0.11%添加微量复合铌、钒、钛元素,按照2阶段控制,当轧到成品钢板厚度的2～3倍时开始待温,精轧开轧温度小于860℃,终轧温度为820～860℃,生产的Q345GJC-Z35高强度厚板的性能完全超出国家标准GB19879—2005要求,而且其钢板的平均断面收缩率都大于50%,远高于Z35钢板的技术要求。实现了钢板很好的强韧性匹配,工艺上不用后续热处理,减少了工艺流程,节约了成本。
关键词:
Q345GJC-Z35钢
,
特厚钢板
,
控制轧制
,
Z向性能
