通过Gleeble-2000试验机研究了Q345C钢连铸坯的高温热塑性。利用扫描电镜、金相显微镜、透射电镜观察了第Ⅰ、Ⅲ脆性温度区内拉伸试样断口部位的显微组织及形貌,分析了动态再结晶、相变、析出物等对微合金化钢高温延塑性的影响。结果表明：在1×10-3/s应变速率下,Q345C钢存在两个脆性温度区,即第Ⅰ脆性区（1 200～1 300℃）和第Ⅲ脆性区（600～875℃）,无第Ⅱ脆性区出现;最高塑性出现在1 050℃左右,断面收缩率（Z）达到85.8%;在第Ⅲ脆性区,沿奥氏体晶界析出膜状铁素体抗拉能力较低,晶界处存在夹杂物以及微合金元素的析出物,是钢的热塑性降低的主要原因。
Hot ductility of continuous casting Q345C slabs was tested by Gleeble-2000 thermal/strain simulation ma- chine. Using scanning electron microscopy, metalloscopy and transmission electron microscopy, morphology eharac teristics and microstructure of fracture surface of tensile specimen in Brittle temperature zone Ⅰ and Ⅲ were ob served. Influences of dynamic recrystallization, phase change and precipitate on hot ductility of the niobium- micro-alloyed steel were analyzed. The results showed that： at the 1× 10^-3/s strain rate, there are two low ductility zones, namely brittle zone i （1200 1300℃） and brittle zone Ⅲ（600 875 ℃） ,the brittle zone Ⅱ does not exist; the maximum ductility is around 1 050 ℃ and area reduction （Z）reached 85.80/00; in brittle zone Ⅲ , membranous lower tensile strength of ferrite along austenite grain boundaries, and the existence of inclusions and precipitates of micro- alloying elements in the grain boundaries is the main reasons for lower ductility of Q345C steel.
参考文献
| [1] | 陈登福,高兴健,王启明,王水根,宋立伟.Q235G钢连铸坯的高温力学性能分析[J].过程工程学报,2009(z1):210-213. |
| [2] | Hori S;Suzuki M;Unigame Y .Effect of Carbon on the Low Temperature Brittleness of Iron[J].Journal of the Japan In- stitute of Metal,1980,44(02):138. |
| [3] | 孙彦辉,倪有金,许中波,蔡开科.中碳钢高温力学和冶金行为[J].北京科技大学学报,2009(06):708-713. |
| [4] | B Mintz;R Abushosha;M Shaker .Influence of Deformation- Induced Ferrite, Grain-Boundary Sliding, and Dynamic Re- crystallisation on Hot Ductility of 0. 1-0. 75% C Steels[J].Materials Science and Technology,1993,9(10):907. |
| [5] | 吴光亮,孙彦辉,周春泉,蔡开科,李正邦.CSP板坯（Q235B）高温力学性能试验研究[J].钢铁,2006(05):73-77. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%