Effect of Microstructure Refinement on the Strength and Toughness of Low Alloy Martensitic Steel |
| |
Authors: | Chunfang WANG Maoqiu WANG Jie SHI Weijun HUI Han DONG |
| |
Affiliation: | National Engineering Research Center of Advanced Steel Technology, Central Iron and Steel Research Institute, Beijing 100081, China |
| |
Abstract: | Martensitic microstructure in quenched and tempered 17CrlMiMo6 steel with the prior austenite grain size ranging from 6 μm to 199 μm has been characterized by optical metallography (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The yield strength and the toughness of the steel with various prior austenite grain sizes were tested and correlated with microstructure characteristics. Results show that both the prior austenite grain size and the martensitic packet size in the 17CrNiMo6 steel follow a Hall-Petch relation with the yield strength. When the prior austenite grain size was refined from 199 μm to 6 μm , the yield strength increased by 235 MPa, while the Charpy U-notch impact energy at 77 K improved more than 8 times, indicating that microstructure refinement is more effective in improving the resistance to cleavage fracture than in increasing the strength. The fracture surfaces implied that the unit crack path for cleavage fracture is identified as being the packet. |
| |
Keywords: | Martensitic steel Grain refinement Strength Impact toughness Cleavage fracture |
本文献已被 维普 万方数据 等数据库收录! |
| 点击此处可从《材料科学技术学报》浏览原始摘要信息 |
|
点击此处可从《材料科学技术学报》下载全文 |
|