Microstructural Evolution and Mechanical Properties of Nb-Ti Microalloyed Pipeline Steel  

作　　者：LAN Liang-yun QIU Chun-lin ZHAO De-wen GAO Xiu-hua 

机构地区：[1]State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110004, Liaoning, China

出　　处：《Journal of Iron and Steel Research International》2011年第2期57-63,共7页

基　　金：Item Sponsored by National Natural Science Foundation of China (51074052);Fundamental Research Funds for Central Universities of China (N100607001)

摘　　要：The correlation between microstructures and mechanical properties of a Nb-Ti microalloyed pipeline steel was investigated. The results revealed that with decreasing the finish rolling temperature and the cooling stop tern perature, the matrix microstructure was changed from quasi-polygonal ferrite to acicular ferrite, as a result of improvement of both strength and low temperature toughness. By means of electron backscattered diffraction observation, an effective acicular ferrite packet contained several low angle boundaries or subboundaries plates which made important contributions to improvement of strength. It was found that many fine quasi-polygonal ferrite grains with high angle boundaries as the toughening structure were introduced into the acicular ferrite matrix to refine effective grain size and improve the toughness.The correlation between microstructures and mechanical properties of a Nb-Ti microalloyed pipeline steel was investigated. The results revealed that with decreasing the finish rolling temperature and the cooling stop tern perature, the matrix microstructure was changed from quasi-polygonal ferrite to acicular ferrite, as a result of improvement of both strength and low temperature toughness. By means of electron backscattered diffraction observation, an effective acicular ferrite packet contained several low angle boundaries or subboundaries plates which made important contributions to improvement of strength. It was found that many fine quasi-polygonal ferrite grains with high angle boundaries as the toughening structure were introduced into the acicular ferrite matrix to refine effective grain size and improve the toughness.

关 键 词：pipeline steel acicular ferrite mechanical property electron backscattered diffraction 

分 类 号：TF[冶金工程]