摘要
以经不同工艺退火的Qst32-3超低碳钢为研究对象,利用金相显微镜、硬度计等研究扭转变形过程中显微组织和性能的演化,利用扫描电镜对扭转断口进行形貌观察。结果表明,扭转变形可促进不充分静态再结晶进行。这主要与温度升高促进溶质原子扩散,降低再结晶激活能以及促进位错运动,缩短再结晶形核时间等因素有关。与退火不充分的试样相比,再结晶充分的样品经扭转变形后,其断口宏观呈平齐状。微观断口形貌显示,前者扭转后心部孔洞较大,撕裂棱明显,后者断口心部孔洞小而浅,韧窝呈剪切状,且无明显的撕裂棱存在。表明,充分退火后材料具有更优的扭转性能。
Evolution of microstructure and properties of Qst32-3 ultra-low carbon steel annealed with different processes during torsional deformation was investigated with optical microscope and hardness meter. Furthermore,the fracture morphology was analyzed by SEM. The results show that the torsional deformation can promote the incomplete static recrystallization,which is mainly related to the increase of solute atoms diffusion and dislocations movement,as well as the decrease of recrystallization activation energy and nucleation time caused by temperature rising.The main fracture mode of Qst32-3 steel with sufficient recrystallization is flat-shaped and the center holes are small and shallow accompanied by shearing dimples with no typical tearing ridges. In contrast,those with incomplete annealing microstructure reveal deeper center holes and more obvious tearing ridges. In summary,materials with fully annealed microstructure can obtain better torsional performance.
出处
《金属热处理》
CAS
CSCD
北大核心
2017年第2期76-79,共4页
Heat Treatment of Metals
关键词
Qst32-3超低碳钢
显微组织
扭转性能
静态再结晶
Qst32-3 ultra-low carbon steel
microstructure
torsional property
static recrystallization
