退火工艺对低碳钢强力旋压变形组织及力学性能的影响

Influence of annealing process on microstructure and mechanical properties of spun workpiece obtained by power stagger spinning

退火温度和退火时间是影响低碳钢旋压件再结晶退火后微观组织及力学性能的主要因素。对不同减薄率的旋压件采取变温恒时和恒温变时的方法,研究退火温度及退火时间对20钢经强力错距旋压后的变形组织及力学性能的影响。试验结果表明,在560℃～600℃区间,旋压件硬度随退火温度的升高急剧减小,退火时间对试样力学性能的影响随退火温度的升高变得更明显;在580℃时保温1h退火后,铁素体均转变成等轴状细晶,晶粒尺寸约0.6μm,尺寸更细小的渗碳体颗粒大部分弥散在铁素体晶界上。

Both the annealing temperature and soaking time are the main factors affecting the microstructure and the mechanical properties of the spun workpiece .The two different methods of varied time vs .constant temperature and varied temperature vs . constant time were adopted to discuss the relationships between the annealing temperature and the microstructure , the mechanical properties of spun workpiece under different reductions of wall thickness obtained by power stagger spinning . The result shows that the workpiece hardness decreased sharply when the annealing temperature rose from 560℃ to 600℃ ,and the influence of the soaking time on the mechanical properties of the spun workpieces becomes more obvious under a higher annealing temperature . After the heating at 580℃ for 1 hour heat soaking , the equiaxed ultrafine grains with average size of approximately 0.6 um were generated ,and the more finer cementite particles were majorly dispersed at the ferrite grain boundaries .