Mn含量对中锰钢微观组织及力学性能的影响

Effect of Manganese Content on Microstructure and Mechanical Properties of Manganese Steel

通过金相观察、X射线衍射、透射分析及力学性能测试,探索了Mn含量对中锰钢微观组织及力学性能的影响。结果表明,通过临界区退火处理,不同锰含量的中锰钢(w(Mn):3.86%~5.4%)在室温下均可获得铁素体和奥氏体复相组织,奥氏体含量随Mn含量的增加而增多,而其稳定性呈相反的变化趋势。试验钢强度随Mn含量的增加而增加,断后伸长率及断面收缩率两塑性指标随Mn含量变化呈相反的变化趋势,冲击韧性随Mn的增加而降低。试验钢力学性能随Mn含量的变化与试验钢中Mn的存在形式、逆转奥氏体的含量及稳定性相关。

The effect of Mn content on microstructure and mechanical properties of medium manganese steel is investigated via metallographic observation,X-ray diffraction,transmission analysis andmechanical testing.The results show that,after intercritical annealing,medium manganese steels with different Mn contents(3.86%~5.40%)all contain the mixedmicrostructure of ferrite and austenite at room temperature.The content of austenite in the treated steel increases with the increase of Mn content,while the stability shows an opposite trend.With the increase of Mn content,The strength of the tested steel increases,while the percentage elongation after fracture and percentage reduction of area and the impact toughness of thetested steels decrease.The variation of mechanical properties of the tested steel with the Mn content is related to the existingform of Mn and the content and stability of reverse austenite.