车用退火态Fe-24Mn-4Cr-0.5C高锰钢力学性能和氢脆性能分析

选择在线充氢的方法测试了Fe-24Mn-4Cr-0.5C高锰钢的力学特性,并对其处于不同变形程度下的显微组织形貌进行了观察,分析了钢材试样的力学特性及其氢脆敏感性。研究结果表明:高锰钢的退火组织由呈现等轴分布的单相奥氏体组成,退火温度上升,形成的晶粒尺寸也更小。退火态高锰钢试样发生了连续屈服并表现出强塑积特性,当退火温度上升后,试样的强度也发生了减小。相比较未充氢试样,充氢后的高锰钢的组织均匀性得到了明显提升,试样的强度与塑性显著降低。经过900℃退火后,试样的强塑积达到了最大,而在充氢状态下对试样进行低应变拉伸测试,其强塑积发生了明显减小。当退火温度上升后,高锰钢将更易受到氢脆的影响。

Analysis on mechanical and hydrogen embrittleness properties of annealled Fe-24Mn-4Cr-0.5C high manganese steel for vehicle

The mechanical characteristics of Fe-24 Mn-4 Cr-0.5 C high manganese steel were measured by using the method of on-line hydrogen charging,the microstructure morphologies of Fe-24 Mn-4 Cr-0.5 C high-manganese steel were observed under the different deformation degrees,and the mechanical characteristics and hydrogen embrittleness sensitivity of the steel samples were analyzed.The results show that the annealed microstructure of high manganese steel is composed of single-phase austenite with equiaxial distribution,and the grain size is lower when the annealing temperature rises.The annealed high manganese steel samples show continuous yield and strong plasticization characteristics,and the strength of the samples decreases when the annealing temperature rises.Compared with the non-hydrogen sample,the uniformity of the tissue for high manganese steel after hydrogen charging is significantly improved,and the strength and plasticity of sample decrease significantly.The samples obtained after 900℃annealing reach the maximum strong plasticization,while the slow strain rate testing test of the samples in the hydrogen state significantly reduce the strong plasticization.When the annealing temperature increases,the high manganese steel will be more susceptible to hydrogen embrittlement.