Recent studies suggested that nanotwinned metallic materials can exhibit a good combination of high strength and high ductility. However, few studies examined the strength and ductility of nanotwinned alloys under hydrogen atmosphere. In this study, nanotwins are introduced in a TWIP (twinning-induced plasticity) steel by application of high-pressure torsion (HPT) followed by annealing. The nanotwinned austenitic TWIP steel exhibited a high tensile strength as ∼1.4 GPa but without ductility after hydrogen charging. Unlike nanotwinned alloy, the HPT-processed sample, which experienced a phase transformation to a bimodal martensitic structure, exhibited both high strength (∼1.6 GPa) and high uniform ductility (6%) after hydrogen charging. It was concluded that twin boundaries act mainly as crack initiation sites and propagation paths but not as effective barriers for dislocation accumulation to enhance the ductility of the TWIP steels under hydrogen atmosphere.

最近的研究表明，纳米孪晶金属材料可以表现出高强度和高延展性的良好组合。但是，很少有研究检查在氢气氛下纳米孪晶合金的强度和延展性。在这项研究中，通过施加高压扭力（HPT），然后进行退火，将纳米孪晶引入TWIP（孪生诱导可塑性）钢中。纳米孪晶奥氏体TWIP钢显示出约1.4 GPa的高拉伸强度，但在充氢后没有延展性。与纳米孪晶合金不同，经HPT处理的样品经历了相转变为双峰马氏体结构，在充氢后既显示出高强度（〜1.6 GPa）又显示出高均匀延展性（6％）。