航空发动机用TWIP钢电化学充氢曲线的模拟研究

Simulation Study of Electrochemical Hydrogen Charging Curve of TWIP Steel for Aero Engine

航空发动机用钢具有良好的力学性能、优良的抗冲击能力和成形性,在先进高强钢中,TWIP钢是较好的选择。但TWIP钢易于发生氢脆,对其生产应用造成很大的技术瓶颈。针对TWIP钢的氢脆问题,本文对航空发动机用TWIP钢进行电化学充氢,研究了电化学充氢过程中溶液成分对充氢的影响,充氢后氢在材料中分布和扩散和充氢时间对氢含量的影响。结果表明:原子氢在钢中的扩散服从菲克定律。测定了可逆转氢含量和不可逆转氢含量,220℃左右出现的峰值表示可扩散氢原子,这些氢原子主要集中在能量较低的氢陷阱中,如位错,晶界。在600℃左右出现的峰值表示不可扩散氢原子,这些氢原子陷阱主要包括碳化物,氮化物,孪晶界等。

Aero engine steel has good mechanical properties,excellent impact resistance and formability.In advanced high strength steel,TWIP steel is a good choice for engine steel usage.However,hydrogen embrittlement is easy to occur in TWIP steel,which leads to a great technical bottleneck for its production and application.Aiming at the hydrogen embrittlement problem of TWIP steel,electrochemical hydrogen charging of TWIP steel for aero-engine is studied in this paper.The influence of solution composition on hydrogen charging during electrochemical hydrogen charging process is studied,and the effect of hydrogen distribution and diffusion in hydrogen and hydrogen charging time on hydrogen content is studied.The results show that the diffusion of hydrogen in steel obeys Fick's law.The content of reversible hydrogen and the content of irreversible hydrogen were measured.The peak at 220℃indicates diffusible hydrogen atoms.These hydrogen atoms are mainly concentrated in low energy hydrogen traps,such as dislocation and grain boundary.The peaks at about 600℃indicate that the hydrogen atoms can not be diffused.These hydrogen atom traps mainly include carbides,nitrides,and twinning boundaries.