本研究是針對超高強度麻時效鋼,施以雷射處理以改善氫脆抵抗能力。時效硬化的試片經雷射表面退火處理後,形成特殊之複合區域,由外圍表面軟化的雷射退火區域及內部硬化母材區所組成。實驗結果顯示:在大氣中,母材有較佳的拉伸性質,但在硫化氫環境中,雷射表面退火試片的強度反而比母材高。另一方面,由於殘留應力作用,雷射退火處理試片在複合區域其疲勞裂縫成長速率均較母材為低,另一方面,材料之氫脆敏感性亦可獲得改善。 This paper shows that laser beam irradiation improves resistance to hydrogen embrittlement (HE) in a T-250 maraging steel. Localized laser irradiation of a peak-aged steel plate resulted in the formation of a soft surface layer called the laser-annealed zone (LAZ). A composite region (CR) was formed when both the top and bottom surfaces of a specimen were laser-annealed (L-A) to leave an interior layer of untransformed base metal (BM) sandwiched between the two LAZs. Slow strain rate tensile (SSRT) tests showed that the soft LAZs showed less susceptibility to HE than the BM. The fatigue crack growth rates (FCGRs) in the CR were lower than those in the BM regardless of testing environment and stress (R) ratio. The retarded crack growth in the CR was attributed to the presence of residual compressive stress in the soft LAZs.