METHOD FOR EVALUATING SUSCEPTIBILITY OF STEEL MATERIAL TO HYDROGEN EMBRITTLEMENT

• Main Authors: MANABE TOSHIYUKI, MATSUI NAOKI, SENDA TETSUSHI, HIRAGAMI DAISUKE, KOSAKA MAKOTO
• Format: Patent
• Language: English; Japanese
• Published: 19.01.2022
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

To provide a method for evaluating susceptibility of steel material to hydrogen embrittlement enabling a fracture surface composed mainly of a grain boundary fracture surface to be generated in a test piece and enabling destruction due to hydrogen embrittlement to be simulated within a short period of time.SOLUTION: In a first embodiment, a method for evaluating susceptibility of steel material to hydrogen embrittlement comprises a step of charging hydrogen to a test piece and applying tensile stress to the test piece while a stress concentration portion is generated in the test piece, and a step of controlling an amount of strain of the test piece to a constant value. In a second embodiment, the method further comprise a step of forming an annular stress concentration region having a stress concentration coefficient of more than 1 and less than or equal to 20 in the test piece, and when tensile stress is applied to the test piece, an angle formed by an axis center of a support unit at both ends of the test piece may be greater than or equal to 0° and less than or equal to 3°.SELECTED DRAWING: Figure 7A 【課題】主に粒界破面から構成される破断面を試験片に生じさせることが可能であり、水素脆化による破壊を短期間のうちに模擬可能である、鋼材の水素脆化感受性の評価方法を提供する。【解決手段】本発明の一態様に係る鋼材の水素脆化感受性の評価方法は、試験片に水素をチャージし、且つ、前記試験片に応力集中部を生じさせた状態で、前記試験片に引張応力を加える工程と、前記試験片のひずみ量を一定値に制御する工程と、を備える。前記試験片に引張応力を加える前に、前記試験片に、応力集中係数が１超２０以下である環状の応力集中領域を形成する工程をさらに備え、前記試験片に引張応力を加えるときに、前記試験片の両端における支持部の軸芯がなす角度を０°超３°以下としてもよい。【選択図】図７Ａ