METHOD, DEVICE, AND PROGRAM FOR PREDICTING DELAYED FRACTURE IN PRESS-FORMED ARTICLE, AND METHOD FOR MANUFACTURING PRESS-FORMED ARTICLE

• Main Authors: MINOTE TORU, ISHIWATARI AKINOBU, TATSUKAWA KOJI
• Format: Patent
• Language: English; Japanese
• Published: 06.10.2023
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; PERFORMING OPERATIONS; PHYSICS; PUNCHING METAL; TESTING; TRANSPORTING; WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS ORPROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL

To provide a method, a device and a program for predicting delayed fracture in a press-formed article which predict a site where delayed fracture occurs in the press-formed article of a high-tensile steel plate, and a method for manufacturing the press-formed article.SOLUTION: A method for predicting delayed fracture in a press-formed article pertaining to the present invention includes: a step (S1) for calculating a stress distribution and a strain distribution of a press-formed article; a step (S5) for setting a hydrogen concentration distribution corresponding to the strain distribution calculated for the press-formed article on the basis of an expression relating strain and hydrogen concentration that is acquired in advance for a high-tensile steel plate; a step (S7) for performing hydrogen diffusion analysis for the press-formed article on the basis of the stress distribution and the hydrogen concentration distribution and calculating a hydrogen concentration distribution after hydrogen diffusion; and a step (S9) for predicting a site of occurrence of delayed fracture in the press-formed article on the basis of a delayed fracture determination condition based on the stress, strain, and hydrogen concentration acquired in advance, and the stress distribution, the strain distribution, and the hydrogen concentration distribution after hydrogen diffusion.SELECTED DRAWING: Figure 1 【課題】高張力鋼板のプレス成形品において遅れ破壊の発生する部位を予測するプレス成形品の遅れ破壊予測方法、装置及びプログラム、並びにプレス成形品の製造方法を提供する。【解決手段】本発明に係るプレス成形品の遅れ破壊予測方法は、プレス成形品の応力分布及びひずみ分布を算出する工程（Ｓ１）と、高張力鋼板について予め取得したひずみと水素濃度の関係式に基づいて、プレス成形品について算出したひずみ分布に対応した水素濃度分布を設定する工程（Ｓ５）と、応力分布と水素濃度分布とに基づいてプレス成形品について水素拡散解析を行い、水素拡散後の水素濃度分布を算出する工程（Ｓ７）と、予め取得した応力、ひずみ及び水素濃度に基づく遅れ破壊判定条件と、応力分布、ひずみ分布及び水素拡散後の水素濃度分布と、に基づいて、プレス成形品における遅れ破壊の発生する部位を予測する工程（Ｓ９）と、を含むものである。【選択図】 図１