自動車用ダイクエンチ鋼板の微細組織、硬度および磁気ヒステリシス特性に与える焼入効果

抄録

　Hardness and magnetic hysteresis loop measurements were performed in a partially die-quenched (DQ) steel plate, and the small steel pieces of spesimen with different cooling rate. The change in microstructre of the specimens were quantitatively characterised by electron backscattering diffraction (EBSD) measurement. A good correlation between hardness and coercivity was confirmed in both series of specimens, which is related to to the formation of martensite. This study demonstrates the plausibility of magnetic nondestructive evaluation of the hardness in DQ products, which improves the quality assurance of automobile components.