Measurement of Paint Bake Hardening of Metals Conforming to JIS G 3135 Annex A

Materials with high dent resistance are required in automotive outer panels such as doors and hoods. Increasing yield strength is effective for enhancing dent resistance, but forming defects increase during press forming. In order to improve formability, soft materials with low yield strength are required. BH (bake hardening) steel sheets are used to satisfy the mutually contradictory requirements of high formability and high dent resistance. BH steel sheets are soft and have high formability during forming, and are hardened by drying with heat in the subsequent painting process. This article introduces an example of a test conforming to JIS G 3135.