An automobile undercarriage part of the present invention has a welded joint formed by base steel plate,wherein the chemical composition of a weld metal contains, with respect to a total mass of the weld metal, by mass %, C: 0.02% to 0.30%, Si: 0.10% to less than 1.0%, Mn: 1.2% to 3.0%, Al: 0.002% to 0.30%, Ti: 0.005% to 0.30%, P: more than 0% to 0.015%, and S: more than 0% to 0.030%, the following formula (1A), formula (1B), formula (2), and formula (3) are satisfied, and slag in a toe portion of the fillet weld satisfies a formula (4).[Al]+[Ti]>0.05 Formula (1A)[Ti]/[Al]>0.9 Formula(1B)7×[Si]+7×[Mn]−112×[Ti]−30×[Al]≤12 Formula (2)2.0<[Si]+[Mn] Formula (3)[Ti content on slag surface]>[Si content on slag surface] Formula (4).
Automobile undercarriage part
2025-01-28
Patent
Electronic Resource
English