Microstructure and Mechanical Behavior of Induction-Assisted Laser Welded AHS Steels

Autor(es)

Lima, M. S. F. ^[1] ; Gonzales, D. ^[2] ; Liu, S. ^[2]

Afiliação do(s) autor(es)

^[1] Inst Adv Studies, Sao Paulo - Brazil

^[2] Colorado Sch Mines, Golden, CO 80401 - USA

• Tipo de documento: Artigo Científico
• Fonte: WELDING JOURNAL; v. 96, n. 10, p. 376S-388S, OCT 2017.
• Citações Web of Science: 1

Resumo

The present study proposes an innovative method of laser welding at high temperatures, where the rapid solidification and preheating were performed consecutively in the same setup. The 22MnB5 hot pressed, advanced high-strength steel (AHSS) parts were heated to a given temperature and held for a given time to ensure an isothermal condition, after which, laser welding was performed. The welded part was then maintained at a high temperature for a sufficient time to develop a bainitic structure. A steel part was welded both in ambient and high-temperature conditions. The welds made using the same laser parameters, an induction heating to 445 degrees or 529 degrees C, and isothermal treatment of 10 min produced a bainite plus retained austenite microstructure. The hardness was greatly reduced when using the high-temperature welding method, and the hardness profiles were flat compared to the room temperature welded sample. The tensile behavior of the room temperature welded coupons presents high tensile strength (1200 MPa) and negligible maximum elongation (1.3%). Alternatively, the high-temperature coupons present tensile strengths of 840 and 650 MPa and total elongation of 2.7 and 3.5%, for the conditions 445 degrees and 529 degrees C, respectively. Therefore, the high temperature coupons demonstrated higher toughness compared to the room temperature coupons. (AU)

• Processo FAPESP: 14/26930-7 - Soldagem a laser de aços avançados de alta resistência mecânica no campo bainítico para aplicações aeroespaciais
• Beneficiário: Milton Sergio Fernandes de Lima
• Modalidade de apoio: Bolsas no Exterior - Pesquisa