Laser surface remelting and hardening of an automotive shaft sing a high-power fiber laser

Materials Research

Milton Sergio Fernandes De Lima²  Flávia Aline Goia²  Rudimar Riva²  Ana Maria Do Espírito Santo¹ 

[1] ,Institute for Advanced StudiesSão José dos Campos SP ,Brazil

关键词: laser surface hardening;    laser remelting;    fiber laser;   

DOI  :  10.1590/S1516-14392007000400022

来源: SciELO

【 摘 要 】

An automotive shaft was surface-remelted and hardened using a 2 kW fiber laser and an adapted linear axis whose rotating axis produced helical tracks at 120 RPM. The process variable was the laser power, ranging from 300 to 1100 W, which produced two regions in the material: a martensitic region (MR) and a partially transformed region (PTR). The MR is formed after rapid solidification or austenitization followed by rapid cooling (10(7) K.s-1). The PTR is composed of martensite, unchanged pearlite and proeutectoid ferrite. The maximum case depth was about 0.3 mm. The microhardness inside the martensitic regions are at least double that of the base material, i.e. between 800 than 600 HV compared to 300 HV. Thermal simulations using a modified Rosenthal formalism help elucidate the phase transformation inside the material and show good agreement with experimental results. The experimental laser-steel absorptivities were measured; they ranged between 38 and 59% depending on the laser power and the amount of liquid at the surface.

【 授权许可】

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