Influência dos tratamentos térmicos de recozimento pleno e normalização na microestrutura e propriedades mecânicas de aços com baixo e alto teor de carbono

Abstract

Carbon steel is an iron-carbon alloy containing generally 0.008% to 2.11% carbon, in addition to certain residual elements, and can be divided into steel with low, medium and high carbon content. In the following work, the behavior of a low carbon steel was analyzed when subjected to full annealing and normalization treatments at 920ºC and a high carbon steel subjected to the same treatments at 770ºC. In the full annealing of the high carbon steel, care was taken to ensure that the acm line was not exceeded so that no carbide envelopes were formed in the grain boundaries, which would weaken the material. Comparing the steels with the same carbon content submitted to different heat treatments, a grain increase is noticed for the annealed steels in relation to the normalized steels. Hardness tests were also carried out to verify that a hardness decrease occurs for full annealing and an increase in hardness at the normalization.