Effect of Boron or Cuprum on Phase Transition and Mechanical Properties of High-Strength Steels for Oil Tank

Abstract:

Two kinds of oil tank steels were fabricated by added B(B-steel) and Cu(Cu-steel) , and their microstructures, tensile and Charpy impact properties, undercooled austenite transformation were investigated. In this work,0.0016%B can improve hardenability distinctly. The B-steel was mainly composed of bainite at the cooling rate of 3°Cs^-1, but the Cu-steel completely consisted of bainite when the cooling rate exceed 20°Cs^-1. The steels manufactured by thermo-mechanical controlled process , test results indicated that the B-steel had the higher yield and tensile strength than the Cu-steel ,because their volume fractions and morphologies of bainite. The Cu-steel had the higher impact energy than the B-steel because of their higher effective grain size. Majority of the precipitation particles which were compounded of Nb and Ti existed as（Nb_x,Ti_(1-x)) (C_yN_(1-y)).

• Periodical: Advanced Materials Research (Volumes 233-235)
• Pages: 1063-1066
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.233-235.1063
• Online since: May 2011
• Authors: Liang Qi, Ai Min Zhao, Zheng Zhi Zhao
• Keywords: Boron, CCT Curve, High-Strength, Oil Tank, Precipitation Particles

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