Effects of Heat Treatment Process on Mechanical Properties of X70 Grade Pipeline Steel Bends

Abstract:

Effects of heat treatment process of quenching and tempering under different temperature conditions on mechanical properties of X70 grade pipeline steel bends were studied. Brinell hardness, yield strength, tensile strength, elongation and impact absorbing energy of the bends were tested by using hardness tester, cupping machine and impact testing machine, respectively. It shows that the best heat treatment process of the X70 grade pipeline steel bends is quenching at 890 °Cand thermal insulation for 26 min then water cooling followed by tempering at 590 °C and thermal insulation for 60 min then air cooling. Furthermore, the resulting hardness, yield strength, tensile strength, yield ratio, elongation and impact absorbing energy reach HB230, 595 MPa, 725 MPa, 0.82, 28% and 300 J respectively, which has excellent comprehensive mechanical properties.

• Periodical: Applied Mechanics and Materials (Volumes 727-728)
• Pages: 322-326
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.727-728.322
• Online since: January 2015
• Authors: Shi Lu Zhao*, Zhen Zhang, Lian Chong Qu, Jun Zhang, Jian Ming Wang, Shuang Hong Wang
• Keywords: Heat Treatment Process, Mechanical Property, Pipeline Steel Bends, X70 Grade

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