Mechanical and Process Performance of Quenching and Tempering Steel Reinforcing Bars (GB 13014-1991)
Introduction
Quenching and tempering is a common process applied to steel reinforcing bars (rebars). This process is used to increase the mechanical and process performance of the bars. The purpose of this essay is to outline the relevant standards and regulations set by the General Administration of Quality Supervision, Inspection and Quarantine of the People’s Republic of China (AQSIQ) surrounding the quenching and tempering of steel reinforcing bars. This essay will specifically reference the GB 13014-1991 standard for the mechanical and process performance of quenching and tempering steel reinforcing bars.
Standard of GB 13014-1991
In the GB 13014-1991 standard for the mechanical and process performance of quenching and tempering steel reinforcing bars there are various requirements that must be met for the bars to be deemed suitable for use.
The tensile strength of steel reinforcements should reach the standard of Grade III or higher. The reinforcement should yield strength not being less than ten times the actual stress (MPa). The total elongation percent should reach or exceed 17%. The Ratio of Yield Strength to Tensile Strength of steel reinforcing should reach no less than 1.1%. The bending performance of rebar should reach no less than 90°or follow the yield strength in the standard without any cracking.
Process Performance of Quenching and Tempering Steel Reinforcing Bars
Steel reinforcing bars quenched and tempered according to GB 13014-1991 should also meet specific process performance requirements.
The surface condition of the steel reinforcing bars should at a minimum contain no visible sparks or other foreign matter that could effect its performance. The incidence of defects should not exceed the maximum specified by the standard. The nominal diameter tolerance should range from -0.20 mm to + 0.50 mm for external diameters and from + 0.00mm to + 0.20mm for internal diameters. The treatment process should also take into account the impact on the material’s performance such as surface hardness and other properties.
Conclusion
In conclusion, theGB 13014-1991 standard outlines the requirements to ensure the mechanical and process performance of quenching and tempering steel reinforcing bars is up to the required standard. This serves to ensure that these steel reinforcing bars are suitable for their intended use and can be relied upon to perform in accordance to the designed purpose.
