Discussion on tensile test control and selection of test rate of metal materials under high temperature conditions

In modern industry, the high-temperature mechanical properties of metal materials play a crucial role in ensuring the safety of various industrial applications. High-temperature tensile tests are essential for measuring key indicators, which support material development, engineering design, and quality control. However, the test rate control significantly impacts the test results, and different rates can lead to variations in material performance. Although the GB/T228.2 - 2015 standard has adjusted the high-temperature strain-rate control, due to diverse laboratory conditions, there remains confusion regarding the rate selection and control mode. This study aims to address this issue by deeply discussing the test rate control mode and selection strategy for metal materials’ high-temperature tensile tests. By interpreting the relevant standards, analyzing the influence of different control methods and rates on tensile performance, and considering various factors, this research provides a reference for the control and rate selection of high-temperature tensile tests, thus helping to improve the accuracy and reliability of the test results. The key conclusions are that Method A is more effective in reducing rate differences, enhancing the repeatability and comparability of the results, while Method B can be used as a supplement in equipment-limited laboratories. Additionally, sample size deviation, temperature, and equipment operating parameter fluctuations affect the accuracy of the test results, so laboratories need to take appropriate measures to control these factors.