Metal tension experiment is an important research method in the field of mechanical engineering, which can effectively detect the performance of metals. The national standard of GB 228-87 was issued to regulate the detection and analysis of tension performance of metals. Through strict control of the testing procedures and data analysis, the quality evaluation of mechanical products can be realized.
First of all, the GB 228-87 standard defines the basic requirements and the possible hazards in the tensile test of the metal. For example, the space required for the experiment, the selection of the test system, in order to ensure that the test environment is safe and reliable. In addition, the preferred test models and materials are also clarified in the standard. For example, the preferred test model should be a universal testing machine, the test materials should comply with the national standard and their sp(e)cifications.
Secondly, the standard has clear requirements for the preparation of the samples, including the test area, elimination of permanent deformations and size deviation, etc. It also points out that the tensility tests should be performed parallel to the direction of tension in the test system. Meanwhile, it requires optimized test areas so that they can be more easily tested.
Moreover, the GB 228-87 standard provides set safety measures to ensure accuracy and reliability of the tension tests. The essential requirement is that the testing data must be inspected, if the values do not meet the demand, the measurement must be repeated. Some accompanying notes are also provided in the standards to further guide the testers, such as preparing the test results in detail; making sure the mechanical and electrical devices are correct before the test; etc.
In addition, the standard also provides a variety of test methods for different metal materials. Each test method has been evaluated by the national standard authority and thereby permissible safety margins are ensured. For example, the tensile tension test is an important index of the mechanical performance of the materials, and the methods for testing the tensile strength, yield strength and total elongation of the materials are specified in detail.
Finally, the GB-228-87 standard also gives two basic requirements for the raw data processing, the sample drawing and the data analysis. For raw data processing, the requirements of calculation mode, calibration cycle and accuracy must be met.Moreover,the sample drawings must meet the requirements of the standard and indicate the reference line clearly. Additionally, the data analysis is also need to be processed, including the maximum, minimum and average values as well as the examination of data reliability.
In conclusion, the national standard GB 228-87 has provided a systematic and comprehensive reference for the tension experiment of metals. The strict implementation of standards and regulations can ensure the accuracy, reliability and safety of metal tension tests. This serves as an effective measurement technique to determine the properties of metal materials and to evaluate the quality of mechanical products.
