1.Room Temperature Tensile Test
According to the testing standards, samples are cut from heat-treated 4145H steel into plate-shaped specimens. The gauge length of the specimen is 12 mm, and the parallel section length is 21 mm. The dimensions of the tensile specimen comply with relevant standards. The surface is polished stepwise using 150# to 600# sandpaper until smooth. A universal tensile testing machine (AG-X PLUS) is used to conduct the room temperature tensile test. The force-displacement curve is measured and converted into a stress-strain curve. The test is performed at room temperature with a tensile speed of 3 mm/min. The tensile strength, yield strength, elongation after fracture, and reduction of area are determined. To minimize errors, three parallel samples are prepared and tested for each heat-treated specimen.
2.Impact Test
Impact samples are cut longitudinally from 4145H steel plates according to testing standards. A Charpy impact test is conducted using an Si instrument impact testing machine. The samples feature a V-notch with a depth of 2 mm and dimensions of 10 mm × 10 mm × 55 mm, complying with relevant specifications. The impact test is performed at room temperature with an impact speed of 7 m/s.
3. Microhardness Test
A TMHVS-1000 Vickers hardness tester is used to measure the hardness of 4145H steel in its original, quenched, and tempered states. This method involves pressing a diamond pyramid indenter into the alloy surface and calculating the microhardness based on the diagonal length of the indentation. The test specimens include metallographic samples in their original, quenched, and tempered conditions. To reduce errors, 10 hardness measurements are taken for each specimen. The testing procedure is as follows: the specimen is placed in a fixture and positioned on the stage. The device is then zeroed, and the focus is adjusted until the microstructure is clear. A load of 1.5 kg is applied and held for 15 seconds.
This testing process ensures accurate evaluation of the mechanical properties and hardness of 4145H steel, providing reliable data for its application in demanding environments.
Post time: Feb-28-2025
