test method used to evaluate the mechanical properties of forgings
Tensile test and impact test
Tensile test
By applying axial tensile force to the sample cut and processed from the forging on the tensile testing machine, so that the sample gradually undergoes elastic deformation, plastic deformation until it breaks, thereby measuring the tensile strength, yield strength, elongation, cross-sectional shrinkage and other important mechanical performance indicators of the forging material, so as to evaluate the performance of the forging when subjected to tensile loads and determine whether it meets the design and use requirements.
Impact tests
Generally placing the processed impact sample on the impact testing machine, using the pendulum to impact the sample to break, recording the impact energy absorbed by the sample during each impact, and obtaining three impact absorption energy values. This test is mainly used to measure the resistance of forging materials when subjected to impact loads, reflect the toughness and other properties of the material, and understand the reliability and stability of forgings under dynamic loads.
Purpose
Evaluate material properties
Tensile tests can obtain indicators such as tensile strength and yield strength to measure the material's ability to resist tensile loads; the impact absorption value of the impact test can reflect the toughness of the material under dynamic loads.
Control product quality
Comparing the test results with the standard can determine whether the forging is qualified; testing multiple batches of forgings can timely discover problems in production, facilitate process adjustment, and ensure stable quality.
Provide a basis for design
The test data can provide a reference for the reasonable selection of materials, determination of part size and structure for product design; for forgings with new designs or new materials and new processes, the rationality of the design can be verified so that timely modifications and optimizations can be made.
What workpieces are suitable for
Shaft workpieces
Such as automobile drive shafts, engine crankshafts, etc. These shaft workpieces are subjected to large torque, bending moment and impact force during operation. Through the "one pull and three impact" test, their tensile strength and ability to resist impact load can be evaluated to ensure that no failure forms such as fracture will occur during use.
Gear workpieces
Like the gears in the transmission, the gear teeth not only have to bear the stress generated by the transmitted torque during the transmission process, but also the impact load caused by operations such as shifting. The "one pull and three impact" test helps to determine the strength and toughness of the gear material, ensure that the gear can work reliably under complex working conditions, and prevent failures such as gear tooth breakage.
Connecting rod
The connecting rod of the engine is subjected to complex stresses such as periodic tension, compression and bending during operation. The "one pull and three impact" test can effectively detect whether the mechanical properties of the connecting rod material meet the requirements, ensure that the connecting rod has sufficient strength and toughness during the operation of the engine, and avoid problems such as fatigue fracture
Bolt and nut
High-strength bolts, nuts and other connectors play an important role in fastening and connecting in mechanical structures, and need to withstand large tensile forces and possible impact loads. Through the "one pull and three impact" test, its tensile strength and impact resistance can be verified, the reliability of the connection can be guaranteed, and loosening and breakage during use can be prevented, thereby ensuring the safety of the entire structure.
Aerospace structural parts
Such as aircraft landing gear parts, wing connection structural parts, etc. These parts are subjected to huge loads and complex stress environments during the take-off and landing and flight of the aircraft. Performing "one pull and three impact" tests on them is an important means to ensure the safety and reliability of aerospace structures, which can ensure that the parts have sufficient mechanical properties under extreme conditions and ensure flight safety.
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