Dynamic tear test of metal materials

The dynamic tear test refers to a test in which a dynamic tear sample in a simply supported beam state is broken once on a dynamic tear testing machine to measure its energy absorption and fiber section ratio. The dynamic tear test of metal materials can determine the dynamic tear energy and fiber section ratio of metal materials or welded joint samples with a Rockwell hardness value less than 36HRC.
Zhongke Testing Reliability Experiment Center has the capabilities of environmental testing and reliability performance testing of various metal materials, and provides professional dynamic tear testing services for metal materials.

Metal materials are usually divided into ferrous metals, non-ferrous metals and special metal materials.
1. Ferrous metals include chromium, manganese and their alloys.
2. Non-ferrous metals refer to all metals and their alloys except iron, chromium and manganese, which are usually divided into light metals, heavy metals, precious metals, semi-metals, rare metals and rare earth metals.
3. Special metal materials include structural metal materials and functional metal materials for different purposes. Among them are amorphous metal materials obtained through rapid condensation processes, as well as quasicrystalline, microcrystalline, and nanocrystalline metal materials; there are also special functional alloys such as stealth, hydrogen resistance, superconductivity, shape memory, wear resistance, vibration reduction and damping, and metal matrix composite materials.

1. Before the test, immerse the sample on the sieve plate of the thermal insulation tank equipped with cooling or heating medium. The sieve plate is at least 25 mm from the bottom of the tank, and the distance between the samples is at least equal to the thickness of the sample. The temperature in the tank should be uniform. The difference between the temperature of the medium and the test temperature should be controlled within the range of ±1°C. The holding time is calculated as 1 min/mn, but the holding time should be at least 15 min.
2. The minimum graduation value of the glass thermometer used for temperature measurement should not be greater than 1°C, and the error should comply with the regulations of JIG 130; the temperature measuring thermocouple should comply with the requirements of Class II thermocouples in JJG 141, JJG 351 or JJG 368; the error of the temperature measuring instrument should not exceed ±0.1%; the temperature of the reference end of the thermocouple should remain constant, and the deviation should not exceed ±0.5°C.
3. The removal of the sample from the heat preservation tank to the punching should be completed within 10 s. If it exceeds 10 s without testing, the sample should be put back into the heat preservation tank and kept warm for at least another 10 minutes. Clamps that are significantly different from the test temperature shall not be used to clamp the specimen near the notch.
4. The specimen should be placed close to the support, and the center line of the impact blade should be aligned with the top of the notch, with the deviation within ±0.8 mm.
5. Break the sample and record the test temperature and dynamic tearing energy value.
6. At each test temperature, test at least two samples.

GB/T5482-2007 Metallic materials Dynamic tear test method
TB/T 2985-2000 Dynamic tear test method for metallic materials
GB/T 2975 Steel and Steel Products Mechanical Property Test Sampling Location and Sample Preparation
GB/T 3808 Inspection of pendulum impact testing machine
GB/T12778 Metal Charpy impact fracture determination method