In the previous article "how to guarantee the strength and toughness of trailer axle? It also depends on the three processes of axle factory", the Editor takes the production process of Darong axle as an example, and introduces three processes: hot rotary rolling, hot quenching and tempering, and medium frequency induction strengthening. At the same time, he also mentions the axle fatigue test.

So, what is fatigue testing for? Why do trailer axles need fatigue tests? Today, let's go into the production workshop of Darong group and have a close look at the working condition of the fatigue test bench.

When choosing axles, many car owners want to know the basic situation of the products from all aspects, such as strength, toughness, bearing capacity, service life, etc. However, these data are often just a number or adjective, which makes many car owners feel boring. After reading and listening, they won't be impressed. In contrast, the fatigue test is more intuitive and transparent, which can fully show the performance of the axle.

Fatigue test is generally used to test the stress limit of the axle, that is, the maximum stress value after infinite stress cycles without damage, which can also be called the endurance limit value.

After the axle is installed on the trailer, it will continue to bear the variable load of the vehicle. If the axle quality is not qualified, after a period of time, it is easy to form small cracks in the local high stress area, and then the small cracks gradually expand, eventually leading to fracture and affecting driving safety.

The axle fatigue test bench fully simulates the working conditions of the axle, such as the various stresses on the axle when the vehicle is running with full load or when the owner is used to it. Through this repetitive loading condition, it can determine whether the strength, durability, toughness, etc. of the axle can meet the requirements of relevant standards.

For Darong conventional axle, the number of fatigue tests is generally set to be millions of times, which needs to last for about 72 hours. If it is a special vehicle such as a special vehicle for large cargo transportation, the test data will be adjusted according to the operating conditions.

After the fatigue test is completed, the axle will enter the magnetic particle flaw detection workshop to detect whether there are dark lines, cracks and other defects in the axle body. Only when the index requirements are met can the strength, toughness and durability be considered qualified.

The qualified axle only has the preliminary factory qualification, and the subsequent quality inspection procedures such as salt spray test will be carried out to further test the corrosion resistance and other properties of the axle. Only the axle whose performance fully meets the standard can be successfully delivered to the factory, so as to ensure that it does not have fatigue failure during the service period. With such an axle, car owners will naturally feel more relieved and relieved when using it.

It is also under such strict quality inspection that Darong axle / axle can always maintain a record of zero quality disputes in more than 20 years of entering the market. With reliable quality and real price, it has accumulated a large number of loyal customers. Its sales network covers the whole country and extends to more than 50 countries and regions such as Australia, America, Europe and Southeast Asia.