The causes of fatigue fracture of automobile girders, what are the causes of automobile girder fract

It's a quality problem.

Metal fatigue is the need for repeated deformation of metal to form, for example, if you take an iron wire and bend it repeatedly, it is best to fatigue and cause breakage.

If the girder is fatigue broken, you can imagine that in a normal car, the girder will hardly be deformed, so there will be no fatigue at all, only the quality problem can be explained.

1. Overview: It is mainly a large piece of the interior of the car, which carries almost all the weight of the car and the cargo. He also directly affects the driving safety of the car, so the deformation of the girder is basically bent.

The manufacturing process generally used is stamping and forming, and the requirements for the steel plate of the girder are also very high. It must have strong toughness, fatigue resistance, and cold formability, and the use of low-alloy high-strength and ultra-high-strength steel plates is the future development trend.

Second, the current situation: the use of ferrite-pearlite type materials has greatly improved the role of girder plates. It is mainly composed of low carbon, slightly high manganese, silicon elements, and also adds elements of many microalloys such as Ni, vanadium, and Qin.

It also uses solutions strengthening, precipitation strengthening, grain refinement and other processes for manufacturing, which achieves the desired strength and toughness.

3. Development: Through the proof of practice, if the bearing capacity of the car girder is improved, it will also bring safe driving and life protection. Low-alloy, high-strength and ultra-high-strength steel plates are still the future development trend of automobile beams.

Causes of car girder breakage.

1. Material: Due to the unqualified material, the fracture of the car girder will occur, and the treatment of the cause can only cure the root cause.

2. Overloading and speeding: This reason often occurs, and some drivers who drive desperately put themselves on top of the horizontal knife without asking.

Repair of car girder breaks.

1. Replace the girder: in the process of replacement, you should pay attention to matching with your own model, although the cost of replacement is very high, but your life is priceless.

2. Reset: The welding process is carried out directly at the broken or bent part of the girder, but the stains at the broken joint should be cleaned up in advance to prevent more serious re-damage after repair.

3. Digging and repairing welding: open a V-shaped groove at the disconnection, and cut off the material of the same size on the scrapped girder for welding repair.

Epilogue. It is necessary to clarify the cause of the fracture in order to use the correct method and obtain better safety guarantee.

Broken car girders are caused by long-term overplanting.

The reason for the use of inferior steel in the girder is that the quality of the girder steel used in the automobile factory is not good, and it cannot bear the designed load capacity, resulting in the breakage of the girder. In addition to reducing the specifications of the girder, some manufacturers in order to save costs, the web of the girder is connected by two shorter steels, and the bearing capacity must be much worse than the whole one.

There are two main reasons for the cracking of the lower wing plate, one is the technical problem of the welder, and the other is that the voltage is unstable during welding and is not welded well.

Many cases of broken girders are caused by improper use by users, the reason is that long-term overload, the cargo capacity exceeds the value of the trailer design, and the girder cannot bear the weight of the goods and causes breakage. Then there is the concentrated load, especially the popular light body hanging, the centralized load trailer is easy to break the girder.

The car that often runs in the mountainous area is easy to break the girder, and the twisting force of the trailer girder in the running mountain area is much greater than that of the flat road, and the specifications of the upper and lower wing plates and webs of the girder must be larger, otherwise it is easy to break the girder.

overload; girder rust; assembled vehicles; It was subjected to strong bumps, which caused the frame to deform.

The reason for this is the reason for the quality [the reason for excluding the load].