Non-drive axle quality appraisal

non-drive axle takes mechanical transmission and structural bearing as its core principles, and realizes vehicle support and steering functions through axle housings, wheel hubs, suspension systems and other components. It is widely used in commercial vehicles, engineering machinery, special vehicles and other fields. In logistics and transportation, it undertakes the load-carrying tasks of heavy trucks; in engineering operations, it serves as a walking support for excavators and loaders; in the field of special vehicles, it is used for the stable driving of explosion-proof vehicles and rescue vehicles. Compared with the drive axle, the non-drive axle has the characteristics of high static load, low dynamic response, long fatigue life, etc., and is a key component for the safe operation of the vehicle.

Zhongke Testing is a product quality appraisal service organization registered with the court. It can provide non-drive axle quality appraisal services. It has a professional appraisal team and advanced instruments and equipment to provide fair and accurate appraisal results for non-drive axle quality appraisal.

With the development of lightweight and heavy-duty vehicles, non-drive axle quality dispute cases are gradually increasing. The judicial dispute focuses on:

1. Disputes over performance indicators: whether the actual load-bearing capacity meets the standard and whether the fatigue life meets the contract requirements;

2. Material defects: the axle housing material has insufficient strength, Improper matching of welding materials;

3. Process problems: The welds were not fused and improper control of the heat treatment process resulted in coarse grains;

4. Contract performance issues: The delivered bridge body did not comply with the technical agreement.

1. Appearance inspection: Check the overall appearance of the non-drive axle, including whether there are deformations, damages, scratches and other defects.

2. Dimensional measurement: measure the dimensions of each component other than the drive axle, compare with the design drawings, and check whether there are dimensional deviations.

3. Material analysis: Analyze the main materials of non-drive axles to check whether they meet material specifications and whether there are impurities or defects.

4. Mechanical performance test: Conduct load-bearing test, torque test, etc. on the non-driving axle to check whether its mechanical properties meet the requirements.

5. Durability test: Conduct a durability test on the non-drive axle to simulate actual use conditions to check whether its service life meets the design requirements.

A logistics company of the applicant signed a "Non-Drive Axle Procurement Contract" with an auto parts company of the respondent, agreeing to purchase 50 sets of NDQ-120 axles for heavy-duty trucks. After 3 months of use, cracks appeared in multiple axle housings, causing cargo transportation to be interrupted. The logistics company believed that the bridge body had quality defects and demanded compensation for losses. The parts company argued that the problem was caused by overloading, and both parties went to court.

Identification analysis results:

The quality analysis expert group discussed and comprehensively analyzed the relevant information of the "non-drive axle", contract technical agreement, on-site investigation case materials and other data, and made the following quality analysis opinions:

The axle shell material of the non-drive axle involved in the case is Q235B steel (contract requirement Q345B), and the yield strength is only 240MPa (standard ≥345MPa); the welding material is E4303 electrode (contract requirement E5015), and the weld strength is insufficient. The unfusion depth of the weld reaches 3mm (standard ≤1mm), and the flaw detection pass rate is only 80%; the heat treatment process is not implemented according to the standard, and the grain size is coarse (grain size 6, standard ≥8).

The parts company failed to provide the specified material axle housing and welding materials according to the contract, and the process control was not up to standard, resulting in equipment problems.

Non-drive axle quality appraisal report should include the following content:

1. Appraisal purpose and basis.

2. Model, specification, manufacturer and other information of the equipment being identified.

3. Identification method.

4. Identification results (including whether there are quality problems, causes of problems, etc.).