In order to study the effect of supply chain on vehicle whole life cycle carbon emission, this article collects the carbon emission data of the supply chain through China Industrial Carbon Emission Information System (CICES), aims to study and analyze the carbon emission of the whole life cycle of a vehicle. The results show that the upstream and downstream supply chains such as raw material production, parts production and the using stage of the vehicle are the main factors affecting the carbon emission of the life cycle of the vehicle, and suggestions on carbon emission management of the supply chain are put forward.

This article firstly introduces the current situation of the evaluation of robot usage status, and then proposes a method of evaluating robot operation status based on the time dimension, and presentes the concept of robot utilization rate as well as the visualization display method. A robot running time acquisition method based on big data and industrial internet is introduced, and a corresponding algorithm is designed to process the acquired data. Moreouer, the cycle operating time reflecting the actual operating state of the robot is calculated, which as displayed visually. Finally, combined with specific cases, the value of visualization of the robot utilization rate is introduced. By comparing the utilization rates of robots at different stations in the same production line or in different production lines, this paper provides optimization direction for the production line cycle time and production capacity promotion.

To avoid the risk of incorrect parts, incorrect positions, incomplete or missed assembly during the production process of automobile final assembly, a final assembly error-proof system is established from 4 dimensions: design, process, logistics, and management. The working principles and application points of error-proof sub dimensions such as product generalization, structural error-proof, color error-proof, identification error-proof, process route error-proof, process card annotation, code scanning error-proof, intelligent tightening system, industrial vision system, SPS logistics mode, intelligent lighting system, BOM management, breakpoint management, etc., are elaborated and illustrated. It is pointed out that the combination of various dimensions is necessary to achieve good error-proof effects.

Currently, with the continuous improvement of engine performance, the working environment of the valve guide has become more harsh, so the failure problem of the valve guide has become more and more common. A comparative analysis of the durable and failed components of the engine exhaust valve guide is conducted to identify the causes of material failure. The wear resistance, microstructure, and porosity of the valve guide are studied. The results show that the wear test results of the 2 specimens are consistent with the bench test results, and the failed specimen experiences wear serious. The microstructure of both is consistent with a small amount of pearlite and a large amount of irregular pearlite and alloy phase and pores. The porosity results indicate that the durable specimen has a higher porosity ratio, storing more oil and with a density meeting the standard. However, the failed specimen has a large hole with a diameter of 100 μm, which reduces its wear resistance. Therefore, the cause of wear failure is identified as lower porosity and the existence of larger pores.

In this paper, corrosion properties of 3 heat treatment-free die casting aluminum alloys to 2 typical integrated die casting die steels are studied through dynamic rotary immersion test in molten aluminum alloy. The results show that after 20 min rotary immersion test, die steel samples in 1# molten aluminum alloy has the smallest corrosion area and mass loss. As a result, 1# aluminum alloy has the smallest die soldering tendency. Therefore, in the application of new heat treatment-free material, it is important to choose a die material which fits well with this heat treatment-free die casting aluminum alloy to obtain the smallest corrosion mass loss, and ensure the service life of die.

The effect of cooling water between rolling mills on the surface microstructure uniformity of UF340 was investigated using hot rolling experiments and full-process tracking. The results show that the cooling water between rolling mills has certain effect on the organization uniformity of the hot rolled coil along the transverse direction, and will be partially inherited to the final UF340 strip organization. When the cooling water between rolling mills is fully open, a small amount of non-recrystallized grain is retained on the surface of the final UF340 strip located at about 1/4 from the edge. When the latter part of water between rolling mills is closed, due to the full recrystallization during hot rolling, the final product has a better consistency of the organization along the transverse direction, presenting a fine and fully recrystallized tissue on the surface, which is beneficial to improving surface Distinctness of Image (DOI) of the material. The extraordinary uniformity of the microstructure makes the waviness of the UF340 after painting and deforming is as low as 0.169 μm, and DOI value reaches 92, which fully meets the requirements of the surface quality for the intercoat-free coating process.

The effects of pre-strain and baking on the microstructure and mechanical properties of QP980 cold rolled sheet were studied by means of universal tensile testing machine, pendulum impact testing machine, Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD). The results show that with the increase of pre-strain, the ultimate bending properties and impact properties of QP980 cold rolled sheet decrease After baking at 170 ℃ for 20 min, the impact properties of the material increase, and the Bake Hardening (BH) properties increase with the increase of pre-strain; X-ray diffraction analysis shows that baking does not cause phase transformation, and the carbon content in residual austenite decreases; Scanning analysis shows that the ductile fracture area in the impact fracture increases significantly after baking treatment.

As a new type of ultra-fine grained high-strength steel, UF340 has the potential to replace HC180BD in automotive exterior panels. This paper investigated its mechanical properties and formability. The results indicate that UF340 and HC180BD have similar mechanical properties in terms of plasticity, processing hardening index, and anisotropy, but UF340 does not exhibit significant bake hardening properties. The formability of the two materials is similar. There is certain difference between the forming limit curve calculated by the Keeler model and the forming test results. The forming limit diagram obtained by linear segment fitting data has a higher degree of agreement with the experiment, the forming limit curve obtained by this method can provide a reference on the forming application of new materials.

Failure analysis of the 34MnB5 hollow stabilizer bar fracture occurred in the road test of a mass production vehicle was carried out using laser confocal microscopy, scanning electron microscope and other equipment. It was confirmed that the insufficient shot blasting process time and the existence of axial original cracks caused early fatigue failure and fracture of the stabilizer bar. In order to further clarify the root cause of the failure and fracture, this article investigated and analyzed the manufacturing process of the stabilizer bar, determined that the main cause for the fracture of the stabilizer bar was insufficient shot blasting time, thus evaluated the subsequent impact of this fracture failure accident. Finally, the article identified the direction of rectification for the risk points during the investigation process, and proposed optimization measures to further prevent the occurrence of such problems.

The aluminum alloy vacuum high-pressure die-casting technologies are gradually applied in the automotive industry. This paper studied and analyzed the material, process, product and the key issues at present stage of the vacuum high-pressure die-casting, summarized the physical characteristics, chemical compositions and mechanical properties of heat treatment materials and heat treatment free materials in detail, elaborated the technical process, production line, process design, process parameter and formability properties of vacuum high-pressure die casting, analyzed the main issues at present stage including product performance, thickness, dimensions, connection, repair and die. The paper also summarized the advantages of vacuum high pressure die-casting technologies and forecasted its development prospects.