In the heart of China’s bustling construction industry, a silent enemy has been wreaking havoc on concrete pump trucks, leading to unexpected failures and significant economic losses. This enemy is not a rival company or a market fluctuation, but a microscopic process called corrosion fatigue. A recent study published in Cailiao Baohu, translated to Materials Protection, sheds light on this issue, offering insights that could revolutionize the way we approach the durability and safety of these crucial machines.
The research, led by ZHAO Jun and his team from Chengdu Metallurgical Experimental Plant Co., Ltd., focuses on the failure of the first-level boom in a concrete pump truck. This boom, made from 20MnTiB steel plate, is a vital component that extends to pour concrete into high-rise buildings and other structures. However, during operation, the upper surface of this boom can fracture, leading to costly repairs and downtime.
The team conducted a series of physical and chemical tests on the fractured boom, including scanning electron microscopy and metallography. Their findings paint a clear picture of the failure process. “The fracture originated from a localized pitting corrosion on the inner surface of the boom,” explains ZHAO Jun. “This corrosion then propagated under the influence of corrosive media and cyclic stress, leading to corrosion fatigue crack growth.”
But what causes this pitting corrosion? The researchers found that the earliest pitting corrosion pit was located on a coarse martensite layer on the surface of the damaged steel plate. This damage was attributed to the welder’s arc-striking operation during the welding of the boom box, which created a layered structure similar to that of a weld joint.
The implications of this research are significant for the construction and energy sectors. Concrete pump trucks are not just used in building construction but also in energy infrastructure projects, such as the construction of wind turbines, power plants, and oil refineries. The failure of these trucks can lead to delays and increased costs, which can have a ripple effect on the entire project.
Moreover, the findings of this study could shape future developments in the field. For instance, manufacturers could develop new welding techniques that minimize damage to the steel plate surface, reducing the risk of corrosion fatigue. They could also explore new materials or coatings that are more resistant to pitting corrosion.
The energy sector, in particular, could benefit from these advancements. As the demand for renewable energy sources grows, so does the need for efficient and reliable construction equipment. By addressing the issue of corrosion fatigue, we can ensure that our concrete pump trucks are up to the task, helping to build a sustainable future.
In the meantime, companies operating concrete pump trucks should be aware of the risks posed by corrosion fatigue. Regular inspections and maintenance could help detect early signs of pitting corrosion, preventing catastrophic failures. As ZHAO Jun puts it, “Prevention is always better than cure. By understanding the root cause of these failures, we can take proactive steps to mitigate the risks.”
The study published in Materials Protection is a significant step forward in our understanding of corrosion fatigue in concrete pump trucks. It offers valuable insights that could help shape the future of the construction and energy sectors. As we continue to push the boundaries of what’s possible, it’s crucial that we also ensure the durability and safety of the equipment that makes it all possible.
