Industrial chains, as the core fundamental components of mechanical transmission and material conveyance, have a direct impact on the overall operating conditions and production efficiency of equipment through their stable operation. This article provides a systematic analysis of common failure modes, failure causes, and professional detection methods of industrial chains. Combined with practical prevention and maintenance schemes, it offers professional technical references for the scientific selection, use, and maintenance of chains in the industrial production field. This aims to assist enterprises in reducing the risk of chain failure, extending equipment service life, and ensuring production continuity.
1. Core Summary and Background
As an engaging transmission component with intermediate flexible elements, the chain combines the characteristics of gear transmission and belt transmission. Compared to gear transmission, it requires lower manufacturing and installation accuracy; compared to friction-type belt transmission, it has an accurate average transmission ratio and higher efficiency.
However, the disadvantages of chain transmission include its inability to maintain a constant instantaneous transmission ratio, high operating noise, and susceptibility to tooth jumping after wear. The report provides a detailed classification and analysis of the causes of various failure modes of chains.
The failure of industrial chains is not caused by a single factor, but is related to various aspects such as operating conditions, installation and maintenance, material selection, and load matching. Its common failure modes can be divided into normal wear and various abnormal failures. Different failure forms have distinct appearance characteristics and causes, which can be identified and determined through professional means.
2. Detailed explanation of main failure causes
The reasons for chain failure can be mainly summarized into three categories: wear, fracture, and corrosion, each of which has specific manifestations.
(1)Wear
Normal wear typically occurs in the load-bearing areas of the pin and sleeve, manifesting as gradual elongation of the chain. The rate of wear is significantly influenced by lubrication, and under proper lubrication, the load-bearing surface should exhibit a bright and smooth condition.
Excessive wear is characterized by the appearance of brownish-red oxides on the load-bearing surface, typically caused by insufficient lubrication leading to fretting corrosion. The generated abrasive oxides can significantly accelerate the wear process.
Abnormal wear is caused by insufficient lubrication or excessively high operating speed, which may lead to the detachment of metal particles from the load-bearing surface, and even the fracture of the welded joint between the pin and the sleeve mating surface.
We recommend our high-lubricity industrial chains for high-speed operating conditions to reduce abnormal wear risks.
(2)Fracture
Overload failure is a sudden failure that occurs when a chain is subjected to a load exceeding its design capacity. It primarily manifests in two forms: side plate fracture and pin shaft fracture.
Side plate fracture occurs when the instantaneous load borne by the chain exceeds its ultimate tensile strength, and it is a one-time overload failure.
Pin shaft fracture may also be a result of tensile overload, especially under vibration or impact loads. Even components that remain intact may suffer internal damage.
Fatigue failure is caused by repeated cyclic loads exceeding the bearing capacity limit of the chain. Its manifestations include side plate fatigue failure and sleeve fatigue failure, with the latter often manifesting as circumferential cracks near the sleeve connecting plate or along the length direction.
(3)Corrosion
Stress corrosion cracking (SCC) failure originates from operation in acidic, alkaline, or humid environments. Carbon steel and certain stainless steel chains are prone to SCC when exposed to such environments.
3. Inspection analysis and maintenance suggestions
The means of chain failure analysis include visual inspection, scanning electron microscopy (SEM) observation of fracture morphology, metal section analysis of microstructure, and mass spectrometry and energy dispersive spectroscopy (EDS) detection of chemical composition. These methods can effectively identify the microscopic characteristics of different failure modes such as fatigue, corrosion, and overload, including carbon segregationa along grain boundaries, corrosion particle residues, and abnormal grain morphology.
In maintenance practice, it is important to note that it is strictly prohibited to install a new chain on a worn sprocket; the selection of chain hardness should be based on the working conditions - under controlled pollution and sufficient lubrication, softer materials (HRC < 58) perform better, with a phenomenon of cyclic hardening; whereas in an open environment, high-hardness materials (HRC > 58) are required to resist abrasive wear, and the lifespan is determined by the wear degree of the hardened layer.All our industrial chain products are matched with dedicated sprockets to avoid premature wear from mismatched installation.
Under open working conditions, materials with higher hardness (such as HRC58) are more resistant to abrasive wear. Our industrial chains are customizable with HRC58 high-hardness material for open harsh environments, ensuring longer wear resistance.Understanding the cyclic hardening or softening phenomena that occur during chain use is of great significance for life prediction and selection design.
Conclusion
With the development of industrial equipment towards high efficiency and long-cycle operation, the reliability of chain drives is increasingly valued. In the future, a comprehensive preventive maintenance strategy combining materials science, lubrication technology, and intelligent monitoring will become a key direction for ensuring the safety of transmission systems and improving overall equipment efficiency.
