Hydrogen embrittlement fracture of bolts is a common form of failure. Because hydrogen embrittlement fracture is delayed and concealed, the damage it brings is much greater than the damage caused by other fractures. Since this century, hydrogen embrittlement fractures of alloy steel bolts have been commonplace, seriously hindering the normal development order of aerospace models, and have reached the level of "talking about hydrogen discoloration". In order to enable more scientific and technical personnel to understand the mechanism of hydrogen embrittlement, grasp the law of hydrogen embrittlement of bolts, and effectively prevent the occurrence of hydrogen embrittlement of bolts, the results of these studies are now written and introduced for readers' reference.

Hydrogen embrittlement fracture of bolts is a common form of failure. Because hydrogen embrittlement fracture is delayed and concealed, the damage it brings is much greater than the damage caused by other fractures. Since this century, hydrogen embrittlement fractures of alloy steel bolts have been commonplace, seriously hindering the normal development order of aerospace models, and have reached the level of "talking about hydrogen discoloration". In order to enable more scientific and technical personnel to understand the mechanism of hydrogen embrittlement, grasp the law of hydrogen embrittlement of bolts, and effectively prevent the occurrence of hydrogen embrittlement of bolts, the results of these studies are now written and introduced for readers' reference.

Screw is a combination of simple machines—it is, in essence, an inclined plane wrapped around a central shaft, but the inclined plane (thread) also comes to a sharp edge around the outside, which acts a wedge as it pushes into the fastened material, and the shaft and helix also form a wedge in the form of the point. Some screw threads are designed to mate with a complementary thread, known as a female thread (internal thread), often in the form of a nut, or object that has the internal thread formed into it. Other screw threads are designed to cut a helical groove in a softer material as the screw is inserted. The most common uses of screws are to hold objects together and to position objects.

For the surface treatment of fasteners, people generally pay attention to aesthetics and anti-corrosion, but the main function of fasteners is to fasten parts, and surface treatment also has a great influence on the fastening performance of fasteners, so choose the surface When handling, the factor of fastening performance should also be considered, that is, the consistency of installation torque-pre-tightening force.

Generally, we analyze bolt fracture from the following four aspects: First, the quality of bolts Second, the pre tightening torque of bolts Third, the strength of the bolt Fourth, the fatigue strength of bolts

Fastener is a kind of mechanical part which is widely used for fastening connection. It is widely used in various machinery, equipment, vehicles, ships, railways, bridges, buildings, structures, tools, instruments, chemicals, instruments and supplies. It is the most widely used mechanical foundation. It is characterized by a wide variety of specifications, different performance uses, and standardization, seriation, generalization of the degree is also very high. Therefore, some people also call a kind of fastener with existing national standards as standard fastener, or referred to as standard fastener for short.

The steel structure enclosure system includes roofing system, wall system, lighting belt, edging and flooding, gutter and thermal insulation cotton. The enclosure system is one of the most important components of the light steel structure, which determines the ornamental appearance of the building, the waterproof and thermal insulation effect of the building. As an auxiliary fastener, self-drilling self-tapping screws play a vital role in the performance, quality and life of the overall building. It is not optimistic that as such an important basic component, our attention and research are far behind the attention and research on the main components of the building. The most prominent point is the neglect of the performance of fasteners and the main components of the building envelope system. match.

As a key functional part, high-strength fasteners play an important role in the function realization and safe operation of mechanical products. The correct use of high-strength fasteners is a link that cannot be ignored in the design and manufacture of mechanical products. At present, there is no unified method for the use of high-strength fasteners, and the practices of different industries and units are different. Therefore, it is necessary to communicate with each other and develop a scientific method of use to guide the design, manufacture, assembly and maintenance of products. Ensure the safe and stable operation of machinery. After researching and testing high-strength fasteners, this article summarizes the general use methods of high-strength fasteners from the aspects of characteristics, application, selection and assembly. Fasteners have a wide variety of specifications, large usage, and a wide range of applications. They are the most common type of standard parts in mechanical products. The reasonable selection of fasteners has also become an important part of the product design process. The correct use of the product directly affects the product's functional realization and safe operation. Compared with general fasteners, the use requirements of high-strength fasteners in product design, manufacturing, assembly, inspection and maintenance are very different. They also play a more critical role in the operation of equipment. Under the situation of diversified development such as large-scale, automation, and intelligence, high-strength fasteners are increasingly used as key functional parts, especially in critical occasions and important parts. At present, in the selection and use of high-strength fasteners, there are still various opinions and insufficient understanding, and it is necessary to do further research. This article mainly discusses the use of high-strength fasteners for mechanical products, and will not discuss the use of high-strength fasteners to replace general fasteners.