Prefabricated steel frame for high-toughness bridge and manufacturing method for prefabricated steel frame

Abstract

The invention discloses a prefabricated steel frame for a high-toughness bridge and a manufacturing method for the prefabricated steel frame. The prefabricated steel frame for the high-toughness bridge is made of low carbon alloy steel, a carburized layer is solidified on the surface of a base body of the prefabricated steel frame, wherein the thickness, detected according to a standard hardness method, of the carburized layer is 0.8-1.2 mm, and the highest carbon concentration is 0.8-1%. The outer surface of the prefabricated steel frame for the high-toughness bridge is further plated and coated with a cadmium layer with the thickness being 0.08-0.12 mm. The manufacturing method comprises the steps that the prefabricated steel frame is precast and formed by the low carbon alloy steel, thesurface layer of the prefabricated steel frame is subjected to carburization, cold treatment is performed, step quenching is performed according to a special technique, a base body with good toughness is obtained, and then electroplating of cadmium is performed. The prefabricated steel frame for the high-toughness bridge is high in strength, extremely good in toughness, high in anti-corrosion capability and high in anti-fatigue ability.

Description

technical field [0001] The invention relates to the field of bridges, in particular to a prefabricated steel frame for high-toughness bridges and a manufacturing method thereof. Background technique [0002] Steel bridge is a bridge whose main load-bearing structure is made of steel, that is, a steel structure bridge or a steel bridge. Prefabricated steel bridges are widely used all over the world. The original fabricated steel bridge was designed by British engineer Donald Bailey in 1938 at the beginning of World War II. The main design concept is to assemble the least types of unit components into a prefabricated steel bridge capable of carrying various loads and different spans, and it only needs to be transported by ordinary medium-sized trucks. In special cases, it can be built entirely by manpower. [0003] According to relevant research, the failure modes of steel structure bridges mainly include: due to the long-term bearing of heavy-duty vehicles to the fatigue fr...

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Problems solved by technology

[0004] In the relevant patents that have been applied in China, there is no disclosure of materials and methods for improving the toughness of bridge prefabricated steel frames. They are only improved structurally, but the surface integrity design is not adopted in the structure. The manufacturing materials are generally carbon steel or low-carbon steel. For alloy steel, painting is generally used for anti-corrosion treatment, and prestressing is generally used for anti-fatigue treatment. Such a prefabricated steel frame itself has poor mechanical strength and toughness, and the paint itself will fall off in the natural environment, and its bonding force with the substrate is also weak. low, and the prestressing mode is too targeted, and is generally obtained by directly changing the prefabricated steel frame structure, which actually directly reduces the fatigue limit and fatigue life of the prefabricated steel frame