Anti-fracture bolt forging method

Abstract

The invention discloses a method for forging a fracture-resistant bolt. The method comprises the following steps of: a) casting a U-shaped rod material blank, and controlling the weight percentage of all chemical components of the rod material blank to ensure that the fracture-resistant bolt comprises 0.28 to 0.35 percent of C, 0.25 to 0.35 percent of Mn, 0.05 to 0.09 percent of V, 0.15 to 0.35 percent of Si, 0.01 to 0.04 percent of W, less than or equal to 0.025 percent of P, less than or equal to 0.035 percent of S, 0.55 to 1.20 percent of Ni, 0.35 to 0.45 percent of Co, 0.20 to 0.30 percent of Sn, and less than or equal to 0.20 percent of Al; and b) forging and forming the U-shaped rod material formed by forging, wherein the forging temperature is controlled to be 650 to 700 DEG C, thin-layered graphite powder covers on the inner wall of an impression of the forging die, the particle size of the graphite powder is controlled to be 200 to 300 meshes, and the forging frequency is less than or equal to 25 times, and turning an outer thread of the bolt by using a fine turning lathe after forging and forming. According to the method for forging the fracture-resistant bolt, the bolt is machined by a cold extruding process, so that the intensity of the bolt is improved, the harness value and the intensity value which are required by a 12.9 high-intensity bolt can be acquired, and the delayed fracture and the fatigue fracture of the bolt under high intensity are avoided; during use, the bolt is reliable in connection, is not prone to break, and meets the using requirements of all industries in the society on the high-intensity bolt; and the service life of the bolt is prolonged.

Description

technical field [0001] The invention relates to a bolt processing method, in particular to a forging method for a fracture-resistant bolt. Background technique [0002] High-strength bolts are commonly used fasteners in the machinery industry. The current processing method is generally turning and forming, and the strength is often difficult to guarantee. Sometimes unsafe phenomena such as U-turn and rod breakage occur during use, which is very harmful to industrial production. Therefore, it plays an important role in the development of technology and economy to study and improve the production method of high-strength bolts to ensure the quality stability of high-strength bolts. In addition, when the bolts are in a relatively humid environment, they are prone to rust and corrosion, eventually leading to breakage or cracks, forming a potential source of accidents. [0003] In view of this, it is necessary to provide a processing method for high-strength bolts to produce high...

AI Technical Summary

Problems solved by technology

In addition, when the bolts are in a relatively humid environment, they are prone to rust and corrosion, eventually leading to breakage or cracks, forming a potential source of accidents