Flange bolt forging method

Abstract

The invention discloses a method for forging a flange bolt. The method comprises the following machining steps of: (a) manufacturing a rod blank by a casting process, wherein the rod blank comprises the following chemical ingredients in percentage by weight: 0.25 to 0.35 percent of C, 0.15 to 0.25 percent of Mn, 0.15 to 0.35 percent of Si, 0.01 to 0.04 percent of W, less than or equal to 0.025 and more than or equal to 0.015 percent of P, less than or equal to 0.035 and more than or equal to 0.015 percent of S, 0.15 to 0.20 percent of Ni, 0.025 to 0.045 percent of Ba, 0.02 to 0.03 percent of Sn, less than or equal to 0.02 percent of Mg and the balance of Fe; and (b) casting a cast rod for forming, forging at the temperature of between 600 and 650 DEG C for less than or equal to 25 times, covering thin-layer plant ash on the inner wall of a die cavity of a forging die, and turning the forged rod by utilizing a precision lathe to form external threads of the bolt, wherein the granularity of the plant ash is 200 to 300 meshes. According to the method for forging the flange bolt, the bolt is machined by using a cold extrusion process, so that the strength of the bolt is enhanced, a hardness value and a strength value which are required by the high-strength bolt of which the strength is 12.9 are reached, and the delayed breakage and fatigue breakage of the bolt under high strength are avoided; and the flange bolt is reliable in connection and difficult to break in the using process, so that the service life of the bolt is prolonged, and the using requirement of each industry in society on the high-strength bolt is met.

Description

technical field [0001] The invention relates to a bolt processing method, in particular to a flange bolt forging method. Background technique [0002] Flange 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 flange 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 method for processing flange bolts to produce bolts with better mechanical properties. ...

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