Method for machining high-strength double end bolt

A technology of stud bolts and processing methods, applied in the direction of screws, threaded fasteners, connecting components, etc., can solve the problems of accident source, fracture or crack, easy rust and corrosion, etc., to improve tensile strength and moderate hardness , the effect of high bolt accuracy

Active Publication Date: 2013-05-08
ANHUI LIUFANG ZHONGLIAN MECHANICAL SHARE
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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

Method used

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Examples

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Embodiment Construction

[0018] The present invention will be further described in conjunction with the following examples:

[0019] A high-strength stud bolt processing method, the processing steps include:

[0020] a. The weight percentage of each chemical composition of the rod material blank and the control rod material blank should meet the following requirements: C 0.28~0.35, Mn 0.25~0.35, V 0.05-0.09, Si 0.15~0.35, W 0.01-0.04, P ≤0.025, S≤0.035, Ni 0.55~1.20, Co 0.35~0.45, Sb 0.20~0.30, Cu≤0.20;

[0021] b. Carry out forging and forming processing on the rod material after casting. The forging temperature is controlled at 750-800°C. A thin layer of fly ash is covered on the inner wall of the forging mold cavity. The number of forgings is not more than 20 times. After forming, use a precision lathe to turn the external threads at both ends of the bolt;

[0022] c. Heat treatment, the first time is to heat the external thread at both ends of the turned bolt at 400-450°C for 10-12 hours, then r...

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PUM

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Abstract

The invention discloses a method for machining a high-strength double end bolt. The method comprises the following steps of: a, manufacturing a rod blank, and controlling the weight percentage of each chemical component of the rod blank to meet the following requirements: 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 Sb and less than or equal to 0.20 percent of Cu; and b, forging a cast rod at the temperature of between 850 and 800 DEG C for not more than 20 times, wherein a thin layer of fly ash is coated on the inner wall of an impression of a forging die; and turning an external thread at each of two ends of the bolt by using a precision lathe after forging. According to the method for machining the high-strength double end bolt, the bolt is machined by adopting a cold extrusion process, so that the strength of the bolt is improved, the hardness value and the strength value required by the 12.9 high-strength bolt are achieved, the problems of delayed fracture and fatigue fracture of the bolt under high strength are solved, the bolt is reliable in connection during use and difficult to break, the service life of the bolt is prolonged, and the using requirement of each industry in the society for the high-strength bolt is met.

Description

technical field [0001] The invention relates to a bolt processing method, in particular to a high-strength stud bolt processing method. 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 more co...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): F16B35/00C22C38/12C23F17/00
Inventor 王立新
Owner ANHUI LIUFANG ZHONGLIAN MECHANICAL SHARE
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