Fastener

Abstract

The invention discloses a fastener which is provided with a threaded section. Metal materials for manufacturing the fastener comprise the following chemical components including, by weight, 0.08%-0.4%of C, 0.10%-0.80% of Si, 0.20%-1.8% of Mn, 0.12%-3.0% of Ni, 0.10%-0.60% of Cu, 0.30%-1.25% of Cr, 0.015%-1.8% of Al, 0.009%-0.019% of V, Fe and unavoidable impurities. The toughness, the strength, the crystal density and the like of steel are obviously improved through the metal materials for manufacturing the fastener, and the impact bending resistance of the fastener is improved. Alloys can permeate into the surface of the steel to form a plating layer, so that electrochemical corrosion is prevented from occurring when the threaded section is connected with other metal components, high plating layer adhesive force is achieved, the brittleness problem caused by adding copper into the steel can be balanced, and the use amount of nickel, chromium and molybdenum is reduced on the aspect ofcorrosion resistance of the steel. In order to achieve the purposes that the alloys permeate into the surface of the steel to form the plating layer and the plating layer adhesive force is high, thegood balance point between the economical efficiency of the material and the adding amount of the vanadium, the aluminum, the copper, the nickel and the chromium are considered at the same time, and the content of the vanadium is 0.009%-0.019%.

Description

technical field [0001] The invention relates to a metal material processed fastener. Background technique [0002] In the prior art, stainless steel fasteners have good high temperature resistance and corrosion resistance, but after being strengthened by cold work hardening, the toughness is poor. In addition, nickel and chromium dense oxide crystal layers will be formed on the surface of stainless steel fasteners, which cannot The surface coating is formed by infiltrating surface alloys, which causes electrochemical corrosion when stainless steel fasteners are connected with other metal material components, especially when connecting with more active metal material components such as aluminum alloy, which will lead to these more active components. The amount of electrochemical corrosion of metal material components is relatively large; when carbon steel is strengthened by cold work hardening or quenched and tempered, it will crack and break when it is bent by punching, and ...

AI Technical Summary

Problems solved by technology

[0002] In the prior art, stainless steel fasteners have good high temperature resistance and corrosion resistance, but after being strengthened by cold work hardening, the toughness is poor. In addition, nickel and chromium dense oxide crystal layers will be formed on the surface of stainless steel fasteners, which cannot The surface coating is formed by infiltrating surface alloys, which causes electrochemical corrosion when stainless steel fasteners are connected with other metal material components, especially when connecting with more active metal material components such as aluminum alloy, which will lead to these more active components. The amount of electrochemical corrosion of metal material components is relatively large; when carbon steel is strengthened by cold work hardening or quenched and tempered, it will crack and break when it is bent by punching, and the corrosion resistance of carbon steel is poor, although the surface of carbon steel can be Surface treatment such as galvanizing, aluminum plating, copper plating, etc., however, the corrosion resistance life of these coatings is short, and the adhesion of the coating is poor

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