Iron-based shape memory alloy locking bolt as well as production and application method thereof

Abstract

The invention relates to an iron-based shape memory alloy locking bolt as well as a production and application method thereof. The iron-based shape memory alloy locking bolt is characterized by comprising 16.8-17.23% of Mn, 4.50-4.7% of Si, 2.23-10.30% of Cr, 2.26-5.29% of Ni, C equal to or less than 0.08% and Fe beside the impurities in mass percent. The production and application method comprises the steps of: treating a turned bolt bar which is made of an iron-based shape memory alloy at 1100DEG C for 60 minutes and then carrying out uniaxial tension; and combining the bolt bar with a common nut to form a screw thread pair through precisely controlling the pre-tightening force and then carrying out heating, heat preservation and cooling: the stage is the realization stage of shape memory effect of the bolt: through radial, axial and martensitic phase transformation and restoration, radial and axial restoration force is produced to realize locking. The iron-based shape memory alloy locking bolt is applicable to the occasions with dismounting difficulty, high-velocity motion and check difficulty in machines and capable of effectively solving the loose failure cracks of key thread connection in chain transmission, bridges and space flight and aviation equipment.

Description

technical field [0001] The invention belongs to threaded fasteners, in particular to an iron-based shape-memory alloy anti-loosening bolt for preventing thread pairs from loosening and loosening, as well as its manufacturing and application methods. The iron-based shape-memory alloy anti-loosening bolt is especially suitable for occasions where disassembly and assembly are difficult, high-speed movement, and internal inspection of the machine are difficult. Background technique [0002] As we all know, threaded connection is one of the commonly used connection methods for modern structures and mechanical equipment. Generally, threaded connections have self-locking properties, but when subjected to large vibrations, variable loads, impacts, or large temperature changes, threaded connections are prone to loosening and loosening, resulting in a decrease in pre-tightening force. The use practice, anti-loosening performance test and fatigue strength test of threaded connection p...

AI Technical Summary

Problems solved by technology

Such as ST2 type anti-loosening nuts, concave-convex type anti-loosening nuts, wedge self-locking nuts, keyed anti-loosening nuts, etc. Although these anti-loosening methods have achieved certain anti-loosening effects under certain working conditions, they still have limited anti-loosening performance. Not very reliable, or because it requires auxiliary parts and auxiliary processing brings inconvenience in use, or fundamentally changes the nature of the detachable connection, or is difficult to promote because of the high cost

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