Análisis de la influencia del proceso de galvanizado en caliente en la resistencia a la fatiga de pernos SAE grado 5 utilizados en juntas a corte para torres de telecomunicaciones

Abstract

This experimental work was done to determine the influence of hot-dip galvanization processes to evaluate the fatigue resistance of SAE grade 5 screws, which are often used in the construction of telecommunication towers, as screws of this denomination do not come galvanized and the company that build this type of structures uses heat treatment in order to lengthen service life due to these reasons we propose the obtainment of variation in the number of cycles of the afore mentioned screws until their final fracture and to be able to give a failure criteria as use prevention and also to know the influence of screw assemblage with their thread in the plane of plate cutting. We proceeded to create a test mechanism to simulate the working conditions of the screws and to galvanize the screws in order to test them, subjecting them to cyclic strains and similar torque adjustments, maintaining the same test conditions in each case These tests showed a decline of the resistance in galvanized screws that do not have a threaded test section of 13% with respect to the screws that were not galvanized and did not have a threaded test section. The following test of screws with a threaded test section shows an extreme decrease of the resistance which surpasses 95% and is exceedingly harmful to the performance of any equipment or mechanism that uses screws in this fashion.