Investigation of breaks of the «Sparking» type of brass‑plated wire for metal cord and high‑pressure hoses and the causes of their formation

Abstract

The article examines the breaks of thin brass‑plated wire for metal cord and high‑pressure hoses of the “sparking” type and the causes of their formation. The wire was manufactured in OJSC “BSW” – he Management Company of the Holding” BMC “ in the conditions of steel‑wire workshops. The appearance and microstructure of breaks of thin brassplated wire of the “sparking” type are investigated. As a result of the analysis of the appearance and microstructure of the breaks, it was assumed that surface defects are formed on the brass‑plated wire – billet during the welding connection in the jaws of the welding machine during annealing. To confi m this, experiments were carried out with the implementation of welded joints of brass – plated wire‑blanks in wet drawing areas, the appearance and microstructure of the obtained samples of welded joints were studied.As a result of experiments and metallographic studies, the assumption was confirmed that local defects such as “cauterization from sparking” on the surface of the workpiece wire are formed during welding during the annealing operation, it was established that the cause is a violation of contact between the wire and the pressure jaws of the welding machine, wear of the pressure jaws. Photos of the defect, a description of its appearance and microstructure are given.Based on the obtained studies, a number of measures were carried out aimed at eliminating the causes of this defect.

Keywords

• thin brass – plated wire
• blank wire
• wire breakage
• surface defect
• “sparking” type
• cauterization from sparking
• stereoscopic microscope
• microstructure
• martensite
• weld
• welding machine sponges
• annealing
• wear