Investigation of electrocontact annealing in the production process of steel welding wire

Abstract

The possibility of replacing the technological operation of direct heating in the furnace used in the process of production of steel welding wire for performing electrocontact heating to improve the quality of performed operations and improve the characteristics of the wire is considered. An experimental unit with a special arrangement of the electrocontact rollers with respect to the wire with the possibility of cooling is developed. Using the experimental unit of electrocontact heating, the mechanical parameters of the copper-plate welding wire are obtained for the technological route for production of wire with a diameter of 1.6 mm:

– ultimate strength – 770÷850 N/mm²;

– elongation – 5÷10 %.

For the production of wire diameters of 1.2 mm:

– ultimate strength – 700÷770 N/mm²;

– elongation – 5÷10 %.

These values satisfy the conditions for further wire processing and correspond to the requirements for the finished product.

The effect of direct current heating on the formation of the structure and the change in the mechanical properties of the welding wire СВ08Г2С is shown, namely, it provides the necessary strength of the wire and prevents the formation of «work hardening». Work hardening causes the wire to break when the drawing mill is working. The use of automatic temperature control by adjusting the supply of current for heating the wire has made it possible to ensure homogeneity of the internal structure of the wire and to reduce the number of breaks by 80 %.