Warm forming of acid resistant steel wires used for manufacturing of springs

Acid resistant steel wires used for manufacturing of springs are required to show high strength properties, and especially very high fatigue strength while maintaining good plastic properties. The production of such wire is technologically difficult. The objective of the paper is to present the results of extensive laboratory and industrial research concerning the search for new conditions of producing wires used for manufacturing of springs. The self-annealing effect occurring in steel at large values of total deformation as well as forming at elevated temperature (warm forming) were employed in the investigations. The process of drawing final wires of 2.06–1.81 mm diameter range of AISI 302 acid resistant steel was realised according to large number of variants applying various reductions and temperature conditions. The wires obtained were used for manufacturing of different types of springs which afterwards were subjected to mechanical and fatigue testing. Additionally, the springs were subjected to special heat treatment. The results of investigations will allow the development of the new technology of production of acid resistant steel wires to be used for manufacturing of springs showing high life and high fatigue strength.