DETERMINATION OF WORKABILITY CURVES USING 2 MECHANICAL TESTS

Manufacturing processes are concerned with producing parts with specif ic geometries, where the resulting properties are those imposed by sha pe changes and material interaction with the forming tools. The degree of shape change is limited by the capacity of the workpiece to deform plastically. Structural damage in metalworking limits the degree of s hape changes and reduces material utilization. Material utilization to its fullest potential - from the point of view of plastic flow and wo rkability potential - is highly desirable, particularly in an era of l imited resources. Although many of the elements required for an engine ering description of material failures under deformation are available , efforts in refining these elements and assembling them, particularly in uniting various inputs to offer parctical guidence in determining working limits, are still lacking. In this work, a simple approximate determination of workability limits has been carried out using only tw o mechanical tests: uniaxial compression and uniaxial tension. The two tests were chosen for their simplicity and because the corresponding state of stress for each test is clear. A linear relationship between the workability function (strain to fracture) and the stress formabili ty index is proposed, the equation of the proposed workability line be ing easy to formulate. The principle was applied to three kinds of ste el. The correlation is seen to be very good and the method is suggeste d as being very useful in pre-determining the amount of hydrostatic st ress needed to produce a successful component under particular working conditions.