Technological Tests of Metals

Technological Tests of Metals 

methods for determining the ability of metals to undergo deformation similar to that encountered during processing or use. Such tests include the sagging test, flattening, coiling of wire, testing roofing iron for making seams or scarf joints, bending, folding, and fashioning of shaped articles. Technological tests of metals are standardized in many countries, including the USSR.

Technological tests are sometimes called fabrication tests. In order to evaluate the quality of piping, for example, samples are tested for widening, flattening, and bending, for stretching and widening of ring sections, and for deformation under hydraulic pressure. A metal’s plasticity, or deformability, is determined in order to evaluate the ability of the metal to undergo plastic deformation without fracturing during specific types of pressure working. The plasticity is sometimes designated by the name of the specific process involved. For example, the stamping test, or Eri-chsen test, involves punch pressing a thin (up to 2 mm thick) plate between a die and an anvil; it is designed to determine the suitability of a metal for cold working and drawing.

Reliability is tested by longitudinal rolling of wedge-shaped samples or by rolling samples into wedges; it is used for an approximate determination of the maximum degree of deformation for a given material. Broachability is tested by screw milling of conical or cylindrical samples; it is used for an approximate determination (for a conical sample) or a more precise determination (for a cylindrical sample) of the maximum reduction in front of the tip of the mandrel in the broaching of stock.

R. M. GOLUBCHIK