EFFECTS OF AIR-BLAST PRESSURE AND EXPOSURE TIME ON THE SHOT-PEENING PROCESS

Shot peening was carried out on 6061-T651 aluminium alloy. The effects of two main peening parameters, i.e. the air-blast pressure and the e xposure time, on the depth of the plastic zone and on the residual str ess of shot-peened plates were investigated and analysed, the experime ntal data showing that the depth to which yielding occurs is affected by the air-blast pressure as a power law, and that there is an exponen tial relationship between the depth to which yielding occurs and the e xposure time. For a given pressure the depth of yielding approached a limiting value after a certain exposure time. An empirical equation fo r the relationship of the depth of yielding with the pressure and the time has been derived from the test data. Further, it is found that th e maximum residual stress within the shot-peened plate is determined s olely by the depth of yielding, according to a simple equation. These two equations are convenient for industrial use.