Testing big hubs

Testing big hubs

Keywords: Indentec, Hardness testing

A special system from Indentec enables the hardnesses of large, heavy turbine hubs to be determined quickly and repeatedly with manual handling.

Designed for hubs up to 1,000mm in diameter and weighing 30kg and more, the system consists of a dual-scale digital tester fitted with a Y-frame table that can be adjusted to give stable, three-point support to each hub during testing.

Brinell tests are made on the hub at points near the firtree fixings for the turbine blades. When the point has been selected, the system positively locates the hub beneath the nose-mounted indenter.

After the test, the indenter is retracted so that the image of the impression can be transmitted by a fixed, high-resolution camera to a monitor, where the diameter is measured to establish the hardness. The reading is then downloaded to a printer along with related data.

The system uses Brinell testing – with a 1mm diameter ball and 30kgf test load – because the process minimizes the risk of significant stress points close to the firtree fixings.

However, it can also be employed for Vickers testing using a diamond indenter and registering the impression on the same monitor.

Details available from: Indentec Hardness Testing Machines Ltd. Tel: +44(0)1384 896949.