Analysis of Failure of Plug Used for Piercing of High Alloy Steel Tube

Described are the commonly-encountered types of failure of the plug as used for piercing of hialloy steel tube. Metallographic analysis and chemical composition analysis of the plug fracture are conducted with SEM and other optical methods and X ray fluorescence spectroscopic method respectively to identify the main causes responsible for the said failure. Based on the result,cast quality of the plug is improved by means of adjusting the contents of elements like Nb,Co and W,having led to the increase of the service span of the plug.