What Does Low X-Factor Mean?
The Bruscato X-factor is a way to measure temper embrittlement resistance in applications where the weld metal deposit may be exposed to high temperatures over a long period of time. Certain residual elements (Phosphorus, Tin, Antimony, and Arsenic) migrate to grain boundaries over time in these high temperature conditions, causing a loss of toughness. This is known as temper embrittlement.
The X-factor is a numerical value that is calculated based on levels of residual elements in the weld deposit – lower x-factors represent lower levels of these tramp elements and higher resistance to temper embrittlement. Many customer specifications in the pressure vessel and petrochemical industry call for E8018-B2 or E9018-B3 electrodes with an X-factor of less than 15.