Backing Gas Heat Capacity

Physicochemical mechanism of action

The purging gas heat capacity is the energy that the gas absorbs or releases per unit mass. Water vapor has a high heat capacity and can therefore absorb and release a lot of energy, leading to uniform cooling.

Metallurgical relevance & risks when welding

A low heat capacity value can lead to uneven cooling and hot cracking. High-quality purging gases such as water vapor prevent these problems by releasing energy evenly.

Workshop practice & instructions

Use purging gas with high heat capacity, such as water vapor, to ensure uniform cooling of the weld. This prevents hot cracking and increases the overall strength of the joint.