It can be said that the hotter the arc the greater the penetration. The longer that arc is played on the base metal or previous deposit, the greater the penetration. Unlike joining alloys, hardfacing alloys strive to produce as little penetration as possible. Deeply penetrating arcs not desirable in hardfacing alloys. We want as much of the electrode chemistry to be deposited per layer as possible.
Dilution is the measurement used to describe the amount of penetration in terms of the base metal.
It is described in terms of a percentage of base material within the deposit. Now let's assume that what we have just described is the first layer. You can see that as the number of layers increases, the deposit becomes closer to the chemistry of the weld wire. There are many factors that affect penetration and dilution. Any thing that produces high heat per linear length will increase penetration and dilution.