Subsequent, you should use this boundary problem and fix for Fourier's 2nd Law to obtain the internal temperature distribution. Assuming no inner warmth technology, the answer is ρ C p ( ∂ T ∂ t + v → ▽ T ) = k ▽ T displaystyle rho C_ p ( partial T over partial t + overrightarrow v bigtriangledown T)=kbigtriangledown T MIG welding is