In the ethylene production by heating hydrocarbon source in the Fire Heater Fumace at high temperature as shown in Figure 3-1(a). Their molecules are cracked into an ethylene monomer with a chemical structure of C2H4. The dissociation reaction will occur in the tube coil which is the nickel-base alloy grade 35Cr-45Ni-Nb. Meanwhile, the soot and coke are formed as the by-product obtained from the dissociation reaction because there was incomplete combustion in tube coil. A volume fraction of coke in the used tube effect to service life of the tube as shown in Figure 3-1 (c,d,e) compared with the new tube figure 3-1 (f). After long life service at high temperature the used tube contained high volume fraction of the soot and coke.