A laser beam is an important energy source in surface processing in modern industry. A medium carbon steel cylindrical component was subjected to constant wear on its internal surface, e.g. a piston in a cylinder in a combustion engine. Based on a laser beam processing rig, you are required to design a process that can be used to harden the internal surface and increase the case depth of the cylindrical component, so that its service life can be prolonged, without extra mechanical machining being required after the treatment. Define the three key parameters that affect the laser beam surface processing, and describe how to adjust each parameter of the laser beam during the laser surface processing, in order to achieve a revised component with extended service life and no dimensional distortion.