Carbonizing doesn't have anything to with a carb on a pipe.
Carbonizing (or blackening) is a breaking in process where the pipe is
prepared for a long life of smoking.
Taken from smokingpipes.com:
"At the end of each smoke, your pipe should be given a good cleaning.
Allow the pipe to cool, and then stir up any ash and dottle left in the
bottom of the bowl. Placing one finger or the palm of your hand over
the top of the bowl, shake the pipe for a few seconds to evenly
distribute the ash along the inside walls of the bowl, which will
greatly speed the formation of 'cake', a protective layer of carbonized
and ash inside your pipe. Cake acts as an insulator, greatly
extending the life of your pipe and guards against burn outs."
Sometimes people will use honey in the bowl to accelerate the
carbonizing process. Once you have a nice cake formed, you
shouldn't have to worry about burning your pipe. Also, whatever
you plan to smoke will be dried up plant material (tobacco, marijuana
etc) and it will burn much more easily than the wood of the pipe.
I know several people who smoke from wooden pipes, and only one of them
has ever burned their pipe, and that was after several years of