(b) What will happen if steel is kept in a heated condition too long?
(c) Why should a change be in evidence under these conditions?
32. (a) Explain what is meant by a “dished” patch, for boiler or thin armor plate?
(b) Draw such a patch.
(c) How is a patch of this nature prepared?
33. (a) What is meant by a “corrugated” patch for boiler or thin armor plate?
(b) Sketch such a patch.
(c) How is this kind of a patch prepared?
34. (a) What advantages has a “corrugated” patch over one that is “dished”?
(b) Where are “corrugated” patches used extensively?