| 摘要 |
<p>A method of providing a weld overlay structure (10) on a heat transfer tube (12) or a membrane surface. A first continuous bead portion (26, 40) of an overlay material is applied onto the heat transfer tube or membrane surface by using a weld head to melt the overlay material. A second continuous bead portion (26', 40') of the overlay material is applied onto the heat transfer tube or membrane surface by using a weld head to melt the overlay material, in which the second bead portion partially overlaps with the first bead portion, forming a groove (30) between the first bead portion and the second bead portion. A third continuous bead portion (32, 42) of an overlay material is applied onto the heat transfer tube or membrane surface by using a weld head to melt the overlay material into the groove (30) between the first bead portion and the second bead portion, so as to form a relatively smooth surface.</p> |
