Maprom NCB Hard coated Liners
MAPROM NCB (Nickel-Chromium-Boron) hard coated liners are guaranteed to double the life of shafts made of conventional materials such as stainless- or carbon steel, but even 4 or 5 times longer shaft-life may be possible.
NCB liners with a 58 to 62 HRc (hardness) also increase service wear life of shafts and shaft sleeves where mechanical abrasion and corrosion takes place, like seals, packing, and bearing areas.
Maprom NCB Shaft Sleeves can provide maximum protection for rudder stock and tail shafts. The fused area of the shaft sleeve is undercut. The undercut area is then thermal coated with the Nickel-Chrome-Boron powder using multiple spraying passes, the sleeve is hard-coated to an oversized dimension. A heat treating process is used to fuse or metallurgically bond the NCB hard coating to the base material at a very high temperature. After cooling, the shaft sleeve is ground to a 6-8 RMS finish and provides a 58-62 HRc.