| Title |
Evaluation PTA Weld-Overlayers in Low Carbon Steel (2) ( Microstructural Evaluation of PTA Coated Layers on the Hardness , Wear Resistance , and Corrosion for the Hardfacing of 16C and Stellite 6 Alloys ) |
| Authors |
김형준(Hyung Jun Kim) ; 김용진(Yong J . Kim) |
| Abstract |
The microstructures of PTA (Plasma Transferred Arc) weld-overlayers were evaluated for those of open arc weldoverlayer and spray & fused coating. DSRW (Dry Sand Rubber Wheel) abrasive wear and potentiostatic corrosion tests in 3% NaCl solution were conducted. The Stellite 6 weld-overlayer by PTA method contains more eutectic and hence shows a little higher hardness than that by open arc method. The 16C weld-overlayer by PTA method contains coarser borides and carbides, but shows a little lower hardness than that by spray & fuse method. The borides and carbides in the spray & fused 16C coating are fine and more or less needle shape, and porosities are still present after fusing treatment. PTA weld-surfaced Stellite 6 overlayer shows twice more wear resistant than that of open arc method largely due to higher eutectic content. PTA weld-surfaced 16C overlayer also shows more wear resistant than that of spray & fuse method due to the size difference in borides and carbides. The results of potentiostatic corrosion tests indicate that both overlayers of PTA are superior to those of open arc and spray & fuse processes. |