Abstract
Surface hardening of AISI 440C martensitic stainless steel was achieved by laser transformation hardening (LTH) using a high-power CW Nd:YAG laser. A hardened layer of a few 100 μm thick, composed of martensite, retained austenite and fine carbides was formed. The microstructure and hardness of the laser-treated layer were dependent on the laser processing parameters, with the hardness values reaching the range 600-800 HV. Compared with conventionally heat-treated samples, the laser-treated samples contained more retained austenite and finer carbides due to a higher degree of carbide dissolution. The cavitation erosion resistance of AISI 440C was significantly improved after laser treatment, and was approximately three-fold higher compared with that achieved by conventional heat treatment. The high erosion resistance was attributable to a desirable microstructure, which exhibited a favorable combination of hardness and toughness, and contained fewer weak sites for erosion attack.
| Original language | English |
|---|---|
| Pages (from-to) | 96-104 |
| Number of pages | 9 |
| Journal | Surface and Coatings Technology |
| Volume | 173 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 1 Aug 2003 |
Keywords
- AISI 440C stainless steel
- Cavitation erosion
- Laser transformation hardening
- Retained austenite
ASJC Scopus subject areas
- Surfaces, Coatings and Films
- Condensed Matter Physics
- Surfaces and Interfaces