Wire Arc Additive Manufacturing (WAAM) is a novel manufacturing technique that can directly fabricate fully dense large 3-D near-net shape components from metal wire. In this process, wire is fed at a controlled rate into an electric arc and is melted onto a substrate or the previously deposited layer. WAAM has a much higher deposition rate (several kg/h) than most other metal additive manufacture processes. It also has a higher material usage efficiency (approaching 100 pct), no powder handling requirement, and a lower cost compared with the laser and powder-based technologies. Typically, the cost of a part produced by the WAAM process is an order of magnitude less than the cost when produced by laser-based powder processes. In WAAM process, the workpiece experiences complex thermal process, being repeatedly heated at the same place, and the complex thermal process results in the complicated thermal stress evolution and residual stress distribution in the deposition of metal wire. There are many important process parameters in WAAM, including deposition power, deposition speed, deposition patterns, deposition directions, and inter-pass idle time. Duplex stainless steel (DSS) tubes are fabricated for various applications where strength and high corrosion resistance is needed. One such application is in heat exchangers where 2205 tubes are welded to 2205 tube sheets. The objective here is to produce seamless duplex stainless steel tubes/pipes using WAAM process such that the microstructure across the growth direction maintains the 50% austenite/50% ferrite phase. The mechanical/corrosion properties of DSS depend on amount these phases.
- Learn the versatility of the wire arc additive manufacturing (WAAM) method
- Understand its rapid processing
- Learn its economic benefits