Properties of P/M Hipped Stainless Steel.

摘要

Mechanical properties and corrosion resistance is largely dependent on chemical composition and microstructure. Gas atomized and hipped material has some difference in chemical composition and different microstructure compared to cast and forged/rolled material. Producing components from hipped powder allows for the excellent properties of duplex stainless steels to be used in an increasing number of critical applications. Powder metallurgical processing provides a manufacturing route that improves workability, reduces segregation, and enhances properties. It also allows for near-net shape processing, which reduces the weight of material needed, making duplex stainless more competitive on a total cost basis. Near net-shape processing is also beneficial in that one can potentially bypass many costly or detrimental processing steps. This paper presents the initial results of a characterization of the properties of a variety of duplex grades. The alloys characterized include lean duplex, standard duplex and super duplex alloys. Where possible, it compares the results of mechanical and corrosion property testing of PMproduced duplex alloys to conventionally produced (cast or forged/rolled) duplex alloys of nominally the same composition. It is shown that the hipped properties are isotropic and are equal to or better than the best directional properties in the cast or forged/rolled materials. It is also shown that the ability to form near-net shapes allows for potentially detrimental processes, such as welding, to be avoided in many applications.