Performance Characteristics of a Newly Developed Cost-Effective Cr-Ni Prealloyed Steel Designed to replace Fe-Ni Steels

Many PM applications requiring very good heat treated properties have utilized the FN-020X material system due to the relative economy of the system and ease of use. Recently, however, increases and wide fluctuations in the price of nickel have made the FN material systems less attractive. The FN system has also been challenging to use in applications requiring tight dimensional tolerances due to inconsistencies in dimensions related to negative dimensional change and segregation of admixed nickel. Many of the Cr-based systems introduced in the last few years have lower total alloy cost and excellent properties, but require careful sintering and heat treatment. The purpose of this paper will be to demonstrate the properties achievable with a new prealloyed Cr-Ni steel (Astaloy CMN) that is suitable for sintering in endogas and for conventional atmosphere heat treatment. The heat treated properties of this new Cr-Ni prealloyed steel equal or exceed the FN-020X system while providing significantly lower total alloying cost. The focus of this paper is to present heat treated properties of test specimens sintered both in 90 v/oN2/10 v/oH2 and Endogas