Development of intermetallic-hardened abrasion-resistant weld hardfacing alloys.

摘要

Chromium and cobalt are strategic materials in the U.S. and both are major constituents in many weld hardfacing alloys. Substitution for these materials or alternatives to their use was a primary direction of this investigation which was conducted in conjunction with the U.S. Bureau of Mines. Minimization of the use of strategic materials was the criteria guiding the development of intermetallic-hardened abrasion resistant weld hardfacing materials. Other criteria were that the new alloy contain a hard intermetallic compound in an FCC matrix, and that these intermetallic compounds be stable at room temperature.A survey of ternary systems was made and the Fe-Mo-Ni system was selected to provide a basis for alloy development. Powder metallurgical techniques and arc-melting provided samples for initial examination. Further development was performed using the submerged-arc welding process with alloyed metal powder additions. Specimens were examined and wear resistance tested using the pin-on-drum abrasive wear test. Final compositions were also subjected to heat treatment and melting point analysis.Fe-Mo-Ni alloys synthesized by arc-melting and similar alloys made by welding possessed similar microstructures, a (Fe,Ni)