The Research On Mechanical Properties Of Powder Metallurgy Low Alloy Steels

According to the water atomized iron powder AHC100.29producted by Hoganas metal powder company, through the pre-mix way to add Mn, Mo, Cu, Ni four kinds of metal elements. And to Astaloy85Mo pre-alloy powder as raw material contrast alloy addition methods on iron base sintered product performance. Analysis the alloy microstructure and properties of alloy composition of different composition, in order to choose the best alloy composition.The results show that, in order to ferromanganese iron to add the Mn element, when the Mn content is0.5%, the pearlite plate distance is smaller, then the optimal material play better mechanical properties. Adding Mo powder through pre-mixing method, Fe-2Ni-0.5Mo-0.5Mn-0.8C optimal mechanical properties, tensile strength and flexural strength of527MPa and1097MPa. In order to advance alloy adding element Mo, Fe-2Ni-0.85Mo-0.8C tensile strength and flexural strength of648MPa and1461MPa. The microstructure of pre-alloyed sample is more homogeneous than the pre-mixed one, the tensile strength and flexural strength increased27.2%and41.4%to the premixed sample.Adding Cu and Ni is in favor of the pearlite transformation for the iron-based materials, and emerge martensitic phase is observed when Cu powder is added at3.5%. Ni addition is found to favor the densification process, while Cu results in an opposite impact instead. We also demonstrate that the mechanical properties of iron-based products can be enhanced with Ni and certain amount of Cu added. When Cu is added at3.5%, the mechanical properties decreases with increased Ni addition. Ni can promote sintering process when added3.5%Cu. Ni can promote the material size shrinkage during sintering process, while Cu leads to an increase in the material sintering dimension expansion. Fe-6Ni-2.5Cu-0.8C optimal mechanical properties, tensile strength and flexural strength of577MPa and1188MPa. In summary, the iron-based products with Ni and Cu content of6%and2.5%give an optimized overall properties and dimensional accuracy. The carburizing samples of Fe-2Ni-1.5Cu-0.8C play the smallest friction coefficient and the best wear resistance in the friction experiments.