Effect of deformation route on the development of low CN Fe-20%Cr alloy by Equal Channel Angular Pressing

The effect of deformation routes on the microstructure, mechanical, and electrochemical properties of low CN Fe-20%Cr alloys by equal channel angular pressing (ECAP) has been investigated in detail focusing on the anisotropy of the microstructure. This alloy is pressed at 423K up to eight passes via the so-called routes A, Bc and C. The continuous refinement of the microstructure is sustained by ECAP until the sub-grain range. However, the degree of anisotropy of microstructural development was different among the three deformation routes. Materials processed by Route Bc exhibited a comparable micro-hardness value in three orthogonal planes than those processed by routes A and C. Pitting corrosion characteristics of the ECAP processed sample were investigated using an electrochemical potentiodynamic test. The increased pitting potential along with an increased number passes of ECAP were explained by enhanced protective passive layer of ultrafine grain structure, as compared to the coarse grain counterpart.