Determining the Sensitization of Stainless Steel Using Electrochemical Testing
Faculty Mentor Information
Dr. Mike Hurley, Boise State University
Presentation Date
7-2025
Abstract
Stainless steel is a metal alloy that often undergoes metallurgical phase changes based on the heat applied to the steel, and the amount of time the heat is applied. When a specific metallurgical phase of stainless steel is desired, the heating/cooling process can be very precise. Joining stainless steel parts through welding or brazing requires heat input. When brazing stainless steel parts together, the stainless steel may undergo metallurgical phase changes that alter the material’s performance. When the stainless steel is heated between 500C and 850C, atoms within the stainless steel begin to move, this is known as diffusion. Diffusion within stainless steel can cause chromium atoms to rearrange and react with carbon which is called sensitization. The chromium atoms bond with oxygen to form an oxide layer to protect the stainless steel from corrosion, but when these atoms diffuse, the oxide layer breaks down, and the material can become susceptible to corrosion. This research will use a potentiodynamic polarization scan to identify if sensitization has occurred on a stainless steel sample that has been subjected to a braze heat treatment process.
Determining the Sensitization of Stainless Steel Using Electrochemical Testing
Stainless steel is a metal alloy that often undergoes metallurgical phase changes based on the heat applied to the steel, and the amount of time the heat is applied. When a specific metallurgical phase of stainless steel is desired, the heating/cooling process can be very precise. Joining stainless steel parts through welding or brazing requires heat input. When brazing stainless steel parts together, the stainless steel may undergo metallurgical phase changes that alter the material’s performance. When the stainless steel is heated between 500C and 850C, atoms within the stainless steel begin to move, this is known as diffusion. Diffusion within stainless steel can cause chromium atoms to rearrange and react with carbon which is called sensitization. The chromium atoms bond with oxygen to form an oxide layer to protect the stainless steel from corrosion, but when these atoms diffuse, the oxide layer breaks down, and the material can become susceptible to corrosion. This research will use a potentiodynamic polarization scan to identify if sensitization has occurred on a stainless steel sample that has been subjected to a braze heat treatment process.