An Overview of Sensitization Dynamics in Ferritic Stainless Steel Welds

Abstract

Besides the problem of low ductility and poor notch toughness of ferritic stainless steel welds due to the microstructure characteristics of the weld section as a result of the weld heat input rate and the heat transfer factor, susceptibility to intergranular corrosion caused by the depletion of the chromium content of the weld matrix particularly in the HAZ is a major concern limiting the full deployment of the material in certain engineering applications regardless of its attractive economics combined with moderate strength and excellent corrosion resistance in alkali and acidic environments. Several attempts had been made to solve the problem. In the present work, a generic review of the sensitization problem in ferritic stainless steel welds as well as remediation techniques is presented. While stabilization is the most practiced prevention technique, it appears that the control of weld heat input and by extension the cooling rate is the ultimate option to prevent the onset of sensitization and control susceptibility to intergranular corrosion; however, the specific range of welding current and speeds that forms the given range of weld heat input needs to be determined.

Influence of filler wire composition on weld microstructures of a 444 ferritic stainless steel grade

“…Due to this transformation, Xinzhong et al (2008) observed some martensite in the HAZ of 430 grade. As explained by Greeff and Du Toit (2006) then Amuda and Mridha (2011), a sensitization mechanism could have also occurred in the HAZ of FSS even with stabilizing elements. Titanium or niobium carbides could be partially dissolved at high temperature that led to the precipitation of chromium carbides during rapid cooling.…”

Metalografska preiskava in korozijska odpornost zvarov feritnega nerjavnega jekla

“…8 [tudija korozijske odpornosti zvarov je izredno pomembna za uspe{no uporabo feritnih nerjavnih jekel. Poleg obna{anja samega materiala v korozijskem mediju, je pomembna tudi korozijska odpornost zvarnih spojev.…”

Investigations for Statistically Controlled Resistance Spot Welding Solution of Stainless Steel

“…Sensitization is a major problem in welding of SS that affects the alloys durability 1 . SS is commonly welded by resistance spot welding process process requires the application of both heat and pressure to achieve a sound joint.…”