Laves phase embrittlement of the ferritic stainless steel type AISI 441

Evolution of the Laves Phase in Ferritic Heat-Resistant Steels During Long-term Annealing and its Influence on the High-Temperature Strength

“…[17] This steel does not contain the element W. Its application field is in automotive exhaust systems. [18] As can be seen from the calculated phase diagram in Figure 2, the solvus temperature of the Laves phase in steel X2CrTiNb18 is 1198.15 K (925°C) and that of alloy X1CrWNbTiLa22-2 is 1224.15 K (951°C). With demands for higher application temperatures up to 950°C, the stability of the Laves phase in these alloys is insufficient.…”

Relationship between Laves phase and the impact brittleness of P92 steel reevaluated

“…Although the area fraction of Laves phase exhibited a fairer correlation with absorbed energy, the results still showed some scattering. In another work [17] , the decreased volume fraction of Laves phase was corresponding to the increased impact toughness. Both the area fraction and the volume fraction are basically the combination of particle size and number density.…”

“…The effect of the morphology evolution of Laves phase on the impact toughness has been widely interpreted according to the following equation [16,17] :…”

“…Both the area fraction and the volume fraction are basically the combination of particle size and number density. It appears that either of these two morphological characteristics could be regarded as the key factor that controls the impact brittleness and this could be well interpreted by the traditional fracture theory [16,17] . These researches seem completed in both experimental and theoretical aspects.…”

The influence of thermomechanical processing on the surface quality of an AISI 436 ferritic stainless steel

“…Since new designs in the automotive industry are driven by safety and environmental concerns, the need to reduce the weight of the exhaust systems while maintaining good resistance to thermal fatigue is continuing to see the exploitation of the ferritic stainless steel family for alternative solutions. Ferritic stainless steels have a relatively low coefficient of thermal expansion and, therefore, some efforts have been made to create new ferritic stainless steels with high yield strengths at elevated temperatures, particularly by the addition of niobium (Nb), which increases the initial high-temperature strength through solid solution hardening (Sello and Stumpf, 2010). The ferritic type AISI 436 is increasingly used for automotive trims, with a major application being for lug nuts or wheel nuts on trucks.…”