Influence of tempering treatment on microstructure and pitting corrosion of 13 wt.% Cr martensitic stainless steel

Effects of Low-Temperature Tempering on Microstructure and Properties of the Laser-Cladded AISI 420 Martensitic Stainless Steel Coating

“…Significantly, the as-tempered specimen exhibited striking tensile properties: UTS (ultimate tensile strength) of 1690 MPa, YS0.2 (0.2% yield strength) of Similarly, two types of granular carbides can be observed on the martensite matrix (Figure 5c,d,e). It can be noticed that the number density of Fe 3 C carbides increased after tempering, which is in good agreement with the formation of nano-sized M 3 C carbides after tempering in the temperature range of 150-350 • C, as reported by other studies [15,16]. The increased precipitation of Fe 3 C carbides in the as-tempered specimen can be explained by the decomposition of the supersaturated martensite matrix, due to the rapid solidification of the laser cladding process.…”

“…It is well-known that the element carbon can diffuse readily at 100-200 • C and segregate at lattice defects [3], consequently precipitate in the formation of carbides during the subsequent tempering process. Comparatively, the number density of M 23 C 6 particles almost remained the same, which was demonstrated to precipitate preferably at a higher tempering temperature above 500 • C in previous work [15][16][17][18].…”

Effect of Pre-passivation on the Corrosion Behavior of PH13-8Mo Stainless Steel in Industrial—Marine Atmospheric Environment

“…In PH13-8Mo stainless steel, there were a large amount of Cr-rich M 23 C 6 precipitates, which induced the emergence of the Cr-depleted zones around the precipitates (Luo et al, 2018), as shown in Figure 2. The surface passive film over the Cr-depleted regions was known to be weak and thus led to the preferential attack (Ryan et al, 2002;Bonagani et al, 2018) by the high concentration of the chloride ion in the industrial-marine atmosphere, which created a priority for the pitting nucleation. Therefore, both the chloride-containing environment and the Cr-rich precipitates played an important role in the initiation of the pitting corrosion.…”

Коррозионное растрескивание под напряжением металлов и сплавов в агрессивных H-=SUB=-2-=/SUB=-S-CO-=SUB=-2-=/SUB=--Cl-=SUP=---=/SUP=- средах

“…Наивысший объем остаточного аустенита достигается в результате двойного отжига при температурах 670 и 600 • C [35]. Обогащенные хромом карбиды стимулируют питтинговую коррозию за счет обеднения хрома в областях, примыкающих к карбидам [36]. В то же время с увеличением доли остаточного аустенита наблюдается более высокий питтинговый потенциал, низкая плотность тока в пассивной области и уменьшается плотность метастабильных питтингов [34,35].…”

“…В кислых средах с сероводородом образующиеся на поверхности 13%Cr сталей продукты коррозии в виде сульфидов металлов также оказывают заметное влияние на коррозионную стойкость. При низких концентрациях в растворе H 2 S может способствовать образованию сульфидных фаз; высокие концентрации H 2 S ускоряют анодное растворение и увеличивают склонность стали к точечной коррозии и SCC [36,37].…”