Title

EFFECT OF SENSITIZATION TREATMENT ON THE MICROSTRUCTURES AND PROPERTIES OF 204C2 AUSTENITIC STAINLESS STEELS

Authorship

SONG, RENBO; WANG, TIANYI; CAI, HENGJUN; WEN, JIAN; SU, YANG; GUO, KE

SONG, RENBO

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WANG, TIANYI

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CAI, HENGJUN

I am this author

WEN, JIAN

I am this author

SU, YANG

I am this author

GUO, KE

I am this author

DOI

10.5151/2594-5327-33541

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Abstract

Influence of different sensitization temperatures and times on 204C2 austenitic stainless steel was studied in this research. Mechanical properties for the experimental steels were studied by tensile and hardness test. The samples were sensitization-treated at three different times and four different temperatures. SEM and TEM were used to characterize the evolution of carbides and the chemical component was investigated using EDS. Results show that the strength and elongation decrease with the increase of sensitization temperature and time. Compared with the solid solution sample, the ultimate tensile strength, yield strength and elongation respectively decreased by 101MPa (11.1%), 86MPa (16.0%) and 8.6% (17.3%) at the 800℃. This is closely related to the precipitation of carbides. Carbide precipitation along the wider grain boundary (corrosion groove) is easy to be observed after sensitization treatment. Precipitate phases are mainly composed of chromium, manganese and carbon elements. The chromium-depleted zones appear around the precipitate phases. With the increase of sensitization time and temperature, the quantity and size of precipitates increase. The chromium in the chromium-depleted zones becomes lower levels and intergranular corrosion is more likely to occur when the sensitization time and temperature increase.

Keywords

204C2 Cr-Mn austenitic stainless steel; Microstructure and mechanical properties; Sensitization temp