Microstructural, mechanical and intergranular corrosion behavior of cold work and thermal ageing of low nickel austenitic stainless steel

2019 ◽  
Vol 6 (5) ◽  
pp. 056508 ◽  
Author(s):  
Ankur V Bansod ◽  
Sourabh Shukla ◽  
Awanikumar P Patil
CORROSION ◽  
10.5006/3778 ◽  
2021 ◽  
Author(s):  
sourabh shukla ◽  
Awanikumar Patil ◽  
Ankur Bansod

The surface phase constituent of high-manganese austenitic stainless steel after cold work (15%, 30%, and 50%) and thermal aging at 900°C for 30 min. and 6 hrs, was characterized using X-Ray diffraction spectrum. The microstructural analysis was conducted using an optical microscope, a scanning electron microscope, and the electron back scattered diffraction technique. The double-loop electrochemical potentiokinetic reactivation test was used to measure the Intergranular corrosion resistance (degrees of sensitization). The results showed that fine-recovered grains of austenite and strain-induced martensite together formed the surface of high-manganese steel after cold work. Because of the formation of strain-induced martensite in the cold work samples, their Intergranular corrosion were much higher than that of the as-received sample. Besides, the degree of sensitization of 15% cold work was higher (i.e., more intergranular corrosion) compared to the degrees of sensitization of 30% and 50% cold work. On the contrary, the intergranular corrosion of high-manganese austenitic stainless steel sample subjected to cold work was eliminated during thermal aging at 900°C for six hours because of the reversion of strain-induced martensite and fine-reverted austenite grains. Owing to this grain refinement of austenite, faster diffusion rate of Cr at higher temperature and cold work helped healing of Cr-depletion zone in a shorter time. In other words, because the results showed that on 50% cold work and thermal aging at 900°C for six hours, the high-manganese austenitic stainless steel does not become susceptible to intergranular corrosion. Hence, it could be beneficial to investigate the intergranular corrosion of high-manganese austenitic stainless steel.


2019 ◽  
Vol 66 (6) ◽  
pp. 757-767
Author(s):  
Sourabh Shukla ◽  
Awanikumar P. Patil ◽  
Ankur Bansod

Purpose The purpose of this study is to investigate the effect of prior cold work after annealing and thermal ageing on intergranular corrosion or sensitization of Cr-Mn austenitic stainless steel (ASS) is necessary. Such a study is particularly important because ASS are mostly used and welded in mill-annealed condition, which is equivalent to fully annealed material with some cold worked (CW). Design/methodology/approach The effect of 15% CW of 202 ASS were investigated using microstructural (optical microscope), mechanical (grain size and hardness) and electrochemical methods (double loop electrochemical reactivation [DLEPR]) followed by thermal ageing (800°C, 900°C and 1000°C). Findings X-ray diffraction analysis shows the presence of martensite in CW samples. The increase in martensite formation (800°C and 900°C) can be observed with the variation of thermal ageing (TA) duration (1, 2 and 3 h). However, there was decreased in the formation of martensite at the temperature of 1000°C because of martensitic reversal. The DLEPR test result shows higher degree of sensitization (DOS) for 800°C and 900°C but for 1000°C, there was re-homogenization of samples which leads to lower DOS (thermal ageing for 1, 2 and 3 h). Originality/value For 300 series steel, there are various literature available for the effect of cold work on mechanical properties and DOS. However, no one has investigated the effect of cold work and thermal ageing on the sensitization of 202 Cr-Mn ASS.


Alloy Digest ◽  
2000 ◽  
Vol 49 (11) ◽  

Abstract Sandvik 5R75 is a molybdenum-containing austenitic stainless steel with titanium added to prevent intergranular corrosion by tying up the carbon. This datasheet provides information on composition, physical properties, hardness, and tensile properties as well as fracture toughness. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-777. Producer or source: Sandvik Steel Company. Originally published March 2000, corrected November 2000.


Alloy Digest ◽  
2001 ◽  
Vol 50 (4) ◽  

Abstract ALZ 321 is an austenitic stainless steel with good cold formability, corrosion resistance, toughness, and mechanical properties. The addition of titanium improves the resistance to intergranular corrosion in welds and slower cooling sections. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on forming, heat treating, and machining. Filing Code: SS-821. Producer or source: ALZ nv.


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