Effect of Aging on the Microstructure and the Intergranular Corrosion Resistance of X2CrNiMoN25-7-4 Duplex Stainless Steel

Abstract

Stainless steels are used widely in many industries. A duplex microstructure offers a combination of advantages, including resistance to crevice and stress corrosion, reduced susceptibility to hot cracking in comparison with fully austenitic structures and excellent tensile strength. The paper discusses the effect of aging on the microstructure and corrosion resistance of X2CrNiMoN25-7-4 super duplex stainless steel. Low and predictable corrosion rate is an important parameter for steels operating in aggressive environments. Resistance to intergranular corrosion expressed by corrosion rate (mm/year) was determined in accordance with standard PN-EN ISO 3651-1. Metallographic studies were carried out to evaluate surface degradation and intergranular corrosion. The results support an evaluation of the impact that phase fraction changes caused by aging have on resistance to intergranular corrosion. The results of the corrosion analysis were used to develop mathematical models describing changes in corrosion rate over time for different phase fractions.

Metallographic Study and Repeatability Analysis of γ' Phase Precipitates in Cored, Thin-Walled Castings Made from IN713C Superalloy

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Corrosion of the 1.4362 Duplex Stainless Steel in a Nitric Acid Environment at 333 K

“…Stainless steel offers good resistance to homogeneous or local environmental attack. Particular corrosion-resistant steels are characterized by resistance only under specific conditions [1][2][3][4][5][6][7][8][9][10].…”

Institutional Aspects of Health and Safety at Work in Poland

“…Each work carries with it certain risk and hazard to life, or even the human life, but it should be maximally minimalized e.g. by use of more durable materials (Szabracki and Lipinski, 2014;Mazur and Mikova, 2016), properly designed devices (Ferdek and Kozien, 2013;Guzowski and Sobczyk, 2014;Krawczyk et al, 2018), a personal protection equipment or an appropriate organizational scheme of the company (Ulewicz, 2016;Pacana and Ulewicz, 2017;Maszke et al, 2018). There is social consent for certain risk connected with each kind of work because it is not possible to set up systems which would provide 100% security at work, but at some moment a border may appear, after crossing which, one could state that specific persons did not meet their obligations in securing safe and hygienic work conditions.…”