Evaluation of the Possibility of Using 1.4462 and 1.4501 Steel as a Construction Material for Apparatus Operating at an Increased Temperature and with Corrosive Factors.

Karol Prałat,Justyna Ciemnicka,Marek Ochowiak,Artur Koper,Sylwia Włodarczak,Magdalena Matuszak,Andżelika Krupińska,Karolina Wójcicka

doi:10.3390/ma14144014

Abstract

The objective of this study was to determine the requirements for steels used as construction materials for chemical apparatus operating at an elevated temperature and to correlate them with the properties of the tested steels. The experimental part examined the influence of the annealing process on the structure and properties of X2CrNiMoN22-5-3 (1.4462) and X2CrNiMoCuWN25-7-4 (1.4501) steel. Heat treatment was carried out on the tested samples at a temperature of 600 °C and 800 °C. Changes were observed after the indicated time intervals of 250 and 500 h. In order to determine the differences between the initial state and after individual annealing stages, metallographic specimens were performed, the structure was analyzed using an optical microscope and the micro-hardness was measured using the Vickers method. Potentiostatic tests of the samples were carried out to assess the influence of thermal process parameters on the electrochemical properties of the passive layer. An increase in the hardness of the samples was observed with increasing temperature and annealing time, the disappearance of magnetic properties for both samples after annealing at the temperature of 800 °C, as well as a significant deterioration in corrosion resistance in the case of treatment at a higher temperature.

Highlights

Fulfillment-determined emission standards are one of the basic aims, and the problems, e.g., for large industrial plants [1,2]
Solutions are being sought to optimize the operation of the generated exhaust gas cleaning systems
Besides the appropriate selection of the type of installation for a specific application, its operating parameters, and automation, the key stage is the selection of the construction material from which the apparatus is to be made [3]

Summary

Introduction

Fulfillment-determined emission standards are one of the basic aims, and the problems, e.g., for large industrial plants [1,2]. Solutions are being sought to optimize the operation of the generated exhaust gas cleaning systems. Boiler flue gas cleaning systems allow a reduction in sulfur compounds, and NOx , HF, HCl, heavy metals, and dioxins. Devices operating in such a system are exposed to an extremely aggressive, corrosive environment, as well as increased temperature. Another important problem related to the emission of pollutants into the air is the use of inadequate boilers [4]

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Conclusion