<abstract xmlns="http://www.w3.org/1999/xhtml"><p>The paper presents the results of the investigation of microstructure of the welded X5CrNiCuNb16-4 (17-4PH) steel after solution treatment and aging at 620°C for different periods. The microstructure and the phase composition of the steel was investigated using light microscopy (LM), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), transmission electron microscopy (TEM) and the X-ray diffraction (XRD). Hardness was measured for samples aged at different times. Density distributions of Cu precipitates were established. The investigation has shown that the microstructure of the X5CrNiCuNb16-4 steel welds after aging at 620 ° C consists of tempered martensite, fine Cu precipitates and austenite. It was observed that the size of the Cu precipitates increases with increasing the aging time, what affects the decrease of hardness. Simultaneously, the quantity of reversed austenite increases with increase of aging time. It was revealed that enrichment of the austenite in Ni, Cu and C affects the increase of M<sub>s</sub>, but this factor does not determine the stability of austenite.</p></abstract>

The paper presents the results of the investigation of microstructure of the welded X5CrNiCuNb16-4 (17-4PH) steel after solution treatment and aging at 620°C for different periods. The microstructure and the phase composition of the steel was investigated using light microscopy (LM), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS), transmission electron microscopy (TEM) and the X-ray diffraction (XRD). Hardness was measured for samples aged at different times. Density distributions of Cu precipitates were established. The investigation has shown that the microstructure of the X5CrNiCuNb16-4 steel welds after aging at 620 ° C consists of tempered martensite, fine Cu precipitates and austenite. It was observed that the size of the Cu precipitates increases with increasing the aging time, what affects the decrease of hardness. Simultaneously, the quantity of reversed austenite increases with increase of aging time. It was revealed that enrichment of the austenite in Ni, Cu and C affects the increase of Ms, but this factor does not determine the stability of austenite.

Microstructure Characterization of Welds in X5CrNiCuNb16-4 Steel in Overaged Condition

AGH University of Science and Technology in Krakow

Faculty of Metals Engineering and Industrial Computer Science

Faculty of Mathematics, Physics and Technical Science, Institute of Technology

Advances in Materials Science

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

The paper presents the results of the investigation of microstructure of the welded X5CrNiCuNb16-4 (17-4PH) steel after solution treatment and aging at 620°C...

Microstructure Characterization of Welds in X5CrNiCuNb16-4 Steel in Overaged Condition

Published Online: Apr 15, 2019

Page range: 57 - 69

DOI: https://doi.org/10.2478/adms-2019-0005

Keywords
welds, 17-4PH steel, reversed austenite, martensitic PH stainless steels, aging

© 2019 A. Ziewiec et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Microstructure Characterization of Welds in X5CrNiCuNb16-4 Steel in Overaged Condition

Published Online: Apr 15, 2019

Page range: 57 - 69

DOI: https://doi.org/10.2478/adms-2019-0005

Keywordswelds, 17-4PH steel, reversed austenite, martensitic PH stainless steels, aging

© 2019 A. Ziewiec et al., published by Sciendo

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
welds, 17-4PH steel, reversed austenite, martensitic PH stainless steels, aging