Influence of Steel Structure on Machinability by Abrasive Water Jet.

Irena M Hlaváčová,Petra Váňová,Marek Sadílek,Martin Tyč,Štefan Szumilo

doi:10.3390/ma13194424

Irena M Hlaváčová, Petra Váňová + Show 3 more

Open Access

https://doi.org/10.3390/ma13194424

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Journal: Materials	Publication Date: Oct 5, 2020
Citations: 18	License type: CC BY 4.0

Affiliation: Technical University of Ostrava

Abstract

Although the abrasive waterjet (AWJ) has been widely used for steel cutting for decades and there are hundreds of research papers or even books dealing with this technology, relatively little is known about the relation between the steel microstructure and the AWJ cutting efficiency. The steel microstructure can be significantly affected by heat treatment. Three different steel grades, carbon steel C45, micro-alloyed steel 37MnSi5 and low-alloy steel 30CrV9, were subjected to four different types of heat treatment: normalization annealing, soft annealing, quenching and quenching followed by tempering. Then, they were cut by an abrasive water jet, while identical cutting parameters were applied. The relations between the mechanical characteristics of heat-treated steels and the surface roughness parameters Ra, Rz and RSm were studied. A comparison of changes in the surface roughness parameters and Young modulus variation led to the conclusion that the modulus was not significantly responsible for the surface roughness. The changes of RSm did not prove any correlation to either the mechanical characteristics or the visible microstructure dimensions. The homogeneity of the steel microstructure appeared to be the most important factor for the cutting quality; the higher the difference in the hardness of the structural components in the inhomogeneous microstructure was, the higher were the roughness values. A more complex measurement and critical evaluation of the declination angle measurement compared to the surface roughness measurement are planned in future research.

Highlights

The technology of Abrasive waterjet (AWJ) has been widely used in many areas of human activity for several decades
Our research was aimed at testing the validity of the findings presented in [26] for other surface quality indicators than the declination angle, namely Ra and Rz, which are more generally applied in engineering
Yield strength—or, if these are not significant, proof strength Rp0.2 —ultimate tensile strength Rm and percentage elongation after fracture A). Another table provides the surface roughness parameters: the arithmetical mean deviation Ra, maximum height Rz and mean width RSm; all three lines are presented, without an average evaluation, because the interaction of the abrasive waterjet (AWJ) with the material traced on the bottom line is distorted by the pressure oscillations; the lines should be discussed individually

Summary

Introduction

The technology of Abrasive waterjet (AWJ) has been widely used in many areas of human activity for several decades. The physical principle of the process is the transfer of mechanical energy from the pump to material and its use for required operations, namely various types of material disintegration such as milling [1,2], machining of composites [3], rock breaking [4], wood cutting [5], and many others. One of the most frequent and important applications of this technology is material cutting. In the case of plain dividing cuts, the quality is usually not the most important thing. It may become the key problem in complex engineering processes

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