Influence of Steel Structure on Machinability by Abrasive Water Jet

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.

Structure and Properties of Cast Ti-Al-Si Alloys

“…The influence of HIP treatment on the wear behavior, ultimate compressive strength and hardness was negligible, even though this process visibly changed the morphology of the silicide phase. In the steel, such spheroidization of carbides decreases the hardness, as it practically applied in soft annealing process [ 32 ]. However, it can be highly expected that the change of the morphology of silicide particles to round ones will strongly affect the toughness and fatigue life due to minimization of the stress concentration at the edges of the silicide particles.…”

Recent Progress Trend on Abrasive Waterjet Cutting of Metallic Materials: A Review

“…In ductile materials, erosion can occur using two procedures, i.e., repeated plastic deformation and cutting action. In general, ductile erosion is applicable to metals and other similar materials that are capable of a significant plastic deformation process [12]. For the brittle materials erosion process, removal of material occurs through crack propagation and chipping, resulting in contact stresses caused during the impact of abrasive particles, which is then defined as the cracking method [13].…”

“…These are difficult-to-cut materials that possess drawbacks related to their high alloying content (i.e., chromium and nickel), low thermal conductivity, high ductility, and low machinability A number of studies in metal, composite, and natural materials discovered similar quality defects such as surface roughness, striation marks and kerf geometry inaccuracies . As shown in Figure 2a, aluminum alloy, which is a metallic material, has captured the highest value of twelve (12) research studies, whilst natural material, rock, has gained the least attention amongst these selected recent researches in AWJM application. As illustrated in Figure 2b, metal materials have received the highest attention, attaining 58% of the population of these selected latest studies in AWJM performance.…”

Simple Approach for Evaluation of Abrasive Mixing Efficiency for Abrasive Waterjet Rock Cutting

“…As shown in Equation 8, it is possible to demonstrate the relationship between the kinetic energy removal and the experimental results in consideration of the focus geometry, the AFR, and the WFR. This model can also be expressed by the pump pressure using Equation (1). Through this study, the mixing variables can be expressed comprehensively.…”

“…Abrasive waterjets are used to cut target materials using high-velocity abrasives by accelerating them with high-pressure and high-velocity water. Although such waterjets are mainly used for cutting metals and ceramics, their geotechnical applications such as rock cutting, excavation, asphalt resurfacing, pavement adhesion improvement, and road stripe removal have recently increased [1][2][3]. In particular, since the cutting force can be controlled, it is possible to demolish concrete without damaging the internal steel reinforcement [4,5].…”