The aim of this paper is to make a theoretical and experimental study to evaluate the water jet influence on a metallic material used in oilfield manufacturing, using AWJ process. It was investigated how the scattering of the jet has influenced the width of the kerf and neighboring area. The metallic material is P275NL2 which is a low temperature quality steel alloy specially used in petrochemical industry. The experimental tests were made on the waterjet cutting machine model YCWJ-380-1520 using preestablish working conditions. Theoretical investigations were performed using CFD simulation with planar 2D fluid flow on the geometrical model. Graphical correlation was performed between theoretical outcomes given by CFD simulation and experimental results on the regarded material, overlapping on the theoretical searching for the cutting velocity and the hardening velocity limits nearby the kerf.

The aim of this paper is to make a research in order to analyze the modification of the microgeometry parameters of AWJ machined surfaces for a ductile material used in oilfield and petrochemical equipment. Experimental research was performed on waterjet cutting machine model YCWJ-380-1520 using pre-establish working conditions. The SURTRONIC 3+ device was used in order to measure the microgeometry characteristics of the machined surfaces. Experimental tests were performed regarding some values for: material thickness, working feed-rate and standoff distance. The obtained outcomes highlighted that there are three zones on cutting surfaces for thick material and only two zones for thin materials. There are a lot of profile parameters provided by the software and there were taken into account only the average roughness (Ra) and average waviness (Wa). For each of those two parameters were accomplished graphical representation for every working parameters in order to establish an analytical dependence between them. The outcomes which were obtained are polynomial four order equations of average roughness and waviness according to standoff distance. The analytical relations obtained give us the possibility to estimate the average roughness of the surfaces related to thickness, feed-rate and standoff distance.

This study has the main objective the flow modelling using CFD through active parts waterjet cutting machine, model YCWJ-380-1520. More precisely, the study of flow through the cutting head and estimate the erosion wear caused by abrasion of these parts. The active parts of cutting head are the body of head, high pressure nozzle with jewel and mixing tube made from wolfram carbide. On all these components has previously done measurement in order to create the geometrical model. The most wearing subjected parts water-jet machine are the water nozzle and mixing tube where the erosion wear is accelerated by the high velocity. In the first part of this study is presented the water flow model without regarding the abrasive inlet geometry, using Ansys FLOTRAN CFD. Has been considered three dimensions of water nozzle along with three dimensions of mixing tube in order to evaluate velocity variation at mixing tube outlet and how geometry influences outlet velocity. The second part of this paper is made using CFD software Ansys Fluent regarding a tridimensional geometry and a multiphasic flow. In the framework of flow model is established the abrasive particles velocity, difference of pressure inside tube, contour of streamlines, shear stress on the tube wall in order to accomplish the erosion rate during the process flow. It can be noticed that there are two main streamlines: first at the outlet of water nozzle and second from the inlet of abrasive material. Particles velocity is higher at the contact with water stream and lower at the end of cutting head because the difference of diameters between jewel and mixing tube. The maximum erosion rate is recorded where the shear stress are high values, that means to the interior wall of water nozzle and inlet of mixing tube. Pressure becomes high to the jewel of water nozzle and decreases in value toward at outlet of cutting head.