Jozef Jurko

Accompanying phenomena in the cutting zone machinability during turning of stainless steels

The rapid development of industry is marked by the development and application of new materials with characteristics that broaden their applicable uses. Therefore, it is natural that advances in machinability attract a considerable interest even today. Precise and reliable information on the machinability of a material before it enters the machining process is a necessity and hypotheses must be tested through verification of actual methods. This article presents conclusions of machinability tests on austenitic stainless steels 1.4301 and describes appropriate parameters for the cutting zone during the process of turning. The article focuses on the analysis of selected domains through four basic some parameters of steel machinability.

Verification of Cutting Zone Machinability during the Turning of a New Austenitic Stainless Steel

In this study presents the conclusions of machinability tests on a new austenitic stainless steel X5Cr18Ni9MoTiN, which applicated in food processing industry, and describes important concurrent parameters for the cutting zone during the process of turning. The machinability of stainless steels is examined based on the cutting tests, cutting speed presented by v c-T diagrams. The effect of cutting speed are analysed by chip formation and tool wear mechanisms. Based on the cutting tests, cutting speeds of 40 to 200 m/min, feed rate of 0.04 to 1.2 mm and solid carbide indexable insert CNMG 120404-MF. Tool wear criterion, VB K value of 0.3 mm. Chip were analysed by Semi Electron Microscopy (SEM).

Verification of cutting zone machinability during drilling of austenitic stainless steels

Automated production of, in the sense of, machine production has characteristic features: a reduction of production costs, stimulation of the development of cutting tools, and changes in the construction of machine tools, all of which work against the creation of optimal technological methods, which thrusts the technological process of cutting into a more important position. These trends confirm that the cutting process remains one of the basic manufacturing technologies. A condition of the economic usage of modern, automated programmed drilling machines is the optimal course of the cutting process, i.e. the use of optimal work conditions. A summary of optimal work conditions requires knowledge of the laws of cutting theory and knowledge of the practical conditions of their application. This article presents the results of experiments that concerned the verification of machinability of work pieces of difference types of X12CrNi 18 8 austenitic stainless steel. Steel X12CrNi 18 8 is the chief representative of the austenitic stainless steels, and this steel falls into the category of materials that are difficult to machine. The rapid development of industry is marked by the development and application of new materials with characteristics that broaden their applicable uses. Precise and reliable information on the machinability of a material before it enters the machining process is a necessity, and hypotheses must be tested through verification of actual methods. This article presents conclusions of machinability tests on austenitic stainless steels and describes appropriate parameters for the cutting zone during the process of drilling with the goal of proposing recommendations for this steels, and to integrate current knowledge in this field with drilling and praxis. This article concerns itself with the evaluation of selected domains of machinability in compliance with EN ISO standards. The experiments were performed in laboratory conditions and verified in real conditions during manufacture. The set-up used contained the following components: a turning machine with gas regulation of rotational frequency, a cutting tool with M20 cutter.

The Use of TiAlN Coated Carbide Tool when Finish Drilling of Stainless Steel X4Cr17Ni8TiN

In this paper presents the conclusions of machinability tests on a new stainless steel X4Cr17Ni8TiN, which applicated in food processing industry, and describes important concurrent parameters for the cutting zone during the process of finish drilling. This paper presents the results of experiments that concerned the verification of temperature fields in tool and the machined surface by drilling of stainless steels X4Cr17Ni8TiN. The content of this paper also focuses on the analysis of selected domains through basic indicators of steel machinability: cutting edge tool life, surface roughness, and wear mechanisms. The machinability of stainless steels is examined based on the cutting tests. The effect of cutting speed are analysed by tool wear mechanisms, and temperature tool. Based on the cutting tests, cutting speeds of 40 to 80 m/min, feed rate of 0.04 to 0.1 mm per rev.and solid a new design of screw drill from sintered carbide with hydraulic holder. Diameter of screw drill is 5.5 mm. Tool wear criterion of VBK value 0.12 mm. Wear mechanisms analysed by Semi Electron Microscopy (SEM).

Vibration and Experimental Comparison of Machining Process

Abrasive water jet technology is among the unconventional ways of machining. In todays modern and progressive era is often used for cutting and machining of various types of materials because of lower costs and environmental impact, as the cutting tool is water, in our case, with the addition of abrasives. Objective of the measurements was to evaluate the impact of vibration on the technological head in abrasive water jet technology in changing the selected technological parameters and the flow rate of technological head. In the given experiment, the used material - steel Hardox 500 with a thickness of 10 mm. The effort was to investigate the effects of changes in the speed rate of technological head (by speeds - 40, 200, 400 mm / min) on the size of the vibration acceleration amplitude and its frequency. Based on the measured values of vibration to the technological head create the database and from it is evaluated the data in selected softwares (LabVIEW, SignalExpress and Microsoft Excel). Findings and conclusions are formulated on the basis of graphical dependencies, envelopes frequency spectra and comparison chart of envelopes.

Part as an Object of Assembly

Abstract We deal with static prearranged couples in practice quite often. Constructers are using them a lot to improve rigidity of product. Some examples are mentioned in this article. The paper also discusses the models of kinematic couples in plane and models of kinematic couples in space. Spatial movable and non-movable couples are commented on as well. The article particularly focuses on application of statics in the assembly in spatial couples (movable, non-movable) for intentional allowance fix which leads to a non-problem assembly. With fix like this, it is possible to manufacture selected parts in series while assuring non-problem assembly.

Visualisation in Assembly

Abstract The article is aimed at visualisation types in assembly. Broad usage of artificial visualisation in assembly is held down mainly for economic reasons. One of the possible solutions is usage of the presented light visualisation method. This simple method of light visualisation is convenient when vibration orientation is not working properly and artificial visualisation is economically ineffective. Described principle of orientation is a technical solution of the author.

Theoretical Aspect of Assembly

Abstract Assembly plays a decisive role in global production in terms of its share in the total costs of the products assembled and in terms of the number of people working in the field. The author of (1) indicates that the percentage of the workers in assembly out of the total number of the workers in manufacturing in the U.S.A. ranged from 26.3% (bicycles) to 45.6% (automobiles), while the cost of the product assembly represented typically more than 50% of the total costs. Despite the above-mentioned importance of assembly in the industry, the discontinuous production processes have not been paid adequate attention until recently. It was sufficient to manufacture parts and then an operative reasonably and inexpensively assembled each product manually. The authors of this paper would like to emphasise “the method of a systemic approach” which focuses upon identifying the key activities to meet the objective. Harmonious interrelations of the activities are often a source of greater profit than in a system where some activities are of the top level while the others are neglected (2). The aim of this paper is to describe theoretical aspects of all the typical activities of the assembly system.

Specification of Problems Solutions

Two successive parts produced by the same equipment are never the same dimensions, because the production process reflects the impact of the following influences.

Evaluation of the Capability of Machine

This chapter describes the organization, application, planning and evaluation capabilities of machines [59, 60]. The aim is, through the coefficients of capability c m and c mk, to determine the capability of a machine.