signature=847f6cfe2ce8cd5edf33f69cc84d52f5,Analysis of technological parameters through response sur...

摘要：

This experimental study is an attempt to model technological parameters such as cutting forces and surface roughness in hard turning of X38CrMoV5-1 hot work tool steel hardened to 50 HRC. This steel is free from tungsten on Cr-Mo-V basis, insensitive to temperature changes and has a high wear resistance. It is employed for the manufacture of helicopter rotor blades and forging dies. The workpiece is machined by a whisker ceramic tool (insert CC670 of chemical composition 75%[Al.sub.2][O.sub.3]+25%SiC) under dry conditions. Based on [3.sup.3] full factorial design, a total of 27 tests are carried out. The range of each parameter is set at three different levels, namely low, medium and high. Mathematical models were deduced by applying analysis of variance (ANOVA) and through factor interaction graphs in the response surface methodology (RSM) in order to express the influence degree of each cutting regime element on cutting force components and surface roughness criteria. The results indicate that the depth of cut is the dominant factor affecting cutting force components. The feed rate influences tangential cutting force more than radial and axial forces. The cutting speed affects radial force more than tangential and axial forces. The results also reveal that feed rate is the dominant factor affecting surface roughness, followed by cutting speed. As for the depth of cut, its effect is not very important. These mathematical models would be helpful in selecting cutting variables for optimization of hard cutting process. Key words: hard turning, whisker ceramic, X38CrMoV5-1, cutting force, surface roughness, ANOVA, RSM. Kaesolevas eksperimentaalses uurimuses on modelleeritud loiketootluse peamisi parameetreid (loikejou komponendid ja pinnakareduse parameetrid) kovaduseni 50 HRC karastatud kuumstantsiterase X38CrMoV5-1 treimisel. Kulumiskindel Cr-Mo-V tooriistateras on volframivaba, ei ole tundlik temperatuurimuutustele ja leiab kasutamist helikopteritiivikute ning stantside valmistamisel. Kuumstantsiterast treiti monokristallidega armeeritud [Al.sub.2][O.sub.3] baasil keraamiliste (75% [Al.sub.2][O.sub.3] + 25% SiC) loiketeradega jahutusvedelikku kasutamata. Eksperimentide kavandamisel kasutati taisfaktoriaalset planeerimismeetodit. Kokku tehti 27 katset iga uuritava faktori (loikekiirus, ettenihkekiirus, loikesugavus) kolmel erineval tasandil. Analuusiti eelnimetatud tehnoloogiliste faktorite moju loikejou kolmele komponendile ja pinnakaredust iseloomustavatele parameetritele. Uurimistulemused naitasid, et domineeriva mojuga loikejou komponentidele on loikesugavus. Ettenihkekiirus on suurima mojuga loikejou tangentsiaalkomponendile, vaiksem radiaal- ja aksiaalkomponendile. Loikekiiruse moju on suurim loikejou radiaalkomponendile, vaiksem tangentsiaal- ja aksiaalkomponendile. Tulemused naitavad samuti, et pinnakaredust mojutab koige rohkem ettenihkekiirus. Vahim moju on loikesugavusel. Uurimistoo tulemusena saadud matemaatilised mudelid on abiks loiketootlusparameetrite valikul suure kovadusega tooriistateraste treimisel rasketes loiketingimustes.

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