Účinné obrábění austenitických ocelí cermetovými výstružníky

On the effective reaming of austenitic steels with cermet reamers and flood cooling

článek ve sborníku ve WoS nebo Scopus

en

Reaming operation is a common technological process which enlarges a pre-existing hole. For austenitic steels, IT 5-6 and roughness bellow Ra 0.8 um are achieved today by cermet and diamond cutting tools operating with cutting speeds about 100 m/min. However, a high productive reaming relies upon good cutting material and coating, its design, cutting performance, correct alignment of a pre-drilled hole and powerful process cooling. In this operation, specific cutting forces can be found with effect on cutting performance and quality of the machined surfaces. Since little material is removed, reaming operation can be split into several time-phases of cutting with different cutting and tribological phenomena. This paper deals with a effective use of a solid carbide drill, a semi-finishing carbide boring head and powerful cermet reamers for CNC machining of stainless steel DIN 1.4404, X2CrNiMo1732 (equivalent standard AISI 316L). Kistler dynamometer 9272, charge amplifiers 9011 and the Dynoware program for total force loading of the samples were used. A new 5-axis machining centre MCV 1210 (ZPS-TAJMAC, share company, Zlin) controlled with Sinumerik 840D, thermogrips Bilz, HAM-FINAL cermet reamers and holders, and a special precise fixture for workpiece preventing its deflection was used. The Fuchs Oil emulsion (10% concentration, 60 bars in pressure, flood intensity 50 l/min) and outer system of cooling for the monolithic cermet reamers were used. The Taylor Hobson Form Talysurf PGI 400 profiler and measuring probe Renishaw OMP400 with SW Productivity+ were used for surface quality evaluation. Some works dealing with high dimensional accuracy, roundness and cylindricity measurements are still in progress. Selected variables like specific energy of reaming, coefficient of flank friction of the guide pads and other physical and technological variables are statistically assessed.

Vystružování je technologická operace rozšiřující předzhotovenou díru. U austenitických ocelí lze dosáhnout přesnosti IT 5-6 a drsnosti pod Ra 0,8um s cermetovými a diamantovými nástroji při řezné rychlosti 100 m/min. Tato práce se zabývá CNC obráběním austenitické oceli DIN 1.4404, X2CrNiMo1732 (AISI 316L). Dále byl použit dynamometr Kistler 9272, nábojové zesilovače 9011, SW Dynoware pro měření zatížení vzorků, 5-osé centrum MCV 1210 (ZPS-TAJMAC, a.s. Zlin) řízené Sinumerikem 840D, thermoupínače Bilz a výstružníky HAM-FINAL. Emulze Fuchs Oil (10% 60 barů, 50 l/min) vnější chlazení, Taylor Hobson Form Talysurf PGI 400 profilometr a sonda Renishaw OMP400 SW Productivity+ . Vyhodnocovány byly kruhovitost a válcovitost děr, drsnost povrchu, měrná energie vystružování, součinitel tření. Technologii lze doporučit pro podobné aplikace.

Reaming operation is a common technological process which enlarges a pre-existing hole. For austenitic steels, IT 5-6 and roughness bellow Ra 0.8 um are achieved today by cermet and diamond cutting tools operating with cutting speeds about 100 m/min. However, a high productive reaming relies upon good cutting material and coating, its design, cutting performance, correct alignment of a pre-drilled hole and powerful process cooling. In this operation, specific cutting forces can be found with effect on cutting performance and quality of the machined surfaces. Since little material is removed, reaming operation can be split into several time-phases of cutting with different cutting and tribological phenomena. This paper deals with a effective use of a solid carbide drill, a semi-finishing carbide boring head and powerful cermet reamers for CNC machining of stainless steel DIN 1.4404, X2CrNiMo1732 (equivalent standard AISI 316L). Kistler dynamometer 9272, charge amplifiers 9011 and the Dynoware program for total force loading of the samples were used. A new 5-axis machining centre MCV 1210 (ZPS-TAJMAC, share company, Zlin) controlled with Sinumerik 840D, thermogrips Bilz, HAM-FINAL cermet reamers and holders, and a special precise fixture for workpiece preventing its deflection was used. The Fuchs Oil emulsion (10% concentration, 60 bars in pressure, flood intensity 50 l/min) and outer system of cooling for the monolithic cermet reamers were used. The Taylor Hobson Form Talysurf PGI 400 profiler and measuring probe Renishaw OMP400 with SW Productivity+ were used for surface quality evaluation. Some works dealing with high dimensional accuracy, roundness and cylindricity measurements are still in progress. Selected variables like specific energy of reaming, coefficient of flank friction of the guide pads and other physical and technological variables are statistically assessed.

výstružník, austenit, cermet

reamer, austenite, cermet

2011

03.05.2011

The Swedish Production Academy

Lund

978-91-86401-05-4

Proceedings of the SPS 11

1

228–234

7