Turgay Kıvak

Machinability of AISI 316 Austenitic Stainless Steel With Cryogenically Treated M35 High-Speed Steel Twist Drills

In this paper, machinability of AISI 316 austenitic stainless steel was investigated usingcryogenically treated and untreated high-speed steel (HSS) twist drills. Machinability ofAISI 316 austenitic stainless steel was evaluated in terms of thrust force, tool life, surfaceroughness, and hole quality of the drilled holes. Experimental results showed from 14%to 218% improvements for treated tool lives. Thrust force, surface roughness, and holequality are better with treated drills when compared with untreated drills. Theseimprovements were mainly attributed to formation of fine and homogeneous carbide par-ticles and transformation of retained austenite to martensite. Microhardness and micro-structure observations verified these formations. [DOI: 10.1115/1.4007620]Keywords: microstructure, hardness, stainless steel, cryogenic treatment, machinability

INCONEL 718’İN DELİNMESİNDE KESME PARAMETRELERİNİN YÜZEY PÜRÜZLÜLÜĞÜ VE TALAŞ OLUŞUMU ÜZERİNDEKİ ETKİSİNİN ARAŞTIRILMASI

Bu calismada, Inconel 718 super alasiminin kaplamali ve kaplamasiz karbur matkaplarla delinmesi esnasindakesme parametrelerinin, yuzey puruzlulugu ve talas olusumu uzerindeki etkisi analiz edilmistir. Delme deneylerikaplamasiz, TiN ve TiAlN kapli karbur matkaplar kullanilarak, kuru kesme sartlarinda CNC dik islememerkezinde, dort farkli kesme hizi (10, 12,5, 15, 17,5 m/dak) ve uc farkli ilerleme hizi (0,05, 0,075, 0,1 mm/dev)kullanilarak yapilmistir. 5 mm capinda matkaplarla 8 mm derinliginde kor delikler delinmistir. Yuzeypuruzlulugu olcumleri isiginda kesici takimlar arasinda karsilastirma yapilmistir. Genel olarak, yuzeypuruzlulugu acisindan en iyi sonuclar kaplamasiz takimla delinen deliklerden alinmistir. Talas olusumuincelendiginde yapilan butun deneylerde, ilk delikte meydana gelen talas seklinin kopuk talas ya da kucuk adimlihelisel talas seklinde oldugu gorulmustur.