Machinability by Milling of Gray Cast Iron

2014 ◽  
Vol 657 ◽  
pp. 88-92
Author(s):  
Traian Grămescu ◽  
Constantin Cărăușu

In the laboratory of cutting machining technologies from the “Gheorghe Asachi” Technical University of Iaşi, a series of investigations on the machinability of cast iron samples having various structures were designed and developed. The aim of the research was to know and to explain the way in which various constituents of some iron castings exert influence on the degree of wear of a milling tool made of high speed steel. Within this research, mathematical empirical models were determined, in order to calculate the cutting speed v60, considered as an indicator for the evaluation of machinability. The research allowed establishing the factors able to have a major influence on tool wear phenomenon and obtaining thus a more complete image concerning the machinability of grey iron used for castings.

2009 ◽  
Vol 407-408 ◽  
pp. 500-503 ◽  
Author(s):  
Satoshi Furuya ◽  
Nobuaki Ozoe ◽  
Yasuo Yamane

This paper focuses on the influence of difference of tool materials on generation of wear protective layer when turning gray cast iron containing Al and Mg. In this experiment, the gray cast iron to which small quantities of Al and Mg was added were cut with cermet, P grade carbide (P10), silicon nitride ceramics (Si3N4), titanium nitride (TiN) coated carbide and K grade carbide (K10) at high speed. In turning gray cast iron containing Al and Mg with cermet, the tool wear was significantly reduced compared to that resulting from the cutting of conventional gray cast iron. Further, the protective layer consisting of nonmetallic inclusions in the work material was formed on the tool surface. In addition to cermet, this layer was formed on tool surface of Si3N4 and TiN coated carbide. The elements of Al and Mg added to the work materials were detected in the layers formed on these tool surfaces as well as cermet. The inhibiting effect on tool wear was also caused when turning with P10. However, P10 had much greater wear than cermet. On the other hand, in the case of turning with K10, the effect reducing wear with the addition of Al and Mg was not caused. The wear increased as cutting speed increased regardless of work materials.


2010 ◽  
Vol 126-128 ◽  
pp. 755-759 ◽  
Author(s):  
Ming Chen ◽  
Xiao Hui Zhang ◽  
Bing Han ◽  
Bin Rong ◽  
Gang Liu

The engineblock and cylinderhead of automobile are usually made of cast iron, and tapping of blind holes is one of the most demanding operations. As usual, tapping is the final process for an engineblock, and the failure of taps can disable the engineblock possibly. The productivity is restricted because of the low cutting speed and poor wear resistance of high speed steel (HSS) taps. Thereby, according to the demand on high speed cutting and low tact time of modern engine production lines, several new typical special tungsten carbide taps are developed and their cutting performance are evaluated in comparison with the commercial taps. In the process of tapping blind holes in gray cast iron and ductile cast iron, several aspects are studied comparatively such as wear mechanism of the first complete and the last incomplete tooth, tap structure, wear of TiCN coating and effects of coolant on cutting performance of taps. This study indicates that straight coated taps with fewer flutes are suitable for high speed tapping of cast iron.


Alloy Digest ◽  
1980 ◽  
Vol 29 (8) ◽  

Abstract RED CUT COBALT steel is made by adding 5% cobalt to the conventional 18% tungsten -4% chromium-1% vanadium high-speed steel. Cobalt increases hot or red hardness and thus enables the tool to maintain a higher hardness at elevated temperatures. This steel is best adapted for hogging cuts or where the temperature of the cutting point of the tool in increased greatly. It is well adapted for tools to be used for reaming cast-iron engine cylinders, turning alloy steel or cast iron and cutting nonferrous alloys at high speeds. This datasheet provides information on composition, physical properties, and hardness as well as fracture toughness. It also includes information on forming, heat treating, and machining. Filing Code: TS-367. Producer or source: Teledyne Vasco.


2013 ◽  
Vol 465-466 ◽  
pp. 642-646 ◽  
Author(s):  
Abu Bakar Mohd Hadzley ◽  
Mohamad Raffi Nurul Fatin ◽  
Raja Abdullah Raja Izamshah ◽  
Nur Izan Syahriah Hussein ◽  
Ahmad Siti Sarah ◽  
...  

The high speed machining (HSM) of gray cast iron for manufacture mold and dies involve many different cutting tool from deep hole drills to smallest ball nose end mills [. Due to the demand of fast and high productivity, high speed machining (HSM) has been increasingly used to produce mold and dies that are mostly used in automotive industry especially for stamping dies components. The process of HSM sometimes combined together with manual polishing to enhance the die surface into fine mirror finish. Although the manual polishing strongly depends by experience and skill of workers, this technique is the preferable option for polishing of moulds and dies. However, such extensive manual polishing will provide some drawback because of many human factors such as pressure and technique of polishing individual person uses. Therefore, the application high speed machining in manufacturing is still demanding as it can improve surface finishing by reducing manual polishing, reportedly account for up to 30% of the total time [2].


Coatings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 464
Author(s):  
Alain Gil Del Val ◽  
Fernando Veiga ◽  
Octavio Pereira ◽  
Luis Norberto Lopez De Lacalle

Threading holes using tapping tools is a widely used machining operation in the industry. This manufacturing process involves a great tool immersion in the part, which involves both friction and cutting. This makes the use of coatings critical to improving tool life. Four coatings are used based on Physical vapor deposition (PVD) technology—TiN, TiCN, TiAlN and TiAlN+WC/C are compared to uncoated tool performance. The effect of various coatings on the life of M12 × 1.5 tapping tools during threading of through holes 20 mm deep, in GG25 casting plates, dry and applying cutting speed of 50 m/min. The end-of-life criterion has been established based on a cutting torque of 16 N-m. Taking the uncoated tap as a basis for comparison, it is observed that coatings based on PVD technologies increase tool life doubling in the most advantageous case with the TiAlN coating. PVD type coatings provide better protection to wear at cylindrical area of the tool, where the thread profile is finished, than uncoated taps. The teeth located in the cone-cylinder transition zone of the taps suffer the most wear regardless of the coating. However, taps coated with TiAlN+WC/C wear level values is lowest of all the coatings tested, which indicates a strong reinforcement in these teeth.


Author(s):  
Justin L. Milner ◽  
Jeffrey A. Beers ◽  
John T. Roth

Machining is a popular and versatile manufacturing process that is widely used in today’s industry when producing metallic parts; however, limited tool life can make this an expensive and time consuming fabrication technique. Consequently, methods that decrease the rate of tool wear and, thus, increase tool longevity are a vital component when improving the efficiency of machining processes. To this end, cryogenically treating cutting tools (especially high-speed steel tooling) is becoming more commonplace since research has shown that the treated tooling exhibits significantly higher wear resistance. At this point, however, the effect of cryogenic treatments on ceramic tooling has not been established. Considering this, the research herein presents a feasibility study on the effectiveness of using cryogenic treatments to enhance the wear resistance of WG-300 whisker-reinforced ceramic cutting inserts. To begin, the effect of the cryogenic treatment on the insert’s hardness is examined. Subsequently, tool wear tests are conducted at various cutting speeds. Through this study, it is shown that cryogenically treating the ceramic inserts decreases the rate of tool wear at each of the cutting speeds that were tested. However, the degree of wear resistance introduced by cryogenically treating the inserts proved to be highly dependent on the cutting speed, with slower speeds exhibiting greater improvements. Thus, based on this initial study, the cryogenic treatment of ceramic tooling appears to produce beneficial results, potentially increasing the overall efficiency of machining processes.


2002 ◽  
Vol 124 (4) ◽  
pp. 820-832 ◽  
Author(s):  
Jiancheng Liu ◽  
Kazuo Yamazaki ◽  
Hiroyuki Ueda ◽  
Norihiko Narutaki ◽  
Yasuo Yamane

In order to increase the accurate finishing productivity of pearlitic cast iron, face milling by CBN (Cubic Boron Nitride) cutting tools was studied. The main focus of the study is the machinability investigation of pearlitic cast iron with CBN cutting tools by studying the relationships among machining conditions such as feed rate, cutting speed as well as CBN cutting tool type, tool wear, workpiece surface quality, cutting forces, and cutting temperature. In addition, an emphasis is put on the effect of Al additive in pearlitic cast iron on its machinability and tool wear characteristics. High-speed milling experiments with CBN cutting tools were conducted on a vertical machining center under different machining conditions. The results obtained provide a useful understanding of milling performance by CBN cutting tools.


2013 ◽  
Vol 712-715 ◽  
pp. 611-614 ◽  
Author(s):  
Ni Jun Xu ◽  
Jian Bin Lv ◽  
Ting Sun ◽  
Chang Sheng Liu

As withstanding very high loads, thermal cycling leading to thermal fatigue, and severe environmental in the steel industry, rolls with long service life are specially required. High speed steel with high vanadium content is a newly-developed wear-resistance material that has been studied and used in some countries for making steel rolls. As a surface treatment technology, laser cladding can fabricate coating to improve the wear resistance of substrate. In this paper, the substrates for laser cladding were nodular cast iron rolls, Nd: YAG solid pulsed laser was used to explore the feasibility of preparation high vanadium high speed steel (HVHSS) coatings. The Nd: YAG laser cladding results that the coated layers combined metallurgically with the substrate with a lot of microcracks. The average microhardness up to 650 HV is more than 2 times as high as that of the substrate. After laser remelting, a fully dense and crack free HVHHS coating with an excellent metallurgical bonding was deposited. The presence of VC in the coating mainly improves the microhardness of coating up to about 650 HV.


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