Free Machining Steel: I—Tool-Life Characteristics of Resulfurized Steel

1961 ◽  
Vol 83 (2) ◽  
pp. 163-172 ◽  
Author(s):  
M. C. Shaw ◽  
N. H. Cook ◽  
P. A. Smith

Tool-wear and tool-life characteristics of a series of five steels of different sulfur content are presented for different values of cutting speed, feed, cutting fluid, and cold work. While the presence of manganese sulfide in steel is generally found to extend tool life, certain combinations of speed and feed yield result that indicate the reverse effect. For the group of hot-rolled steels studied, sulfur was found to shorten tool life at certain cutting speeds when the feed was in the vicinity of 0.005 ipr. The hot-rolled steels of low sulfur content exhibit better tool life with high-speed steel tools than with carbide tools when the cutting speed is such as to give a tool life in the vicinity of 4 hr. A tracer device is described that is useful in exploring the nature and extent of the crater and built-up areas on the tool face.

1961 ◽  
Vol 83 (2) ◽  
pp. 175-180 ◽  
Author(s):  
M. C. Shaw ◽  
P. A. Smith ◽  
N. H. Cook

High-speed steel tool life results are presented and discussed for a leaded and nonleaded steel from the same heat. Variables investigated include cutting speed, feed, cutting fluid, and cold work.


1962 ◽  
Vol 84 (1) ◽  
pp. 89-98 ◽  
Author(s):  
E. Usui ◽  
M. C. Shaw

Tools which provide controlled contact on the tool face are used to study the action of free machining steels. The mean normal stress on the tool face σc is found to increase with increased undeformed chip thickness (t = feed) or with a reduction in the controlled length of tool face contact. An increase in σc in turn is found to promote the stability of the built-up edge to higher speeds. The high-speed finish produced with a cut-away tool is thus found to be inferior to that produced with a conventional tool. Manganese sulfide is found to have a similar effect on surface finish, but lead tends to improve the finish obtained at a high cutting speed. The cut-away tool provides improved low-speed finish in all cases as does the addition of either manganese sulfide or lead to the steel. Manganese sulfide is found to become more effective with increased undeformed chip thickness t, while lead behaves in the opposite manner. This observation along with several others is in agreement with the idea that manganese sulfide is a poor solid “lubricant,” while lead is an effective solid lubricant. An optimum chip-tool contact length appears to exist at which the tool life will be a maximum at any combination of cutting speed and feed. From this it follows that an optimum combination of sulfur or lead content, degree of cold work, cooling capacity of cutting fluid, or extent of tool-face limitation exists, since all of these quantities influence the resultant length of contact between chip and tool.


Author(s):  
Mitsuru Hasegawa ◽  
Tatsuya Sugihara

Abstract In cutting of Ti-6Al-4V alloy, the cutting speed is limited since a high cutting temperature leads to severe tool wear and short tool life, resulting in poor production efficiency. On the other hand, some recent literature has reported that various beneficial effects can be provided by forming micro-textures on the tool surface in the metal cutting process. In this study, in order to achieve high-performance machining of Ti-6Al-4V, we first investigated the mechanism of the tool failure process for a cemented carbide cutting tool in high-speed turning of Ti-6Al-4V. Based on the results, cutting tools with micro textured surfaces were developed under the consideration of a cutting fluid action. A series of experiments showed that the textured rake face successfully decreases the cutting temperature, resulting in a significant suppression of both crater wear and flank wear. In addition, the temperature zone where the texture tool is effective in terms of the tool life in the Ti-6Al-4V cutting was discussed.


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.


2012 ◽  
Vol 566 ◽  
pp. 217-221 ◽  
Author(s):  
Ali Davoudinejad ◽  
Sina Alizadeh Ashrafi ◽  
Raja Ishak Raja Hamzah ◽  
Abdolkarim Niazi

Aluminum alloy is widely used in industry and various researches has been done on machiability of this material mainly due to its low weight and other superior properties. Dry machining is still interesting topic to reduce the cost of manufacturing and environmental contaminations. In present study dry machining of Al 2024 investigated on tool life, tool wear mechanisms, hole quality, thrust force and torque. Different types of high speed steel (HSS) tools utilized at constant feed rate of 0.04 mm/rev and cutting speeds within the range of 28 and 94 m/min. Experimental results revealed that HSCo drills, performed better than HSS drills in terms of tool life and hole quality. The main wear mechanisms which analyzed by scanning electron microscope found abrasive and adhesion wear on flank face, besides, BUE observed at chisel and cutting edges. However tool wear and BUE formation found more significant at high cutting speed. In terms of thrust force, two facet HSCo tools, recorded higher thrust force than four facet HSS drills.


1969 ◽  
Vol 91 (3) ◽  
pp. 585-596 ◽  
Author(s):  
M. Field ◽  
N. Zlatin ◽  
R. Williams ◽  
M. Kronenberg

In Part 1 of this two-part paper, generalized equations for cost and production were presented for five major types of machining operations: turning, milling, drilling, reaming, and tapping. In addition, detailed cost equations were presented for the turning operation for three types of lathe tools: brazed carbide tools, throwaway tools, and solid high-speed steel tools. The present paper, Part 2, presents the detailed cost and production analysis for the remaining machining operations: milling, drilling, reaming, and tapping. Individual equations are developed within each machining category for the major types of cutters and tools involved in the operation. Examples are presented illustrating the use of these equations on specific problems. In addition, equations are developed for calculating the optimum cutting speeds and tool life corresponding to minimum costs and maximum production rates assuming that the tool life-cutting speed follows the simplified Taylor equation. The optimized equations enable one to interpolate and extrapolate the cost and production determinations. Care must be exercised to check experimentally the interpolated or extrapolated values to verify the results from the calculations.


2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Fritz Klocke ◽  
Kristian Arntz ◽  
Gustavo Francisco Cabral ◽  
Martin Stolorz ◽  
Marc Busch

In this experimental study, the cutting performance of ball-end mills in high-speed dry-hard milling of powder metallurgical steels was investigated. The cutting performance of the milling tools was mainly evaluated in terms of cutting length, tool wear, and cutting forces. Two different types of hardened steels were machined, the cold working steel HS 4-2-4 PM (K490 Microclean/66 HRC) and the high speed steel HS 6-5-3 PM (S790 Microclean/64 HRC). The milling tests were performed at effective cutting speeds of 225, 300, and 400 m/min with a four fluted solid carbide ball-end mill ( = 6, TiAlN coating). It was observed that by means of analytically optimised chipping parameters and increased cutting speed, the tool life can be drastically enhanced. Further, in machining the harder material HS 4-2-4 PM, the tool life is up to three times in regard to the less harder material HS 6-5-3 PM. Thus, it can be assumed that not only the hardness of the material to be machined plays a vital role for the high-speed dry-hard cutting performance, but also the microstructure and thermal characteristics of the investigated powder metallurgical steels in their hardened state.


2014 ◽  
Vol 783-786 ◽  
pp. 1142-1146
Author(s):  
Takaomi Itoi ◽  
Tomoaki Sudo ◽  
Kyosuke Yoshimi

Recycle-type Fe3Al (hereinafter designated as Re-Fe3Al) based alloys reinforced by the carbides of TiC or ZrC were processed by the high frequency induction melting method using a high-carbon Cr steel sludge, Al can scraps and the transition metals of Ti or Zr. The carbides were synthesized by in-situ reaction between the transition metal and carbon in the molten iron aluminum alloy. Vickers hardness values are 309HV0.5 for Re-Fe3Al/TiC alloy, and 473HV0.5 for Re-Fe3Al/ZrC alloy, which are higher than that of P-Fe3Al (preprared from pure-Fe and-Al). The cutting performance of the Re-Fe3Al baed alloys was compared with a High-Speed-Steel (HSS) by cutting tests for pure-Cu extruded bar (C1020) using a lathe under a dry condition. Tool life limit was estimated from frank wear length after the cutting tests of C1020 by finish-machining. Tool life limit of Re-Fe3Al/TiC alloy is more than16 min; P-Fe3Al was 12 min; HSS was 8 min, Re-Fe3Al/ZrC alloy was 7 min at the cutting speed of 100m/min. Also, tool life limit of the Re-Fe3Al/TiC alloy was more than twice times as long as that of the HSS at the cutting speed of 300/min. The relationship between cutting speed and tool life limit clearly indicated that the Re-Fe3Al/TiC alloy was better than the HSS at a higher cutting speed. Therefore, it was concluded that Re-Fe3Al/TiC alloy has excellent cutting tool performance.


2016 ◽  
Vol 686 ◽  
pp. 240-245
Author(s):  
Tomáš Vopát ◽  
Jozef Peterka ◽  
Vladimír Šimna ◽  
Ivan Buranský

The article deals with the tool life of ball nose end mills and surface roughness of steel C45 depending on up-copying and down-copying. The cemented carbide and high speed steel was used as tool material. Furthermore, the new and sharpened cutting tools were also compared. In the experiment, the cutting speed, feed rate, axial and radial depth of cut were not changed. The results show different achieved surface roughness of machined material C45 and tool life of ball nose end mills depending on the copy milling strategy for various tool materials.


Alloy Digest ◽  
1957 ◽  
Vol 6 (8) ◽  

Abstract MOTUNG 652 is an intermediate molybdenum-tungsten type of high-speed steel conforming to the M-2 analysis. It is available with normal sulfur content or with high sulfur for free machining properties. This datasheet provides information on composition, physical properties, hardness, tensile properties, and compressive and bend strength as well as fracture toughness. It also includes information on forming, heat treating, and machining. Filing Code: TS-61. Producer or source: Cyclops Corporation.


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