Cutting Data for Turning of Steel
Thoroughly describing workpiece materials and cutting tool materials, this book provides machining recommendations for turning, which is one of the major metalcutting processes.
TABLE OF CONTENTS Cutting Data for Turning of Steel
Chapter 2: Cutting Tool Materials
The cutting tool materials for machining of steels are high-speed steels, cemented carbides, cermets, ceramics, and polycrystalline cubic boron nitride.
2.1. High-Speed Steels
According to Metals Handbook, High-speed steels are so named primarily because of their ability to machine materials at high cutting speeds. They are complex iron-base alloys of carbon, chromium, vanadium, molybdenum, or tungsten, or combinations thereof, and in some cases substantial amounts of cobalt. The carbon and alloy contents are balanced at levels to give high attainable hardening response, high wear resistance, high resistance to the softening effect of heat, and good toughness for effective use industrial cutting operations (Ref 3, p.51).
High-speed steels are able to maintain high hardness (often referred to as hot or red hardness) at elevated temperatures: 52 HRC at 1000 F (540 C) and 48 HRC at 1100 F (590 C).
2.1.1. Brief history of high-speed steels development
The earliest cutting tool materials used for chip removal operations were high-carbon steels. Among these was a special grade developed by Robert Mushet, who in 1868 added tungsten to this type of steel. The composition of this unique grade, marketed as R. Mushet s Special Tool Steel, consisted of 2% carbon, 2.5% manganese, 7% tungsten, 0.5% chromium, and 1.1% silicon. This steel had a remarkable capacity to harden during air-cooling after forging or heating and is regarded as the first high-speed steel (Ref 14, p.4).
In the period from 1894 to 1898, Fred Taylor and Maunsel White at the Bethlehem Steel Corporation discovered...
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