Steel R18 Research Articles

Structure and cutting properties of small drills made of R18 steel

1. Small drills made of R18 steel supplied to tool producing plants have inconsistent geometric parameters, hardness, microstructures, and cutting properties. 2. A thorough adherence to geometric parameters and the heat treatment technique does not guarantee consistent cutting properties because the quality of the drills depends on the structure of the steel as delivered. 3. To increase the quality of drills, it is necessary that the metallurgical plants supply material with a guaranteed structure in terms of pearlite grade.

Effect of thermovibromechanical treatment upon the wear resistance and strength of grade R18 steel drills

Effect of thermovibromechanical treatment upon the wear resistance and strength of grade R18 steel drills

Effect of the size of secondary and eutectoid carbides on the properties of R18 steel

The quality of high speed cutting steel as delivered must be checked not only for its carbide grade but also for the pearlite grade.

Investigation of R12 steel

1. The cutting qualities of tools made of R12 steel are as good as those of cutters made of the more expensive R18 steel. 2. Extensive industrial tests of R12 steel are needed in view of its utilization in industry.

Effect of diamond polishing on surface layers of quenched steel R18

Effect of diamond polishing on surface layers of quenched steel R18

Low-temperature gas cementation of cutting tools made of R9 and R18 steels

Low-temperature gas cementation of cutting tools made of R9 and R18 steels

Effect of ultrasonic vibration on the mechanical properties of R18 steel

Effect of ultrasonic vibration on the mechanical properties of R18 steel

Increase of the strength of R18 steel by compression

Compression under a pressure of 7000 kg/cm2 increases the strength of cutting tools made of R18 steel 40–50%. The growth of the grains does not decrease this effect. Simultaneous compression and heat treatment considerably simplifies the technology of manufacturing cutting tools, which is of great practical importance in the mass production of cutting tools with complex shapes (milling cutters, drills, chisels, etc.).

Carbide phase in R18 steel

1. R18 steel contains mainly the Fe3W3C carbide. Small amounts of (Cr3Fe)23C6 and WC may also be present. 2. The carbides are irregularly distributed through the section of the ingots (or rods) and different carbides and in different amounts are present in the central and peripheral parts of the ingots. 3. There is no great difference in the distribution or shape of the carbides. 4. The smelting method and subsequent treatment have no significant effects on the qualitative composition of the carbide phase.

Investigation of the heat-treatment process for steel R14F4

1. The hardness of steel R14F4 after threefold tempering depends substantially on the temperature and the duration of the heating to the hardening temperature: a) an increase of the holding time to 12, 15, and 18 sec/mm, at all hardening temperatures, enhances the hardness obtained after triple tempering at 560 and 580°; b) the average hardness value after threefold tempering at 560° is higher than after identical treatment at 580°. 2. The highest red hardness values (Rh 60) are attainable on application of the following heat-treatment conditions: quenching from 1260°, holding for 15 and 18 sec/mm, triple tempering at 560°. 3. The steel R14F4 thread milling cutters heat-treated under optimum conditions display a performance 40% superior to that of cutters made from steel R18.

A new technique for preparing bright bar from high speed steel R18

A new technique for preparing bright bar from high speed steel R18

Medium-tungsten high-speed steel alloyed with cobalt and vanadium

1. A medium-tungsten, Co-V high-speed steel R9F4K8M shows about twice the tool life of standard steel R18 in both continuous and intermittent machining of austenitic heatresistant steels. 2. Sub-zero treatment does not affect its cutting properties. A slight increase of tool life was found after a double tempering at 520°C. 3. A co-V steel with 9% W was inferior to a similar steel with 18% W. However, the advantages of the hightungsten steel were clearly displayed only on hard-tomachine materials under conditions of impact (interrupted) tool operation.

Effect of heating time during hardening on the structure and properties of high-speed steel

1. When heating high-speed steel blanks for hardening, the process of saturating the solid solution with carbon and alloying elements does not end at the moment through-heating is completed. The saturation of austenite continues over a certain period of time which depends on the initial miscrostructure, the steel composition and the selected hardening temperature. It gradually vanishes later on. 2. Soaking after through-heating which is required to complete the basic stage of the passage of carbides into solid solution, is 1.16 min. for steel R18 quenched from 1275°C, and 0.6 min. for steel R9 quenched from 1230°C. 3. An additional increase in soaking time serves no useful purpose because it results in grain growth and a dis-advantageous change of the shape, size and distribution of the carbides this leading to a deterioration of mechanical properties.