Shock-resisting tool steels

Shock-resisting tool steels S Shock-resistant tool steels, with Cr-W, Sl-Mo, and Sl-Mn as major alloys, are strong and tough, but they are not as wear resistant as many other tool steels. These steels resist sudden and repeated loadings. Apphcatlons include pneumatic tooling parts, chisels, punches, shear blades, bolts, and springs... 

Straight WC—Co tools are not suitable for machining steels that produce long chips because straight grades undergo crater wear from diffusion of WC into the steel chip surface. However, soHd solutions of WC—TiC, WC—TiC—TaC, etc, resist this type of chemical attack. In addition, tantalum carbide can improve thermal-shock resistance. Steel cutting compositions thus typically contain WC—TiC—(Ta,Nb)C—Co. Tantalum carbide is often added as (Ta,Nb)C because the chemical similarity between TaC and NbC makes their separation expensive. 

Special alloy tool steel forgings with the necessary properties of red hardness, shock resistance, and abrasion resistance are used in the manufacture of shear knives for hot work. The knives are frequently used in shears where water is employed as a coolant. Applications include hot strip mill crop shears, flying shears in strip, billet, and bar mills, as well as cobble and dividing shears. 

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