Tham khảo tài liệu 'mcgraw-hill machining and metalworking handbook 3rd ed - r. walsh_ d. cormier (mcgraw-hill 2006) ww part 3', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Downloaded from Digital Engineering Library @ McGraw-Hill Copyright 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Hot-work tool steels Chromium base types H11 Chromium-molybdenum-V Good Good Deep Good Good Fair Fair H12 Chromium-molybdenum-tungsten Good Good Deep Good Good Fair Fair H13 Chromium- molybdenum-w Tungsten base types Good Good Deep Good Good Fair Fair H21 Tungsten High-speed tool steels Tungsten base types Good Good Deep Good Good Fair Fair Tl Tungsten 18-4-1 Good Good Deep Poor Good Good Fair T2 Tungsten 18-4-2 Good Good Deep Poor Good Good Fair T4 Cobalt-tungsten 18-4-1-5 Good Fair Deep Poor Best Good Fair T5 Cobalt-tungsten 18-4-2-8 Good Fair Deep Poor Best Good Fair T8 Cobalt-tungsten 14-4-2-5 Molybdenum base types Good Fair Deep Poor Best Good Fair Ml Molybdenum 8-2-1 Good Fair Deep Poor Good Good Fair M2 Molybdenum-tungsten 6-6-2 Good Fair Deep Poor Good Good Fair M3 Molybdenum-tungsten 6-6-3 Good Fair Deep Poor Good Best Fair M4 Molybdenum-tungsten 6-6-4 Special-purpose tool steels Low-alloy types Good Fair Deep Poor Good Best Fair L6 Nickel-chromium Fair Good Medium Fair Poor Fair Fair L7 Chromium Fair Good Medium Fair Poor Good Fair These are intended to emphasize major differences between the groups of steels and do not account for the minor differences in depths of hardening that exist between steels of the same group. This is particularly true of the water-hardening w steels which are frequently furnished with varying degrees of hardenability as listed in Table . Toughness decreases somewhat with increasing depth of hardening. w as shown here indicates water quench o as shown here indicates oil quench. SOURCE Reprinted with permission copyright 1992 Society of Automotive Engineers. Materials Physical Properties Characteristics and Uses Downloaded from Digital Engineering Library @ McGraw-Hill .
