Friction, Lubrication, and Wear Technology (1997) Part 12 ppt

Mn-Cr- Ni-Mo 0.24 1.22 0.20 1.43 3.15 0.25 0.022 0.019 . . . . . . Mn-Cr- Ni-Mo 0.25 1.17 0.30 1.39 0.87 0.76 0.022 0.019 . . . . . . Mn-Cr- Ni-Mo 0.25 1.22 0.28 1.40 1.58 0.47 0.022 0.019 . . . . . . Mn-Ni- Mo-Cu-B 0.27 1.90 0.23 . . . 0.74 0.17 . . . . . . 0.29Cu, 0.014Al, 0.0016B, 0.04Ti . . . Mn-Ni- Mo-B 0.27 2.10 0.30 . . . 0.82 0.17 . . . . . . 0.16Cu, 0.06Al, 0.0017B, 0.04Ti . . . Mn-Mo- Cu-B 0.28 1.60 0.25 0.05 0.06 0.16 0.011 0.025 0.28Cu, 0.023Ti, 0.049Al, 0.002B, 0.004N . . . Mn-Ni- Mo-B 0.29 2.36 0.24 . . . 0.86 0.15 . . . . . . 0.08Cu, 0.015Al, 0.0017B, 0.04Ti . . . Cr-Mo-B 0.30 0.82 0.22 0.35 0.04 0.27 0.010 0.017 0.03Cu, 0.026Ti, 0.039Al, 0.001B, 0.006N . . . Cast lean manganese-austenitic steels 6Mn-5Cr- 1Mo 0.7 6.02 0.53 5.07 . . . 1.01 0.019 0.015 . . . . . . 6Mn-5Cr- 1Mo 1.05 6.12 0.54 5.04 . . . 1.00 0.021 0.019 . . . . . . 6Mn-5Cr- 1Mo 1.22 6.02 0.55 4.96 . . . 0.95 0.020 0.019 . . . . . . 9Mn- 1Mo-Ti 1.10 9.52 0.59 . . . . . . 1.07 . . . . . . 0.36Ti . . . 9Mn- 1Mo-Ti 1.21 9.13 0.82 . . . . . . 0.99 . . . . . . 0.134Ti . . . 9Mn- 1Mo-Ti 1.27 9.49 0.56 . . . . . . 1.08 . . . . . . 0.32Ti . . . 9Mn- 1Mo-Ti 1.30 8.61 0.50 . . . . . . 0.93 . . . . . . 0.27Ti . . . 9Mn- 1Mo-Ti 1.36 8.47 0.49 . . . . . . 1.00 . . . . . . 0.064Ti . . . Cast austenitic-manganese steels 12Mn- 1Mo 0.65 12.74 0.51 . . . . . . 0.96 . . . . . . . . . . . . 12Mn 0.93 12.97 0.50 . . . . . . . . . . . . . . . . . . . . . 12Mn- 1Mo 0.93 12.0 0.5 . . . . . . 1.0 . . . . . . . . . . . . 12Mn- 1Mo 0.97 12.5 0.5 . . . . . . 0.94 . . . . . . . . . . . . 12Mn 1.1 12.5 0.5 . . . . . . . . . . . . . . . . . . . . . 12Mn 1.24 12.5 0.5 . . . . . . 0.05 . . . . . . . . . . . . 12Mn- 1Mo-Ti 1.26 12.5 0.5 . . . . . . 0.96 . . . . . . 0.25Ti . . . 12Mn- 1Mo-Ti 1.29 12.5 0.5 . . . . . . 0.94 . . . . . . 0.018Ti . . . 12Mn- 1Mo-Ti 1.29 12.5 0.5 . . . . . . 1.02 . . . . . . 0.13Ti . . . 12Mn- 1Mo-Ti 1.31 12.5 0.5 . . . . . . 0.92 . . . . . . . . . . . . Cr-Ni-Mo 0.27 . . . . . . 1.0 3.0 2.0 . . . . . . . . . . . . AISI 4340 0.4 0.7 0.3 0.8 1.8 0.25 . . . . . . . . . . . . Mn-Cr- 0.65 1.75 0.13 0.75 . . . 0.13 . . . . . . . . . . . . Mo C-Mn 0.80 1.00 0.18 . . . . . . . . . . . . . . . . . . . . . Cast steels Si-Cr-Mo 0.34 0.84 1.92 1.92 0.22 0.57 . . . . . . . . . . . . Mn-Si- Cr-Mo 0.43 1.39 1.46 0.83 . . . 0.49 . . . . . . . . . . . . Mn-Si- Cr-Ni-Mo 0.55 1.44 1.32 0.68 0.96 0.63 . . . . . . 0.08Cu . . . Mn-Si- Cr-Mo 0.63 1.44 1.48 0.83 . . . 0.49 . . . . . . . . . . . . Cr-Mo 0.63 0.71 0.58 2.30 . . . 0.34 0.028 . . . . . . . . . Cr-Mo 0.88 0.95 0.72 2.44 . . . 0.35 0.027 . . . . . . . . . Carburizing steels 1015 0.13- 0.18 0.30- 0.60 . . . . . . . . . . . . . . . . . . . . . Little used; mainly for small thin parts such as needle rollers 1019 0.15- 0.20 0.70- 1.00 . . . . . . . . . . . . . . . . . . . . . . . . 1020 0.18- 0.23 0.30- 0.60 . . . . . . . . . . . . . . . . . . . . . . . . 1118 0.14- 0.20 1.30- 1.60 . . . . . . . . . . . . . . . . . . . . . Free-machining carburizing grade resulfurized 4023 0.20- 0.25 0.70- 0.90 0.15- 0.30 . . . . . . 0.20- 0.30 . . . . . . . . . . . . 4027 0.25- 0.30 0.70- 0.90 0.20- 0.35 . . . . . . 0.20- 0.30 . . . . . . . . . Moderate strength and toughness 4022 0.20- 0.25 0.70- 0.90 0.20- 0.35 . . . . . . 0.35- 0.45 . . . . . . . . . . . . 5120 0.17- 0.22 0.70- 0.90 0.15- 0.30 0.70- 0.90 . . . . . . . . . . . . . . . . . . 4118 0.18- 0.23 0.70- 0.90 0.15- 0.30 0.40- 0.60 . . . 0.08- 0.15 . . . . . . . . . . . . 4720 0.17- 0.22 0.50- 0.70 0.35- 0.55 0.35- 0.55 0.90- 1.20 0.15- 0.25 . . . . . . . . . Cr and Ni produce increased hardenability for heavy sections (large roller bearings) 4820 0.18- 0.23 0.50- 0.70 0.15- 0.30 . . . 3.25- 3.75 0.20- 0.30 . . . . . . . . . . . . 4320 0.17- 0.22 0.45- 0.65 0.15- 0.30 0.40- 0.60 1.65- 2.00 0.20- 0.30 . . . . . . . . . . . . 8620 0.18- 0.23 0.70- 0.90 0.15- 0.30 0.40- 0.60 0.40- 0.70 0.15- 0.25 . . . . . . . . . . . . 9310 0.08- 0.13 0.45- 0.65 0.15- 0.30 1.00- 1.40 3.00- 3.50 0.08- 0.15 . . . . . . . . . For very high shock resistance; high fatigue resistance; surface carbon content must not exceed 0.9% to avoid retained austenite 3310 0.08- 0.13 0.45- 0.60 . . . 1.40- 1.75 3.25- 3.75 . . . . . . . . . . . . . . . Table 2 Abrasive wear data for selected steels Type Heat treatment Hardness, HB Gouging wear ratio Rubber wheel weight loss, g AISI 4140 (0.40 C) 845 °C (1550 °F), oil quenched 582 . . . 0.219 AISI 4140 (0.40 C) 845 °C (1550 °F), oil quenched, 540 °C (1000 °F) 550 . . . 0.235 AISI 4140 (0.40 C) 845 °C (1550 °F), oil quenched, 540 °C (1000 °F) 499 . . . 0.410 AISI 4140 (0.40 C) 845 °C (1550 °F), oil quenched, 540 °C (1000 °F) 363 . . . 0.531 AISI 4340 (0.40 C) Normalized 320 0.674 . . . AISI 4340 (0.40 C) Quenched 650 °C (1200 °F) 340 0.716 . . . AISI 4340 (0.40 C) Quenched 205 °C (400 °F) 520 0.232 . . . AISI 1085 (0.82 C) Hardened and tempered 456 . . . 0.281 AISI 1090 (0.95 C) Hardened and tempered 450 . . . 0.278 AISI 1090 (0.98 C) Hardened and tempered 455 . . . 0.220 6Cr-1Mo (0.88 C) 1065 °C (1950 °F), air cooled, 230 °C (450 °F) 601 0.112 . . . 6Cr-1Mo (0.88 C) 1065 °C (1950 °F), air cooled, 540 °C (1000 °F) 601 0.148 . . . 5Mn-1Mo-2Cr (1.0 C) 1040 °C (1900 °F), furnace cooled 288 0.245 . . . 6Mn-1Mo (1.27 C) 1040 °C (1900 °F), water quenched, 60 °C (140 °F) 200 0.192 . . . 6Mn-1Mo, Ti (1.23 C) 1040 °C (1900 °F), water quenched, 60 °C (140 °F) 200 0.170 . . . 6.5Mn-1Mo (1.01 C) 1040 °C (1900 °F), furnace cooled 240 0.292 . . . 6.5Mn-1Mo-2Cr (0.99 C) 1040 °C (1900 °F), furnace cooled 241 0.316 . . . 6.5Mn-1Mo-5Cr (1.0 C) 1040 °C (1900 °F), furnace cooled 246 0.324 . . . 6.5Mn-3Mo-2Cr (1.02 C) 1040 °C (1900 °F), furnace cooled 241 0.294 . . . 6.5Mn-2Cr (1.00 C) 1040 °C (1900 °F), furnace cooled 474 0.329 . . . 8Mn-1Mo-1Cr (1.00 C) 1040 °C (1900 °F), furnace cooled 229 0.337 . . . 9Mn-1Mo (1.27 C) 1065 °C (1950 °F), water quenched, 60 °C (140 °F) 206 0.219 . . . 9Mn-1Mo, Ti (1.24 C) 1065 °C (1950 °F), water quenched, 60 °C (140 °F) 199 0.213 . . . 12Mn (0.93 C) 1040 °C (1900 °F), water quenched 185 0.328 . . . 12Mn (1.00 C) 1040 °C (1900 °F), water quenched 199 0.279 . . . 12Mn (1.24 C) 1040 °C (1900 °F), water quenched 198 0.212 . . . 12Mn (1.27 C) 1065 °C (1950 °F), water quenched, 60 °C (140 °F) 211 0.207 . . . Not only is there a large variety of steels from which to choose, but within those grades of steels, various heat treatments are possible, resulting in a greater variety of microstructures. The microstructure of steel can have a significant effect on wear resistance (Table 3). Microstructure can also influence corrosion resistance, toughness, dimensional stability, residual stresses, and fatigue resistance. Table 3 Hardness, toughness, and abrasive wear data for abrasion-resistant steel alloys Charpy V-notch impact energy Weight loss, g Material Hardness, HB J ft · lbf Gouging wear ratio (a) Pin Rubber wheel Microstructure (b) Wrought steels Mn-Mo-Nb (0.06C) 212 146 108 1.26 0.1429 . . . F Mn-Mo-Nb (0.06C) 228 146 108 1.12 0.1397 . . . F Mn-Mo-Nb (0.08C) 187 106 78 1.51 0.1560 . . . F Mn-Cr-Ni-Mo-Cu-V (0.11C) 290 23 17 0.88 0.1240 . . . B,M Mn-Cr-Ni-Mo-Cu-V (0.11C) 290 . . . . . . 0.80 0.1248 . . . B,M Mn-V (0.15C) 225 85 63 (c) 1.20 . . . . . . F,p Mn-Cr-Ni-Mo-Cu-V (0.16C) 333 . . . . . . 0.75 0.1179 . . . M,B T-1 type A (0.19C) 260 57 42 1.08 0.1353 0.845 M,B T-1 type A (0.19C) 376 . . . . . . 0.64 0.1240 . . . F,c Mn-Cr-Ni-Mo-Cu-V (0.20C) 380 69 51 0.48 0.1123 . . . B,M Mn-Cr-Ni-Mo-Cu-V (0.20C) 380 . . . . . . 0.50 0.1123 . . . B,M Mn-Ni-Mo (0.21C) 444 . . . . . . 0.39 0.1063 0.496 M,B AISI 1020 (0.22C) 106 163 120 1.87 0.156 . . . F,p Mn-Ni-Mo (0.24C) 251 60 44 0.84 0.1290 . . . F,c Mn-Cr-Ni-Mo (0.24C) 263 47 35 0.79 0.1265 . . . F,c Mn-Cr-Ni-Mo (0.25C) 273 46 34 0.77 0.1257 . . . F,c Mn-Cr-Ni-Mo (0.25C) 294 41 30 0.66 0.1199 . . . F,c Mn-Cr-Ni-Mo (0.25C) 286 47 35 0.71 0.1226 . . . F,c Mn-Ni-Mo-Cu-B (0.27C) 333 . . . . . . 0.69 0.1215 0.713 M,B Mn-Ni-Mo-B (0.27C) 394 . . . . . . 0.67 0.1211 0.662 M,B Mn-Mo-Cu-B (0.28C) 379 . . . . . . 0.72 0.1216 0.630 M,B Mn-Mo-Cu-B (0.28C) 434 . . . . . . 0.52 0.1162 0.550 M,B Mn-Ni-Mo-B (0.29C) 462 . . . . . . 0.47 0.1088 0.512 M,B Cr-Mo-B (0.30C) 395 . . . . . . 0.59 0.1156 0.520 M,B Cr-Mo-B (0.30C) 456 . . . . . . 0.44 0.1108 0.440 M,B Cr-Ni-Mo (0.27C) 510 . . . . . . 0.36 0.0954 0.756 M Cr-Ni-Mo (0.27C) 520 . . . . . . 0.46 0.0964 0.738 M AISI 4340 (0.4C) 320 8.1 6.0 0.67 . . . . . . F,P AISI 4340 (0.4C) 340 29.8 22.0 0.72 . . . . . . F,c AISI 4340 (0.4C) 520 10.6 7.8 0.23 . . . . . . M Mn-Cr-Mo (0.65C) 600 . . . . . . . . . . . . 0.0760 M C-Mn (0.80C) 292 . . . . . . . . . . . . . . . P Cast lean manganese-austenitic steels 6Mn-5Cr-1Mo (0.7C) 339 6.8 5.0 0.30 . . . . . . A,c 6Mn-5Cr-1Mo (0.7C) 243 25 18.3 0.34 . . . . . . A,c 6Mn-5Cr-1Mo (1.0C) 352 5.4 4.0 0.27 . . . . . . A,c 6Mn-5Cr-1Mo (1.0C) 285 12 9.0 0.29 . . . . . . A,c 6Mn-5Cr-1Mo (1.2C) 385 4.7 3.5 0.27 . . . . . . A,c 6Mn-5Cr-1Mo (1.2C) 275 7.9 5.8 0.28 . . . . . . A,c 9Mn-1Mo-Ti (1.1C) 207 41 30 0.34 . . . . . . A 9Mn-1Mo-Ti (1.2C) 224 20 14.7 0.21 . . . . . . A 9Mn-1Mo-Ti (1.25C) 207 65 48 0.27 . . . . . . A 9Mn-1Mo-Ti (1.3C) . . . 24 18 0.25 . . . . . . A 9Mn-1Mo-Ti (1.35C) 208 22 16.3 0.18 . . . . . . A Cast austenitic-manganese steels 12Mn-1Mo (0.65C) 191 119 88 0.42 . . . . . . A 12Mn (0.95C) 185 138 102 0.33 . . . . . . A 12Mn-1Mo (0.95C) 188 72 53 0.32 0.0871 . . . A,p 12Mn-1Mo (1.09C) 192 145 107 0.29 . . . . . . A 12Mn (1.1C) 199 . . . . . . 0.28 0.0821 . . . A 12Mn (1.25C) 198 80 59 0.21 . . . . . . A 12Mn-1Mo-Ti (1.25C) 201 72 53 0.21 . . . . . . A 12Mn-1Mo-Ti (1.3C) 204 87 64 0.22 . . . . . . A 12Mn-1Mo-Ti (1.3C) 201 77 57 0.22 . . . . . . A 12Mn-1Mo-Ti (1.3C) 199 34 25 0.21 . . . . . . A (a) Weight loss of test specimen divided by the weight loss of reference specimen (T- 1 type A steel, 260 HB). (b) A, austenite; M, martensite; F, ferrite; B, bainite; C and c, carbide; P and p, pearlite; lower case letters indicate small amounts. (c) size impact specimen Steel Transformation Diagram When carbon steel is heat treated by quenching from a high temperature, the resulting room-temperature microstructures are not those shown in the equilibrium diagram. Instead, a temperature-time-transformation diagram (TTT) diagram is used to describe these changes. A typical diagram for AISI 1095 steel is shown in Fig. 3. The left side of the diagram shows the temperature in both centigrade and fahrenheit. The right side of the diagram shows the hardness of the steel at room temperature. Note that the maximum hardness attainable for this steel is 66 HRC. The first heavy curved line in the chart represents the time at which transformation begins. In hypoeutectoid steels, this initial transformation consists of the separation of proeutectoid ferrite. This is followed by the separation of ferrite and carbide in the form of pearlite. The beginning of the pearlite formation is represented by the second heavy curved line. Below the knee of the curve ( 540 °C, or 1000 °F), the transformation product is bainite, a phase similar in morphology to martensite but not quite as hard. If the solid curved line is not crossed before the martensite start temperature (M s ) horizontal dashed line, martensite is the product of austenite decomposition. This diagram shows that a very rapid quench is required to produce martensite (that is, one must go from 885 °C, or 1625 °F, past the knee in <1 s a quench rate of approximately 360 °C/s, or 650 °F/s). Bainite can be obtained by rapid quenching to a temperature just below the knee and holding at that temperature until the transformation is complete, followed by a quench to room temperature. Fig. 3 Time-temperature-transformation diagram for SAE 1095 eutectoid carbon steel (0.9C- 0.3 Mn). Austenitized at 885 °C (1625 °F); grain size, 4 to 5. Ae 1 , equilibrium transformation temperature A variety of microstructures can be obtained by controlling the quench processes. Martensite is the hardest phase and provides the highest wear resistance in the absence of any fracture-initiating conditions. If a tougher material is desired, bainite is the best wear-resistant phase. Of course, tempering (that is, heating the martensite to an elevated temperature below the austenitizing temperature and holding to reduce the lattice strain) is a process that can be used to increase the ductility and toughness of martensite. The maximum martensitic hardness attainable in a steel is a function of the carbon content (Fig. 2). Wear Properties of Carbon Steel Hardness as a Function of Carbon Content. Under the abrasive conditions found in mining and construction operations, wear rates of steel can be related to hardness and carbon content. For example, wear tests were conducted on steel rods used on a vibrating screen at an ore crushing plant. These screens were equipped with rods 6.5 mm ( in.) or 4.8 mm ( in.) in diameter, 585 mm (23 in.) long, and equally spaced in several rows across the rod deck of vibrating screens used to size -25 mm (-1 in.) siliceous ore into ±9.5 mm (± in.) sizes. The wear rate of all test rods was compared with that of 1070 high-carbon steel that was oil quenched and tempered to 44 HRC. To ensure that each type of steel would be exposed to the same abrasion, rods were alternated in groups of five across the screen. Wear rates based on the loss of weight for the different steels and hardnesses are shown in Fig. 4. Although the 0.30C-13Cr stainless steel showed the best resistance to wear, 1080 steel austempered to 57 HRC was found to be more cost effective. Fig. 4 Effect of hardness and carbon content on the abrasive wear of selected steel rods used in an ore crusher Improving Wear Properties of Mild Steels. Mild steel demonstrates poor wear resistance and resistance to surface damage during dry sliding. The use of mild steel in sliding surface contact requires surface treatment, such as hardening or coating, and the selection of a "compatible" mating material such as bronze or babbitt. Where hard minerals come in contact with steel, wear is very rapid unless the steel surface is hardened or coated with a very hard material. Corrosion Resistance Improved by Altering Microstructure. Steel is subject to accelerated wear in a corrosive environment. Unprotected steel is also susceptible to fretting damage or the formation of oxidized wear debris between two contacting surfaces in low-amplitude oscillating motion. A wide variety of microstructures is possible in the heat treatment of steel or cast iron. Wear properties can be related to specific microstructures. Steel Selection Based on Relative Costs When selecting a steel based on its wear-resistance properties, the total cost of the steel and its heat treatment must be considered. The following steels, which may have suitable wear-resistance properties in specific applications, are listed in order of increasing total costs: • Low-carbon steels, such as 1020, not heat treated • Simple high-carbon steels, such as 1095, not heat treated • Directly hardened carbon or low-alloy steels, either through-hardened or surface- hardened by induction or flame process • Low-carbon or low-alloy steels that are surface-hardened by carburizing, cyaniding, or carbonitriding • Medium-carbon chromium or chromium-aluminum steels that are hardened by nitriding • Directly hardened high-alloy steels, such as D2 high-carbon high-chromium tool steel (1.50C- 12Cr), that contain particles of free carbide • Precipitation-hardening stainless steels (mainly for applications involving elevated temperatur es and corrosive environments, as well as excessive wear) • Specialty steels produced by powder metallurgy (P/M) or mechanical alloying techniques • Alloy carbides bonded by steel matrices Other ferrous materials, such as high-manganese austenitic steels and various classes of cast irons, are also widely used for wear-resistance applications. Depth of Hardened Regions Skids, grinding rods, chute liners, and similar parts may be considerably reduced in section before replacement is necessary. In such parts, a more expensive deep-hardening steel may be more economical than a shallow-hardening steel. For example, a 64 mm (2 in.) diameter bar with a surface hardened of 50 HRC may be made of either a water-quenched 1040 or an oil-quenched 5160 steel. However, by the time the bar has been worn to three-fourths of its original diameter ( 48 mm, or 1 in.), the 1040 steel will have a surface hardness of 25 HRC and thus would wear at a much faster rate than the 5160 steel, which has a hardness of 37 HRC at the same location (Ref 2). Toughness Wear resistance tends to increase with hardness, but it decreases as toughness increases. This is an important relationship in applications that require both wear resistance and impact resistance. The correlation between wear resistance and toughness for a variety of ferrous alloys is shown in Fig. 5. The scatter arises, at least in part, from microstructural effects. For example, point 22B refers to AISI 4340 steel, quenched and tempered at a high temperature of 650 °C ( 1200 °F) to produce fine carbides in a ferrite matrix. Point 22A represents the same steel, except normalized to produce fine pearlite; point 22C represents a quenched sample tempered at 205 °C (400 °F), a relatively low tempering temperature. Steels in the lower band of Fig. 5 combine toughness with wear resistance; these are mainly the austenitic manganese steels. The data in Fig. 5 indicate that, for most ferrous alloys, there is a trade-off between wear resistance and toughness. In some alloys, altering the carbon content is a simple method for adjusting these properties. Fig. 5 Relationship between resistance to gouging abrasion and toughness of selected materials. Area A, wrought and cast low-alloy steels; area B, austenitic manganese steels; area C, variety of heat-treated steels; area D, high-chromium white cast irons. Source: Ref 3 Carbon Content The wear resistance of ferritic steel is improved by hardening, either throughout the section or superficially. The maximum hardness depends on the carbon content of the steel and the amount of martensite (that is, efficiency of quenching) (Fig. 2) Standard hardness measurements may indicate that a martensitic steel is largely transformed, although it may retain some austenite. Exposure to ultralow temperatures, followed by tempering, can help complete the transformation to martensite and improve wear resistance. Because martensite is a metastable structure, it begins to transform to more stable structures as the temperature is increased. Consequently, martensitic steels are not suitable for wear resistance at elevated temperatures (>200 °C, or 390 °F) or for applications in which the heat of friction can raise the temperature significantly. Special alloy steels, such as tool steels or martensitic stainless steels, are appropriate for service at higher temperatures. The thermal instability of martensite should also be considered during finishing operations (such as grinding) when a heat-affected zone (HAZ) could be produced at the surface. The resultant tempering effects could be localized or general; in either case, wear resistance is likely to be reduced. Carbon content also affects hardness and wear resistance through the formation of various simple and complex carbides. Wear properties depend on the type, amount, shape, size, and distribution of carbides present, in addition to the properties of the matrix (for example, hardness, toughness, and stability). Despite this complexity, a correlation for relative wear content is possible. Relation of Hardness to Microstructure The frequent use of bulk hardness as a guide to abrasive wear resistance is supported by the data shown in Fig. 6 for annealed unalloyed metals. These data were obtained using an abrasive cloth (two-body abrasion) with an abrasive hardness much greater than that of the metal samples. The data points are approximate; the experimental scatter of the measurements is not shown. Fig. 6 Abrasive wear resistance versus hardness for annealed unalloyed metals and steel. Source: Ref 4 Corresponding correlations with other properties related to hardness (such as elastic modulus) have also been presented. In all cases, if the metals are unalloyed, a simple correlation is obtained for controlled tests of two-body abrasion. Different crystal structures would be expected to yield different correlations, but the data in Fig. 6 do not show such an effect. Care must be exercised in extending the simple hardness correlation to metals containing impurities or solutes, or to more complicated alloys. Figure 7 shows how wear resistance relates to hardness for various types of materials. The linear plot shown for pure metals in Fig. 6 is repeated as the steep line in Fig. 7. Another straight line describes brittle ceramics reasonably well. The differences in bonding type may account for these two distinct lines. [...]... as riveted joints This type of wear is a combination of oxidation and abrasive wear Oscillation of two metallic surfaces produces tiny metallic fragments that oxidize and become abrasive Subsequent wear proceeds by mild adhesive wear in combination with abrasive wear Fretting wear is influenced by contact conditions, environmental conditions, and material properties and behavior These factors may interact... resulting in low wear rates This form of wear is called mild wear, or oxidative wear, and can be tolerated by most moving components When the applied load is high, metallic bonds will form between the surface asperities, and the resulting wear rates are high The load at which there is a transition from mild to severe wear is called the transition load Adhesive wear is more prevalent in parts where a lubricant... titanium alloys tend to gall Factors Affecting Wear and Galling The factors that affect wear and galling can be design, lubrication, environmental, and material related Component design is probably the most critical factor When stainless steels are required, proper design can minimize galling and wear Similar applications, like valve parts, can often result in wear- related problems for one company or be... Abrasive Wear, Wear, Vol 28, 1974, p 97-99 5 E Hornbogen, The Role of Fracture Toughness in the Wear of Metals, Wear, Vol 33, 1975, p 251-259 6 K.H Zum Gahr, Abrasive Wear of Metallic Materials, Metallurgical Aspects of Wear, DGM, 1981, p 73- 104 7 P Clayton, The Relationship between Wear Behavior and Basic Material Properties for Pearlitic Steels, Proceedings of the International Conference on Wear of... 11.5013.00 11.5013.00 11.5013.00 12. 0014.00 12. 0014.00 12. 0014.00 12. 0014.00 13.5015.00 12. 0014.00 1.252.50 0.60 0.60 0.15 min Se 0.251.00 0.401.00 0.60 S40900 409 0.08 1.00 1.00 0.045 0.045 S43000 430 0 .12 1.00 1.00 0.040 0.030 S43020 430F 0 .12 1.25 1.00 0.060 0.1(a) S43023 430FSe 0 .12 1.25 1.00 0.060 0.060 S43400 434 0 .12 1.00 1.00 0.040 0.030 S44200 442... HRC 31 HRC 1620 120 7 793 235 175 115 1689 1310 965 245 190 140 10.0 15.0 12. 0 45.0 55.0 50.0 12 47 9 35 44 HRC 33 HRC 126 2 869 183 126 1365 1131 198 164 15.0 17.0 52.0 59.0 21 75 16 55 Annealed Oil quenched from 816 °C (1500 °F) and tempered at 204 °C (400 °F) 97 HRB 42 HRC 455 980 66 142 821 1304 119 189 15.0 12. 0 22.0 35.0 Annealed Aged 56 HRB 55 276 8 40 124 311 18 45 25.0 12. 0 Annealed... Stainless steels are characterized as having relatively poor wear and galling resistance, but are often required for a particular application, because of their corrosion resistance Therefore, finding the most effective alloy to withstand wear and galling can be a difficult problem for design engineers Lubricants and coatings are often used to reduce wear, although lubricant use is precluded in may applications,... or food and pharmaceutical processing equipment, which require sanitation Additionally, a critical part, such as a valve in a power plant, must resist galling or seizing, because it can shut down or endanger the entire plant (Ref 1, 2) This article discusses each stainless steel family, specifically in terms of wear resistance Information on wear and galling, laboratory wear and galling tests, and the... Source: Ref 6 References 1 G Krauss, Physical Metallurgy and Heat Treatment of Steel, Metals Handbook Desk Edition, H.E Boyer and T.L Gall, Ed., American Society for Metals, 1985, p 28-2 to 28-10 2 Properties and Selection of Irons and Steels, Vol 1, 9th ed., Metals Handbook, 1978, p 606 3 D.E Diesburg and F Borik, Optimizing Abrasion Resistance and Toughness in Steels for the Mining Industry, Symposium... ductility and toughness The most commonly used alloy in this family is S41000, which contains about 12% Cr and 0.1% C This alloy is tempered to a variety of hardness levels, from 20 to 40 HRC Both chromium and carbon contents are increased in alloys S42000, S44002, S44003, and S44004 The first of these contains 14% Cr and 0.3% C and has a hardness capability of 50 HRC The other three alloys contain 16% Cr and . specifically in terms of wear resistance. Information on wear and galling, laboratory wear and galling tests, and the associated data from these tests is presented. Applications and design considerations. . . . . . . . . . . . . 12Mn- 1Mo 0.97 12. 5 0.5 . . . . . . 0.94 . . . . . . . . . . . . 12Mn 1.1 12. 5 0.5 . . . . . . . . . . . . . . . . . . . . . 12Mn 1.24 12. 5 0.5 . . . . . . 0.05. . . . . . . . 12Mn- 1Mo-Ti 1.26 12. 5 0.5 . . . . . . 0.96 . . . . . . 0.25Ti . . . 12Mn- 1Mo-Ti 1.29 12. 5 0.5 . . . . . . 0.94 . . . . . . 0.018Ti . . . 12Mn- 1Mo-Ti 1.29 12. 5 0.5 . . .