Volume 09 - Metallography and Microstructures Part 6 ppt

Fig. 67 AISI M2. Heat treated at 1220 °C (2225 °F) for 5 min in salt, oil quench, 1175 °C (2150 °F) for 5 min in salt, oil quench. 64 HRC. Grain growth due to rehardening without annealing between heat treatments. 10% nital. 400× Fig. 68 AISI M2. Heat treated at 1260 °C (2300 °F) for 5 min in salt, oil quench, double tempered at 540 °C (1000 °F). 66 HRC. Overaustenitization and onset of grain boundary melting (arrow). 3% nital/Vilella's reagent. 1000× Fig. 69 AISI S5 austenitized and isothermally transformed at 650 °C (1200 °F) for 4 h (air cooled) to form ferrite and coarse pearlite. 23 to 24 HRC. 4% picral. 1000× Fig. 70 AISI S5 austenitized, isothermally transformed at 595 °C (1100 °F) for 8 h and air cooled to form ferrite and fine pearlite. 36 HRC. 4% picral. 1000× Fig. 71 AISI S5 austenitized, isothermally transformed (partially) at 540 °C (1000 °F ) for 8 h, and water quenched to form upper bainite (dark); balance of austenite formed martensite. 4% picral/2% nital. 1000× Fig. 72 AISI S5 austenitized, isothermally transformed at 400 °C (750 °F) for 1 h, and air cooled to form lower bainite. 37 to 38 HRC. 4% picral/2% nital. 1000×. Fig. 73 Fig. 74 Fig. 75 AISI S7. Continuous cooling transformations. Some very fine undissolved carbide is present in all specimens in this series. Fig. 73: austenitized at 940 °C (1725 °F) and cooled at 2780 °C/h (5000 °F/h). 62 HRC. Structure is martensite plus a small amount of bainite. Fig. 74: cooled at 1390 °C/h (2500 °F/h) to produce a greater amount of bainite. 61.5 HRC. Fig. 75: cooled at 830 °C/h (1500 °F/h). 56.5 HRC. Structure is mostly bainite plus some martensite (light). 4% picral. 500× Fig. 76 Fig. 77 Fig. 78 AISI S7. Continuous cooling transformations. Some very fine carbide is present in all specimens in this series. Fig. 76: austenitized at 940 °C (1725 °F) and cooled at 445 °C/h (800 °F/h). 51.5 HRC. Structure is nearly all bainite with some small patches of martensite (white). Fig. 77: cooled at 220 h (400 °F/h). 45 HRC. Structure is mostly bainite with fine pearlite at the prior-austenite grain boundaries. Fig. 78: cooled at 28 °C/h (50 °F/h) to 620 °C (1150 °F), then water quenched. Austenite present at 620 °C (1150 °F) was transformed to martensite. Structure is mostly fine pearlite with patches of martensite (white). See also Fig. 73, 74, and 75. 4% picral. 500× Fig. 79 Fig. 80 Fig. 81 Fig. 82 AISI O1. Influence of tempering temperature. All specimens austenitized at 800 °C (1475 °F), oil quenched, and tempered at different temperatures. Fig. 79: 200 °C (400 °F). 60 HRC. Fig. 80: 315 °C (600 °F). 55 HRC. Fig. 81: 425 °C (800 °F). 49 HRC. Fig. 82: 540 °C (1000 °F). 43 HRC. 4% picral. 500× Fig. 85 Fig. 83 Fig. 84 AISI W1. Austenitized at 800 °C (1475 °F), brine quenched, and tempered 2 h at 150 °C (300 °F). Black rings are hardened zones in 75-, 50-, and 25-mm (3-, 2-, and 1 -in.) diam bars. Core hardness decreases with increasing bar diameter. Fig. 83: shallow-hardening grade. Case, 65 HRC; core, 34 to 43 HRC. Fig. 84: medium-hardening grade. Case, 64.5 HRC: core, 36 to 41 HRC. Fig. 85: deep-hardening grade. Case, 65 HRC; core, 36.5 to 45 HRC. Hot 50% HCl. One half actual size. Fig. 86 Fig. 87 Fig. 88 Fig. 89 AISI W1 (1.05% C), 19-mm (0.75-in.) diam bars; brine quenched. Fig. 86: hardened case microstructure. 64 HRC. Case contains as-quenched martensite and undissolved carbides. 4% picral. Fig. 87: 2% nital etch reveals martensite as dark rather than light. Fig. 88: transition zone. 55 HRC. Martensite is light, undissolved, carbide is outlined, and pearlite is dark. 4% picral. Fig. 89: core microstructure. 42 to 44 HRC. 4% picral etch reveals fine pearlite matrix (black) containing some patches of martensite (white) and undissolved carbides (outlined white particles). 1000× Fig. 90 Fig. 91 Fig. 92 AISI F2, heated to 870 °C (1600 °F), water quenched, and tempered at 150 °C (300 °F). Fig. 90: case microstructure. 63 HRC. 2% nital. Fig. 91: transition region. Martensite (light) and pearlite (dark) are present between the surface and center. 4% picral. Fig. 92: core microstructure. 48 HRC. 4% picral etch reveals pearlite, carbides, and some martensite. 1000× Fig. 93 Fig. 94 Fig. 95 Fig. 96 AISI S2, heated to 845 °C (1550 °F), water quenched, and tempered at 150 °C (300 °F). Fig. 93: 59.5 HRC. Structure consists of martensite and some very fine undissolved carbide. 2% nital. 1000×. Fig. 94: surface of part that was decarburized, then carburized and heat treated. Note white ferrite grains below the dark surface layer. 3% nital. 200×. Fig. 95: as in Fig. 94, but at 400×. Ferrite at 260 HK, martensite in surface layer at 665 HK, martensite beneath ferrite increased from 400 to 635 HK going away from ferrite. Fig. 96: core structure. 580 HK. Martensite (dark), some undissolved carbides and ferrite (white) formed during quenching. 3% nital. 1000× Fig. 97 AISI L6, heated to 840 °C (1550 °F), oil quenched and tempered at 150 °C (300 °F). 61 HRC. Martensite and undissolved carbides are revealed. 2% nital. 1000× Fig. 98 AISI O2, heated to 850 °C (1500 °F), oil quenched and tempered at 175 °C (350 °F). 61 HRC. Martensite and a small amount of undissolved carbide are revealed. 2% nital. 1000× Fig. 99 AISI S1, heated to 955 °C ( 1750 °F), oil quenched and tempered at 150 °C (300 °F). 58 to 59 HRC. Only martensite is visible. 2% nital. 500× Fig. 100 AISI S5, heated to 870 °C (1600 °F) and oil quenched. 62 HRC. Only martensite is visible. 4% picral/2% nital. 1000× Fig. 101 AISI S5 heated to 870 °C (1600 °F), oil quenched and tempered at 175 °C (350 °F). 60 HRC. Only martensite is visible. 2% nital. 1000× Fig. 102 AISI S5 heated to 870 °C (1600 °F), oil quenched and tempered at 480 °C (900 °F). 51 to 52 HRC. Only martensite is visible. 2% nital. 1000× Fig. 103 AI SI S7, heated to 940 °C (1725 °F), air quenched and tempered at 200 °C (400 °F). 58 HRC. Martensite and a small amount of undissolved carbides are observed. Vilella's reagent. 1000× Fig. 104 AISI S7 heated to 940 °C (1725 °F), air quenched and tempered at 495 °C (925 °F). 52 HRC. Martensite and a small amount of undissolved carbide are observed. Vilella's reagent. 1000× Fig. 105 AISI P20 heated to 900 °C (1650 °F), water quenched and tempered at 525 °C (975 °F). 32 HRC. Matrix is martensite. Dark particles are manganese sulfides. Contrast process orthochromatic film. 2% nital. 500× Fig. 106 Fig. 107 Fig. 108 AISI P5, heat treated. Case, 59.5 HRC; core, 22 HRC. Fig. 106: carburized case. Note the carbide enrichment and networking in the case region. Matrix is martensite. 100×. Fig. 107: carburized case microstructure. 1000×. Fig. 108: differential interference contrast micrograph, core microstructure. Austenitization temperature used to harden the case is too low for the core; note the ferrite (white) and martensite (dark) in the underaustenitized core. 2% nital. 400× Fig. 109 AISI A 6, heated to 840 °C (1550 °F), air quenched and tempered at 150 °C (300 °F). 61.5 HRC. Martensite plus a small amount of undissolved carbide are observed. 2% nital. 1000× Fig. 110 AISI H11, heated to 1010 °C (1850 °F), air quenched and double tempered at 510 °C (950 °F). 52 HRC. Martensite plus a small amount of very fine carbide are visible. Vilello's reagent. 1000× Fig. 111 AISI H13, heated to 1025 °C (1875 °F), air quenched and double tempered at 595 °C (1100 °F). 42 HRC. All martensite plus a small amount of very fine undissolved carbide. 2% nital. 1000× Fig. 112 AISI H21, heated to 1200 °C (2200 °F), oil quenched and t empered at 595 °C (1100 °F). 53.5 HRC. Martensite and undissolved carbide are observed. 2% nital/Vilella's reagent. 1000× Fig. 113 AISI D2, heated to 1010 °C (1850 °F), air quenched and tempered at 200 °C (400 °F). 59.5 HRC. Martensite plus substantial undissolved carbide; note the prior-austenite grain boundaries. 2% nital. 1000× Fig. 114 AISI D3, heated to 980 °C (1800 °F), oil, quenched and tempered at 200 °C (400 °F). 60.5 HRC. Martensite plus substantial undissolved carbide are visible. 2% nital/Vilella's reagent. 1000× Fig. 115 AISI Ml, heated to 1175 °C (2150 °F), oil quenched and triple tempered at 480 °C (900 °F). 62 HRC. Martensite plus undissolved carbide are revealed. 2% nital. 1000× [...]... grades 63 0 (1 7-4 PH) 0.07 15.5 0-1 7.50 3. 0-5 .0 1.0 1.0 0.040 0.030 3. 0-3 .5Cu, 0.1 5-0 .45Nb + Ta 63 1 (1 7-7 PH) 0 .09 16. 0 0-1 8.00 6. 5-7 .75 1.0 1.0 0.040 0.030 0.7 5-1 .50Al 63 3 (AM-350) 0.070.11 16. 0 0-1 7.00 4.0 0-5 .00 0. 5-1 .25 0.5 0.040 0.030 2. 5-3 .25Mo, 0.0 7-0 .13N 63 4 (AM355) 0.100.15 15.0 0-1 6. 00 4.0 0-5 .00 0. 5-1 .25 0.5 0.040 0.030 2. 5-3 .25Mo 63 5 W) 0.08 16. 0 0-1 7.50 6. 0 0-7 .50 1.0 1.0 0.040 0.030 0.4Al, 0. 4-1 .2... 0.03 16. 0 0-1 8.00 10.0 0-1 4.00 2.0 0.75 0.045 0.030 2. 0-3 .0Mo, 0.10N Austenitic grades 321 0.08 17.0 0-1 9.00 9.0 0-1 2.00 2.0 1.0 0.045 0.030 0.10N, 5 × C + N min Ti 20Cb-3 0.07 19.0 0-2 1.00 32.0 0-3 8.00 2.0 1.0 0.045 0.035 2. 0-3 .0Mo, 3. 0-4 .0Cu 8 × C min Nb (1.0 max) 2 2-1 3-5 0. 06 20. 5-2 3.5 11. 5-1 3.5 4. 0 -6 .0 1.0 0.040 0.030 1. 5-3 .0Mo, 0. 2-0 .4N, 0. 1-0 .3Nb, 0. 1-0 .3V 409 0.08 10.5 0-1 1.75 1.0 1.0 0.045 0.045 6 ×... 0.15 16. 0 0-1 8.00 6. 0 0-8 .00 2.0 1.0 0.045 0.030 302 0.15 17.0 0-1 9.00 8.0 0-1 0.00 2.0 1.0 0.045 0.030 303 0.15 17.0 0-1 9.00 8.0 0-1 0.00 2.0 1.0 0.20 0.15 min 0 .60 Mo(b) 304 0.08 18.0 0-2 0.00 8.0 0-1 0.00 2.0 1.0 0.045 0.030 0.10N 308 0.08 19.0 0-2 1.00 10.0 0-1 2.00 2.0 1.0 0.045 0.030 310 0.25 24.0 0-2 6. 00 19.0 0-2 2.00 2.0 1.5 0.045 0.030 3 16 0.08 16. 0 0-1 8.00 10.0 0-1 4.00 2.0 1.0 0.045 0.030 2. 0-3 .0Mo, 0.10N 316L... 0.030 0.4Al, 0. 4-1 .2 Ti 1 5-5 PH 0.07 14.0 0-1 5.5 3. 5-5 .5 1.0 1.0 0.040 0.030 2. 5-4 .5Cu, 0.1 5-0 .45Nb + Ta PH1 3-8 Mo 0.05 12.2 5-1 3.25 7. 5-8 .5 0.10 0.10 0.010 0.008 2. 0-2 .5Mo, 0.9 0-1 .35Al, 0.01N Custom 450 0.05 14.0 0-1 6. 00 5. 0-7 .0 1.0 1.0 0.030 0.030 1.2 5-1 .75Cu, 0. 5-1 .0Mo, 8 × C min Nb (1.0 max) Custom 455 0.05 11.0 0-1 2.50 7. 5-9 .5 0.5 0.5 0.040 0.030 0.5Mo, 1. 5-2 .5Cu, 0. 8-1 .4Ti, 0. 1-0 .5Nb 30.0 (nominal) 9.0... 0.030 4 16 0.15 12.0 0-1 4.00 1.25 1.0 0. 060 0.15 min 0 .60 Mo(b) 420 0.15 min 12.0 0-1 4.00 1.0 1.0 0.040 0.030 420F 0.15 min 12.0 0-1 4.00 1.25 1.0 0. 060 0.15 min 0 .60 Mo(b) 431 0.20 15.0 0-1 7.00 1.2 5-2 .50 1.0 1.0 0.040 0.030 440A 0 .60 0.75 16. 0 0-1 8.00 1.0 1.0 0.040 0.030 0.75Mo 440B 0.750.95 16. 0 0-1 8.00 1.0 1.0 0.040 0.030 0.75Mo 440C 0.951.20 16. 0 0-1 8.00 1.0 1.0 0.040 0.030 0.75Mo Precipitation-hardenable... at 0. 5-1 .5 A/cm2 (3. 2-9 .7 A/in.2), 20 °C (70 °F) max 3 62 mL HClO4, 700 mL ethanol, 100 mL butyl cellusolve, 137 mL H2O Add HClO4 last, with care Use at 1.2 A/cm2 (7.7 A/in.2), 20 °C (70 °F), 2 0-2 5 s 4 25 g CrO3, 133 mL acetic acid, 7 mL H2O Use at 20 V dc, 0 .0 9- 0.22 A/cm2 (0.5 8-1 .4 A/in.2), 1 7-1 9 °C (6 3 -6 6 °F), 6 min Dissolve CrO3 in solution heated to 6 0-7 0 °C (14 0-1 60 °F) 5 37 mL H3PO4, 56 mL glycerol,... quantitative metallography of cemented carbides is presented in Ref 8 and 9 The important parameters to be measured are pore volume, binder volume fraction, binder-mean free path, carbide grain size and shape, and the contiguity, which is the particle-to-particle grain-boundary ratio to total surface area Using well-established stereo-logical techniques, microstructural parameters such as the volume fraction... max) 430 0.12 16. 0 0-1 8.00 1.0 1.0 0.040 0.030 430F 0.12 16. 0 0-1 8.00 1.25 1.0 0.040 0. 060 0 .60 Mo(b) 4 46 0.20 23.0 0-2 7.00 1.5 1.0 0.040 0.030 0.25N 182-FM 0.08 17.5 0-1 9.50 2.5 1.0 0.040 0.15 min E-Brite 0.01 25. 0-2 7.5 0.50 0.40 0.40 0.020 0.020 0.7 5-1 .5Mo, 0.015N, 0.2 max Cu (0.5 max Cu + Ni) Ferritic grades Martensitic grades 403 0.15 11.5 0-1 3.00 1.0 0.5 0.040 0.030 410 0.15 11.5 0-1 3.50 1.0 1.0... use at 1.1 V dc, 0.07 5-0 .14 A/cm2 (0.4 8-0 .90 A/in.2), 120 s With platinum cathode, use at 0.4 V dc, 0.05 5-0 . 066 A/cm2 (0.3 5-0 .43 A/in.2), 45 s Will reveal prior-austenite grain boundaries in solution-treated (but not aged) martensitic precipitation-hardenable alloys 17 50 g NaOH and 100 mL H2O Electrolytic etch at 2 -6 V dc, 5-1 0 s to reveal σ phase in austenitic grades 18 56 g KOH and 100 mL H2O Electrolytic... Quantitative Metallography, STP 839, J.L McCall and J.H Steele, Jr., Ed., ASTM, Philadelphia, 1984, p 65 84 10 H Grewe, Structural Investigation on Hard Metals, Prakt Metallog., Vol 5, 1 969 , p 41 1-4 19 11 W Mader and K.F Muller, Determination and Comparison of Structural Parameters of Hard Metal Alloys Using Electron and Optical Micrographs, Prakt Metallog., Vol 5, 1 968 , p 61 6- 6 25 12 W Peter, E Kohlhaas, and . fraction, binder-mean free path, carbide grain size and shape, and the contiguity, which is the particle-to-particle grain-boundary ratio to total surface area. Using well-established stereo-logical. 25-mm (1-in.) diam or four 38-mm (1.5-in.) diam specimens simultaneously. The initial grinding and flattening takes I to 2 min using a 220-grit resin-bonded diamond lap. Scratches and work-hardened. Austenitized at 800 °C (1475 °F), brine quenched, and tempered 2 h at 150 °C (300 °F). Black rings are hardened zones in 7 5-, 5 0-, and 25-mm ( 3-, 2-, and 1 -in.) diam bars. Core hardness decreases with