Volume 09 - Metallography and Microstructures Part 13 potx

Fig. 13 Same material, thickness, cold reduction, and annealing as Fig. 12 , then temper rolled (10% additional reduction). Ferrite grains are slightly elongated; some compression is evident at the surface. 3% nital. 100× Fig. 14 Same material, thickness, cold reduction, annealing, and temper-rolling reduction as Fig. 11 , but heated to 940 °C (1725 °F) and held 2 min. The recrystallized ferrite grains are very large. 3% nital. 100× Fig. 15 Same material, thickness, cold reduction, annealing, and temper-rolling treatment as Fig. 13 , but reheated to 940 °C (1725 °F) and held 2 min. Structure: large recrystallized ferrite grains. 3% nital. 100× Fig. 16 3% Si flat-rolled electrical strip (M- 22), cold rolled 70% to 0.6 mm (0.025 in.) thick. Structure is ferrite grains elongated in the direction of rolling. See also Fig. 17. 10% nital. 100× Fig. 17 Same material, thickness, and cold reduction as Fig. 16 , decarburization annealed in moist hydrogen at 815 °C (1500 °F) and annealed for grain growth in dry hydrogen at 870 °C (1600 °F). Compare with Fig. 18 . 10% nital. 100× Fig. 18 3% Si flat-rolled electrical strip (M-22), cold rolled to ~0.6- mm (0.023 in.) (70% reduction), decarburization annealed in moist hydrogen at 815 °C (1500 °F), and annealed in dry hydrogen at 925 °C (1700 °F) for grain growth. Note large ferrite grain size. 10% nital. 100× Fig. 19 3.25% Si cold- rolled electrical strip, 0.3 mm (0.011 in.) thick, annealed at 1175 °C (2150 °F), showing domain structure of (110) [001] oriented materia l with no applied field. The specimen was demagnetized at 60 Hz. Domains reveal where the deviation of [001] direction is not more than 3 or 4° from parallel. As- polished. Magnification not reported Fig. 20 3% Si flat- rolled electrical strip, cold reduced 70% to approximately 0.6 mm (0.025 in.) thick, decarburization annealed in moist hydrogen at 815 °C (1500 °F) and at 1040 °C (1900 °F) in dry hydrogen for grain growth. The ferrite grain size is larger than in Fig. 17 and 18. 10% nital. 100× Fig. 21 3% Si flat- rolled, oriented electrical hot band, as hot rolled. Cross section from near the surface (right) to a depth of approximately 0.5 mm (0.02 in.). Hot finishing temperature was approximately 900 °C (1650 °F). The structure is ferrite grains; note difference in grain shape from near surface to near center. 10% nital. 100× Fig. 22 3% Si flat-rolled orie nted electrical strip, cold reduced 65% and annealed at 925 °C (1700 °F). Structure: recrystallized ferrite grains. The material is ready for final cold reduction and a grain- coarsening anneal. See also Fig. 23 and 24 for effects of further processing. 10% nital. 100× Fig. 23 Same material as Fig. 22 , but given a second cold reduction of 50% to final strip thickness. Ferrite grains are elongated, ready for the grain-coarsening anneal. See also Fig. 24. 10% nital. 100× Fig. 24 Same material and reduction as Fig. 23 after a grain- coarsening box anneal at 1095 to 1205 °C (2000 to 2200 °F) in hydrogen. The upper strip shows portions of two grains; the lower strip, one complete and two partial grains. 10% nital. 100× Fig. 25 3.25% Si flat- rolled, oriented electrical strip, continuously cold rolled to 0.3 mm (0.011 in.) thick, annealed at 1175 °C (2150 °F). Macrograph shows secondary recrystallized ferrite grains with cube-on- edge orientation. 5 mL HCl, 1 mL HF, and 8 mL H 2 O. Actual size Fig. 26 3% Si steel, 0.35 mm (0.014 in.) thick, gradient annealed by heating to 760 °C (1400 °F) in 1 h, then at 65 °C (100 °F) per hour to 1065 °C (1950 °F) at hot end (right) in dry hydrogen and held 3 h. Secondary grain coarsening started at approximately 815 °C (1500 °F). Grain size is typical. 20% HNO 3 , then 20% HCl (alternated). Actual size Fig. 27 3% Si Steel, hot rolled to 0.35 mm (0.014 in.) thick, annealed 24 h at 1150 °C (2100 °F) in dry hydrogen. Note fine, poorly oriented grains, which are parallel to the rolling direction, in a matrix of normal, well-oriented grains. This can result from stringers of inclusions or from rolled-in scale. 5% HF, then 10% HNO 3 . Actual size Fig. 28 3% Si steel, 0.3 mm (0.012 in.) thick, annealed 7.5 h in dry hydrogen at 1175 °C (2100 °F). Specimen shows abnormally small grain size, which indicates poo r orientation. This may be caused by the wrong percentage of cold reduction or by heating too rapidly above 1010 °C (1850 °F). 20% HNO 3 , then 20% HCI (alternated). Actual size Fig. 29 Cubic etch pits in cube-on-face grain- oriented 3% Si steel. The area seen is a single ferrite grain, obtained by annealing at 1175 °C (2150 °F) or higher. Fe 2 (SO 4 ) 3 . 1000× Fig. 30 Scanning electron micrograph of cubic etch pits in cube-on-face grain- oriented 3% Si steel. The area shown is a single grain of ferrite. See also Fig. 29 and 31. Fe 2 (SO 4 ) 3 . 1000× Fig. 31 Etch Pits in a 3% Si steel, showing two orientations. The hexagonal pits have cube-on- corner orientation; the others have cube-on-edge orientations. Fe 2 (SO 4 ) 3 . 1000× Fig. 32 Thermal faceting and pitting of (100) planes of ferrite in 3% Si grain- oriented steel, cold rolled from 0.3 to 0.1 mm thick and annealed 3 h in dry hydrogen at 1205 °C (2200 °F). Thermal etch in hydrogen at 1205 °C (2200 °F).100× Fig. 33 Solenoid- quality type 430FR ferritic stainless steel. Note that some of the ferrite grain boundaries were not revealed. Ralph's reagent. 100× Fig. 34 Fe-30Ni cold- rolled strip, batch annealed 6 h at 950 °C (1740 °F) and furnace cooled in dry hydrogen. Grains are coarse because carbon content was low. HCl, CuCl 2 , FeCl 3 , HNO 3 , methanol, and H 2 O. 100× Fig. 35 Fig. 36 Austenitic Fe-50.5Ni soft magnetic alloy, showing the effects of different etchants. Fig. 35: etched using a flat etchant, glyceregia. Fig. 36: etched using a grain contrast etchant, Marble's reagent. Both 100×. See Fig. 37, 38, 39 for the effects of deformation (cold rolling) and heat treatment on the structure of a similar Fe-50Ni alloy. Fig. 37 Fe-50Ni cold-rolled 0.15-mm strip, annealed 2 h in H 2 at 900 °C and furnace cooled. Structure: primary recrystallized grains of austenite. 60 mL ethanol, 15 mL HCl, and 5 g anhydrous FeCl 3 . 100× Fig. 38 Fe-50Ni cold-rolled 0.03-mm strip, annealed 4 h at 1175 °C (2150 °F) in dry H 2 and furnace cooled. Structure is nonoriented primary recrystallized grains. See also Fig. 39. Saturated (NH 4 ) 2 S 2 O 8 . 100× Fig. 39 Fe-50Ni cold-rolled strip, 0.03 mm (0.014 in.) thick, annealed same as Fig. 38. The structure is comprised of nonoriented secondary recrystallized grains. Thermal etch in hydrogen at 1175 °C (2150 °F). 3× Fig. 40 4-79 Moly Permalloy (4Mo-79Ni-17Fe), cold- rolled strip 0.03 mm (0.014 in.) thick, annealed 4 h in dry hydrogen at 1175 °C (2150 °F) and cooled at 320 °C (575 °F) per hour to room temperature. The structure is coarse-grained austenite. HCl, CuCl 2 , FeCl 3 , HNO 3 , methanol, and H 2 O. 100× Fig. 41 4-79 Moly Permalloy magnetic test-ring specimen taken from 0.3-mm (0.014-in.) thick cold- rolled strip, annealed 4.5 h at 1120 °C (2050 °F) in dry hydrogen. The structure is austenite grains. Marble's reagent. 0.875× Fig. 42 Fe-27Co cold-rolled strip, annealed 2 h in dry H 2 at 925 °C (1700 °F) and furnace cooled. The microstructure is ferrite solid solution. HCl, CuCl 2 , FeCl 3 , methanol, and H 2 O. 100× Fig. 43 Fe-Co-1.9V alloy, annealed 2 h in wet hydrogen at 885 °C (1625 °F). A duplex ferritic grain structure. 2% nital. 50× Fig. 44 Fig. 45 Remendur 27 (Fe-Co-2.8V) wire, 0.5 mm (0.021 in.) in diameter. Structure: α 1 and α 2 phases. Fig. 44: bright-field illumination. Fig. 45: differential interference contrast illumination. 2% nital etches α 1 leaving α 2 in relief. Both 1000× [...]... 3. 5-4 .5 3. 5-4 .5 1. 5-4 .0 0.10 0.20 19, 20, 30, and 31 SAE 792 77.0 min 9. 0-1 1.0 9. 0-1 1.0 0.7 0.50 0.50 0.7 0.40 17, and 18 SAE 793 83.0 min 7. 0-9 .0 3. 5-4 .5 0.5(h) 0.50 0.50 0.7 0.30 23 72. 0-7 6.0 14. 0-1 8.0 9. 0-1 1.0 0.5 0.50 0.50 0.7 0.30 24, 25, 26, 27, 28, and 32 SAE 794 68. 5-7 5.5 21. 0-2 5.0 3. 0-4 .0 0.5(h) 0.50 0.50 0.7 0.40 22 SAE 795 88. 0-9 2.0(i) 0.2 5-0 .7 rem 0.10 0.20 41 88. 0-9 2.0(i) 9. 5-1 0.5... rem 8. 0-1 2.0 0.5 42, 43, 44, 45, 46, 51, 52, 53, 54, 55, 56, and 57 SAE 192 rem 8. 0-1 2.0 1. 0-3 .0 0.5 38, and 39 SAE 193 rem 16. 0-2 0.0 2. 0-3 .0 0.5 83, and 84 SAE 194 rem 5. 0-1 0.0 0.5 Fig Alloy designation Composition, %(a) Cu Pb Sn Ag Zn P Fe Others (total) Others (each) Copper-lead(c) 15, and 16 SAE 48 67. 0-7 4.0 26. 0-3 3.0 0.5 1.5 0.10 0.02 0.7 0.15 12, 13, 14, and 33 SAE 49 73. 0-7 9.0 21. 0-2 7.0... 7, and 8 SAE 13 rem 5. 0-7 .0 9. 0-1 1.0 0.7 0.25 0.10 0.005 0.005 0.05 0.02 3, 4, and 5 SAE 14 rem 9. 0-1 1.0 14. 0-1 6.0 0.7 0.6 0.10 0.005 0.005 0.05 0.02 9, 10, and 11 SAE 15 rem 0. 9-1 .7 13. 5-1 5.5 0.7 0. 8-1 .2 0.10 0.005 0.005 0.02 0.02 40 SAE 16(b) rem 3. 5-4 .7 3. 0-4 .0 0.10 0.05 0.10 0.005 0.005 0.005 0.40 Fig Alloy designation Composition, %(a) designation Pb Sn Cu In Others (total) Plated overlay 36, and. .. 80, and 81 SAE 782 rem 2.73.5 0.30 0. 7-1 .3 0.30 0.71.3 0.15 0.10 64, 65, 66, and 67 SAE 783 rem 17.522.5 0.50 0. 7-1 .3 0.50 0.10 0.15 0.10 68, and 69 SAE 784 rem 0.2 10.012.0 0. 7-1 .3 0.30 0.10 0.03 0.10 70, and 71 SAE 785 rem 0.2 0. 7-1 .3 0. 7-1 .3 0.30 4.55.5 0.30 0.10 72, and 73 SAE 786 rem 37.542.5 0.30 0.30 0.10 74, and 75 SAE 787 rem 0. 5-2 .0 3. 5-4 .5 0.51.0(f) 0.30 4 .09. 0... Trimetal bearing: lead-tin-copper electroplated overlay, copper electroplated barrier, aluminum-silicon-cadmium alloy 5% nital High-tin aluminum alloy clad to nickel-plated steel Lead-base babbitt liner Tin-base babbitt liner Steel backing of any bearing alloy Keller's reagent (a) Lead-tin-copper overlay on aluminum-cadmium alloy Equal parts of concentrated NH4OH and water with 2-4 drops of H2O2 (30%)... material NH4OH and H2O2(a) Commercial bronze liner H2O2(a) Copper-lead alloy liner Copper-lead-tin alloy liner High-leaded tin bronze liner Leaded tin bronze liner Lead-tin-copper overlay on copper-lead alloy liner Nickel bronze infiltrated with lead-base babbitt Nickel-tin bronze infiltrated with lead-base babbitt Silver electroplate on steel Silver-lead alloy electroplate on steel Tin-base babbitt... visible in the microstructures of mixtures containing either element Binary age-hardenable alloys of copper-chromium and copper-beryllium are more resistant to thermal softening than unalloyed copper (see the article "Beryllium-Copper and Beryllium-Nickel Alloys" in this Volume) Several ternary and quaternary alloys, including those that contain cobalt and beryllium, or cobalt, cadmium, and silicon,... 21. 0-2 7.0 0. 6-2 .0 0.7 0.45 34, and 35 SAE 485 rem 44. 0-5 8.0 1. 0-5 .0 0.35 0.45 0.15 Fig Alloy designation Composition, %(a) Al Sn Cd Si Cu Fe Ni Pb Zn Others (total) Others (each) Aluminum base 59 SAE 770 rem 5. 5-7 .0 0.7 0. 7-1 .3 0.7 0.71.3 0.30 0.10 82, 85, 86, and 87 SAE 780 rem 5. 5-7 .0 1. 0-2 .0 0. 7-1 .3 0.7 0.20.7 0.15 0.10 60, 61, 78, and 79 SAE 781(d) rem 0.81.4 3. 5-4 .5 0.050.15... coarser than those in Fig 49 1:1:2 HF, HNO3, and H2O 1000× Fig 51 Macrostructure of Chromindur II (Fe-28Cr-10.5Co) cup-shaped telephone receiver magnets that were deep drawn from 1-mm (0.04-in.) thick strip and solution annealed at (left) 980 °C (1795 °F) and (right) 955 °C (1750 °F) Glyceregia See Fig 52 for a higher magnification view of a deep-drawn and solution-annealed Chromindur II structure A transmission... on copper-lead-tin alloy liner Tin bronze infiltrated with lead-base babbitt Tin bronze infiltrated with Teflon Trimetal bearing: lead-tin-copper electroplated overlay, brass electroplated barrier, copper-lead alloy 0.5% HF Aluminum alloy clad to steel Aluminum-silicon alloy clad to steel High-tin aluminum alloy clad with unalloyed aluminum Lead-tin-copper overlay on aluminum alloy liner Low-tin aluminum . the 600-grit paper in grinding and on the percentage of tungsten in the specimen, rapid rough polishing can begin with 1 5- or 9- m diamond paste and can proceed in steps through 6- and 3- m pastes examples are copper-tungsten and copper-graphite mixtures as well as silver- graphite, silver-cadmium oxide, and silver-nickel combinations. These materials often are examined in the as-polished (not. min. Microstructures of Electrical Contact Materials The electrical contact materials depicted in this article include copper-, silver-, tungsten-, tungsten-carbide-, and molybdenum-base materials,