3.5NI钢物性

Unless otherwise stated this page contains Version 1.0 content (Read more about versions) 2.3.7 Thermal conductivitiesDefinition and unitsThe thermal conductivity, λ, of a substance may be defined as the quantity of heat transmitted, Q, due to unit temperature gradient, in unit time under steady conditions in a direction normal to a surface of unit area, when the heat transfer is dependent only on the temperature gradient.λ = −Q ∂T ∂nIn this section thermal conductivity values are assembled for metallic, semi-conducting and insulating elements, representative groups of alloys, refractories and miscellaneous constructional and insulating materials, some liquids and some gases. The values are expressed in the SI unit W m−1 K−1 throughout. Factors for converting to other units are as follows:1 W m−1 K−1 = 0.01 J cm cm−2 s−1 K−1= 0.002 388 cal cm cm−2 s−1 K−1= 0.859 8 kcal m m−2 h−1 K−1= 0.001 926 Btu in ft−2 s−1 °F−1= 6.933 Btu in ft−2 h−1 °F−1= 0.577 8 Btu ft ft−2 h−1 °F−1= 0.000 160 5 Btu ft ft−2s−1 °F−1More extensive collections of thermal conductivity data will be found in Touloukian et al. (1970a, b and c).Thermal conductivities of metallic elementsThe thermal conductivity values in the table below are for metallic elements in the purest polycrystalline condition for which reliable measurements have been reported. Entries in italics relate to the liquid phase.The thermal conductivities of less pure samples of these elements will be lower than the values given below. Thermal conductivity invariably decreases with decreasing purity; such dependence being weak at ambient and higher temperatures but very strong at cryogenic temperatures.λ/(W m−1 K−1)† Values for the a-axis which approximate to the polycrystal; those for the b-axis are 91 and 88 and for the c-axis are 16.5 and 16 at 173.2 and 273.2 K.Thermal conductivities of single crystals of some non-cubic metals at normal temperatureλ/(W m−1 K−1)Thermal conductivities of alloysAt low temperatures the thermal conductivity of a given metal tends to increase in proportion to the reciprocal of its residual resistivity ρ0. Many metals, especially good electrical conductors, have thermal conductivities that follow the simple relationλ = L0σTat very low temperatures and at temperatures higher than their Debye temperature; L0 being the Lorentz coefficient 2.45 × 10−8 W s−1 K−2, σ the electrical conductivity in S m−1 and T the absolute temperature. This behaviour enables the thermal conductivities of metallic samples to be estimated fairly reliably from simple electrical resistivity measurements.As the thermal conductivities of alloys depend strongly on their mechanical and thermal history (heat treatment) as well as on their chemical composition, the values tabulated below should be regarded as typical for the compositions listed. For many groups of alloys the thermal conductivity of a particular sample, near room temperature and above, can be estimated within about 6%from its more easily measured electrical conductivity using the relation λ = LσT + C. The optimum values for L and C for different alloy types are as follows:For more detailed information on the relationship between the thermal and electrical conductivities of alloys see: Powell (1965), Hust and Clark (1971).Thermal conductivities of alloys at ambient and elevated temperaturesNimonic 105 4.5 0.14 14.5 0.2 1 — 1 bal 1.0 ——20 Co, 5 Mo, 2 Ti — 11.6 14.7 17.4 21.2 27.6Carbon steels0.08 C, 0.3 Mn —0.08 0.045 —bal — 0.31 0.07 0.08 ———59 58 49 40 32 28 0.23 C, 0.6 Mn —0.23 —0.13 ,, — 0.64 0.07 0.11 ———52 51 46 39 32 27 0.42 C, 0.6 Mn —0.42 —0.12 ,, — 0.64 0.06 0.11 ———52 51 46 38 30 270.8 C, 0.2 Mn —0.84 —0.02 ,, — 0.24 — 0.13 ———51 49 42 36 31 271.2 C, 0.35 Mn — 1.22 0.11 0.08 ,, — 0.35 0.13 0.16 ———45 45 40 35 28 26 0.2 C, 1.5 Mn —0.23 0.06 0.10 ,, — 1.51 0.04 0.12 ———46 46 43 37 31 27Low alloy steels0.3 C, 1 Cr —0.32 1.09 0.07 bal —0.7 0.07 0.20 ———49 46 42 36 29 28 0.4 C, 1 Cr, 0.3 Ni —0.35 0.88 0.12 ,, —0.6 0.26 0.21 ———43 43 41 36 31 28 0.2 C, 0.6 Ni, 0.5—0.20 ——,, — 1.35 0.6 0.25 ——0.5 Mo 37 38 37 34 29 —Mo0.3 C, 0.2 Cr, 3.5—0.33 0.17 0.08 ,, — 0.55 3.47 0.18 ———36 38 38 34 28 28 Ni0.3 C, 1 Cr, 3.4 Ni —0.33 0.80 0.05 ,, — 0.53 3.38 0.17 ———34 36 37 35 29 28 0.4 C, 1 Cr, 3.6 Ni —0.4 0.8 —,, — 0.66 3.6 0.2 ———33 36 37.5 35 28 —0.3 C, ! Cr, 3.5 Ni —0.34 0.78 0.05 ,, — 0.55 3.53 0.27 ———33 34 36 34 28 28 0.5 C, 1 Mn, 2 Si —0.49 0.04 0.09 ,, — 0.9 0.16 2.0 ———25 28 31 31 28 26 High alloy steels1.2 C, 13 Mn — 1.22 —0.03 bal —13.0 0.07 0.22 ———13 15 18 21 23 26 0.3 C, 28 Ni —0.28 —0.03 ,, —0.9 28.4 0.15 ———13 15 18 21 23 28 4 Cr, 18 W, 1 V —0.72 4.26 0.06 ,, —0.25 0.07 0.30 18.5 — 1 V 24 26 28 28 27 28 Kovar —0.02 ——54 —0.47 29 ———17 Co 14.1 14.7 15.6 17.5 19.3 —Stainless steels304, 321, 347 —0.05 17.5 —bal —<2 9 <1 ———14.5 16.5 20 22.5 25.5 29.5 316 —0.05 17 —,, —<2 12 <1 —— 2.5 Mo 13.5 15 18.5 21.5 24 28.5 310 —0.1 24 —,, —<2 20 <1 ———12 13.5 17.5 20.5 23 —16 Cr, 20 Ni —0.01 16 —,, — 1.2 20 0.3 ———13.6 15.7 18.9 21.5 23.8 26.8Era-ATV —0.5 15 —,, — 1.2 27 1.3 2.8 ——11 12.5 15.5 —21.5 —403, 405, 409 —0.1 12 —,, —<2 —<1 ————25 26 27 ——430, 434 —0.05 17 —,, —<2 —<1 —— 1 Mo —22.2 22.9 23.7 24.4 —410, 420 —0.3 13 0.1 ,, —0.5 0.5 0.4 —————23.6 24.6 26.3 28Miscellaneous alloysPlatinum 90%, iridium 10% . . . . . . . . . . . . . . . . . . . . 31 —————Platinum 90%, rhodium 10% . . . . . . . . . . . . . . . . . . . . 38 —————Platinum 60%, rhodium 40% . . . . . . . . . . . . . . . . . . . . 46 51 58 69 ——Titanium 92.5%, aluminium 5%, tin 2.5% . . . . . . . . . . . . . . . . 7 8.3 10.5 ———Titanium 96%, aluminium 2%, manganese 2% . . . . . . . . . . . . . . . 9.3 10.5 10.7 ———Zirconium 93.1%, tin 6.7%, carbon 0.1% . . . . . . . . . . . . . . . . — 8.7 12 ———Zirconium 97.5%, tin 2.3%, carbon 0.1% . . . . . . . . . . . . . . . . —11.3 13 ———Thermal conductivities of alloys used in low temperature applicationsAlloyλ/(W m−1 K−1)Composition/weight percent Temperature/KAl C Cr Cu Fe Mg Mn Ni Si Sn Zn Other 273.2 173 100 50 20 4Aluminium alloys†Aluminium 99.99 ———————————228 —295 870 4100 1075 (1 C) 1100-0 bal —— 1 —0.05 0.05 — 1.0 —0.05 —205 —228 315 225 45 (N3) 3003 F ,, —— 0.12 —— 1.2 —————170 158 143 117 58 11 2219 T81 ,, —— 6.3 —0.02 0.3 — 0.20 — 0.1 —118 — 68 46 26 —(N8) 5083 0 ,, —0.15 0.1 — 4.5 0.7 —0.4 —0.25 —110 92 66 39 17 3.3 7039 T61 ,, —0.2 0.1 — 2.8 0.25 —0.2 — 4 —150 — 96 64 30 14.7Copper alloysCopper ———99.96 ————————400 —480 1230 3700 1450 ETP Cu ———99.95 ————————395 —445 880 1320 325 OFHC Cu ———99.95 ————————400 —460 750 900 200 Brass ———70 ——————30 —106 92 70 45 21 4 Brass ———65 ——————35 —113 — 59 ———Cupro-nickel ———90 ———10 ——————— 31 14 1 German Silver ———62 ———15 ——22 —23 20 ————Copper Beryllium ———98 ——————— 2 Be ——— 24 10 2Nickel alloysNickel ——————— 99.99 ————94 115 154 320 865 138 Inconel X 0.9 0.04 15 — 7 —0.7 73 0.3 —— 2.5 Ti 11.4 10 8.7 ———K. Monel 3 0.15 —30 1 —0.6 65 0.15 ———17 14 12 ———Hastelloy X —0.15 22 —24 ——45 ———9 Mo 9.9 8 6.5 5 3 0.5 Inconel 718 0.4 0.04 18.6 — 18.5 —————— 1 Ti, 5 Nb, 3 Mo 10 8.7 7 4.8 2.6 0.4SteelsArmco iron —0.02 —— 99.8 — 0.03 —————76 83.6 95 109 65 132.5% Ni —0.1 ——bal —0.8 2.5 0.2 ———38 33 ————3.5% Ni —0.1 ——,, —0.8 3.5 0.2 ———34 29 21 ———5% Ni —0.1 ——,, —0.8 5 0.2 ———31 26 19 10.5 ——9% Ni —0.1 ——,, —0.8 9 0.2 ———28 23 16 8.5 3.5 1 Invar 36% Ni —0.07 ——,, —0.4 36 0.2 ———13.5 11 7.7 4.3 1.6 —Stainless steels304/306/321/347 —0.05 18 —bal — 2 8–12 1 ———14.5 11.5 9 5.5 2 0.3 310 —0.2 25 —,, — 2 20 1.5 ———11 8.3 6.9 4.3 1.7 —16 Cr, 20 Ni —0.01 16.2 —,, — 1.2 20.2 0.28 ———13.6 11.5 9.3 6.0 2.4 0.4 15 Cr, 26 Ni —0.05 15 —,, — 1.4 26 0.4 —— 1.3 Mo, 0.3 V 11.2 —7.6 5.0 2.2 1.0Titanium alloysTitanium ———————————99.9 Ti 22 26 31 40 28 14Ti 5 Al 2.5 Sn 5 0.1 ——0.4 —0.2 —— 2.5 —— 7.8 6.1 4.8 3.6 2.0 —Ti 6 Al4 V 6 0.05 ————————— 4 V 7.0 5.4 4.0 2.5 1.3 —Ti 13 V 11 Cr 3 Al 3 0.08 11 —0.3 ——————13 V 7.4 5.0 3.4 1.9 0.9 —†American Aluminium Association Designation (BS Equivalent in brackets).Thermal conductivities of elements which are semi-conductors or insulatorsλ/(W m−1 K−1)Entries in italics relate to the liquid phase.Thermal conductivities of refractory materials: Dense, polycrystalline, single-phase compoundsλ/(W m−1 K−1)Oxides:Alumina Al2O3†38 35 11 7 6 Aluminosilicate Al6Si2O13— 6 4.5 4 —Beryllia BeO 300 220 70 18 14 Calcia CaO —15 8.7 7.8 —Magnesia MgO†40 35 16 7 6.5 Spinel MgAl2O416 15 9 6 —Silica SiO2 (vitreous)† 1.6 1.7 2.1 5.0 —Thoria ThO214 12 6 2 2 Titania TiO2— 9.2 4.5 3.3 —Urania U2O 12 8 4.5 3.2 —Zirconia ZrO2 (stabilised)† 1.8 1.8 2.0 2.2 2.4 Zircon ZrSiO4 8 5.8 4.8 4.2 —Quartz SiO2 (single crystal)along c-axis 11 8.3 5 ——normal to c-axis 6.5 5 3.6 ——Carbides:Boron carbide B4C 30 25 21 71 15 Silicon carbide SiC 110 90 65 45 40 Titanium carbide TiC 30 32 36 40 45 Tungsten carbide WC 40 ——45 50 Zirconium carbide ZrC ——31 35 —Nitrides:Aluminium nitride AlN 36 33 23 ——Silicon nitride Si3N4 (1% MgO) 30 28 21 14.5 13 Titanium nitride TiN —25 27 ——Borides:Titanium diboride TiB2—70 64 ——Zirconium diboride ZrB2—73 67 ——Silicon (AXM–5Q) Si 150 110 45 26 —† Values at high temperatures are influenced by radiation transmission, especially in single crystal form.Thermal conductivities of oxide and silicate ceramics: Commercial products.Composition and density may vary, values should be taken as typical of type.λ/(W m−1 K−1)† Values at high temperatures are influenced by radiation transmission.For further information on refractory materials consult Morrell (1985).For further information on the thermal conductivities of solid materials generally at high temperatures see, for example, Powell (1954).Thermal conductivities of miscellaneous solidsThe values below are for normal temperature, except where stated (K) and should be regarded as average values for the type of material specified. Values for the commoner polymers will be found in section 3.11.1.lightweight aggregate 0.2–0.6 dense 0.6–1.8 Cotton wool 0.03Cork, baked slab 0.038–0.046 ,, granular 0.04Diatomaceous powder 0.07Ebonite, solid 0.17,, cellular 0.03Felt 0.04Fibreboard, insulating 0.055,, hardboard 0.125Glass, borosilicate crown 1.1,, double extra dense flint 0.55Glass, light flint 0.85,, Pyrex 1.1Glass, mineral, ceramic fibre:**wool blanket 0.035–0.07 rigid board 0.030–0.036 Ice (268) 2.3,, (173) 3.9 Kapok ~ 0.035 Mica 0.6–0.7 Paper ~ 0.06 Paraffin wax 0.25 Plasterboard (gypsum) ~ 0.16 Plasticine 0.65–0.8Plastics, solid (see sec 3.11.1)Plastics, cellular: (varies withdensity) 0.031–0.037 phenolic foam board 0.031–0.038 polystyrene, expanded board 0.035–0.055 polystyrene, expanded beadspolyurethane, gas-filled board 0.017–0.020 (fresh)polyurethane, gas-filled 0.027board (aged)polyvinyl chloride, rigid foamboard 0.035–0.041 urea formaldehyde foam 0.030–0.032 Plywood 0.125Pyrophyllite, normal toplane ~ 2.0Rubber, cellular* ~ 0.045 ,, natural ~ 0.15 ,, silicone 0.25–0.4 Sand, silver 0.3–0.4 Silica aerogel powder* 0.024 Soil, clay ~ 1.1Timber, ordinary 0.14–0.17 ,, balsa 0.055Vermiculite granules ~ 0.065 Wool ~ 0.05* Values depend on density, generally increasing with increasing density.** Thermal conductivity decreases to a minimum before increasing with increasing density.Thermal conductivites of liquidsValues below are for the thermodynamic temperature (K) shown in brackets. Linear relationships mostly hold for range covered. Liquid metal values are given in the table Thermal conductivities of metallic elements.Thermal conductivities of some liquids and their vapours (λ/(W m−1 K−1))In the table below the thermal conductivities of liquids at their equilibrium saturation pressure are compared with the values for their dilute vapours at the same temperatures.He H2 A C6H6H2O KNO3 Temperature/K 4 20 90 298 373 683Vapour 1.25 × 10−40.0145 0.0057 0.0070 0.0217 —Liquid 0.0275 0.1178 0.1198 0.1463 0.6819 0.425Thermal conductivities of gasesThe thermal conductivity of a gas is independent of pressure at normal pressures. It increases at high pressures and decreases at low pressures, e.g. for air below about 1 mm Hg. Values are given for a pressure of 1 atm.λ/(10−2 W m−1K−1)ReferencesJ. G. Hust and A. F. Clark (1971) The Lorentz ratio as a tool for predicting the thermal conductivity of metals and alloys, Mat. Research and Standards, 11(8), 22–24. R. Morrell (1985) Handbook of Properties of Technical and Engineering Ceramics, Part 1, HMSO, London.R. W. Powell (1954) Thermal conductivities of solid materials at high temperatures, Research, 7, 492–501.R. W. Powell (1965) Correlation of metallic thermal and electrical conductivities for both solid and liquid phases, Int. J. Heat and Mass Transfer, 8, 1033–1045. Y. S. Touloukian, R. W. Powell, C. Y. Ho and P. G. Klemens (1970a) Thermophysical Properties of Matter Volume 1: Thermal Conductivity: Metallic Elements and Alloys, IFI/Plenum Data Corp., New York, Washington.Y. S. Touloukian, R. W. Powell, C. Y. Ho and P. G. Klemens (1970b) Thermophysical Properties of Matter Volume 2: Thermal Conductivity: Nonmetallic Solids,IFI/Plenum Data Corp., New York, Washington.Y. S. Touloukian, P. E. Liley and S. C. Saxena (1970c) Thermophysical Properties of Matter Volume 3: Thermal Conductivity: Nonmetallic Liquids and Gases,IFI/Plenum Data Corp., New York, Washington.。