摘要:
A method manufacturing an aluminum alloy sheet comprising preparing an aluminum alloy ingot essentially consisting of 1.5 to 3.5% by weight of Mg, 0.3 to 1.0% by weight of Cu, 0.05 to 0.6% by weight of Si, and a balance of Al, in which the ratio of Mg/Cu is in the range of 2 to 7, homogenizing the ingot in one step or in multiple steps, performed at a temperature within a range of 400 to 580.degree. C., preparing an alloy sheet having a desired sheet thickness by subjecting the ingot to a hot rolling and a cold rolling, subjecting the alloy sheet to heat treatment including heating the sheet up to a range of 500.degree. to 580.degree. C. at a heating rate of 3.degree. C./sec. or more, keeping it for 0 to 60 seconds at the temperature reached, and cooling it to 100.degree. C. or less at a looking rate of 2.degree. C./sec. or more, and keeping the alloy sheet at a temperature within a range of 180.degree. to 300.degree. C. for 3 to 60 seconds. Thus, a natural aging-retardated aluminum alloy sheet is obtained.
摘要:
Disclosed is an aluminum alloy sheet having a chemical composition of an Si-containing Al--Mg--CU alloy. The aluminum alloy sheet exhibits a streak-shaped modulated structure at a diffraction grating points of an Al--Cu--Mg--system compound in the electron beam diffraction grating image. The above mentioned streak can be generated efficiently when the alloy essentially consists of 1.5 to 3.5% by weight of Mg, 0.3 to 1.0% by weight of Cu, 0.05 to 0.6% by weight of Si, and the balance of Al and inevitable impurities, and the ratio of Mg/Cu is in the range of 2 to 7. The alloy contains 0.01-0.50% of at least one element selected from the group consisting of Sn, Cd, and In.
摘要:
Disclosed is a method manufacturing an aluminum alloy sheet comprising preparing an aluminum alloy ingot essentially consisting of 1.5 to 3.5% by weight of Mg, 0.3% to 1.0% by weight of Cu, 0.05 to 0.35% by weight of Si, 0.03 to 0.5% by weight of Fe, 0.005 to 0.15% by weight of Ti, 0.0002 to 0.05% by weight of B and a balance of Al, in which the ratio of Mg/Cu is in the range of 2 to 7, homogenizing the ingot in one step or in multiple steps, performed at a temperature within the range of 400.degree. to 580.degree. C., preparing an alloy sheet having a desired sheet thickness by subjecting the ingot to a hot rolling and a cold rolling, subjecting the alloy sheet to a heat treatment including heating the sheet up to a range of 500.degree. to 580.degree. C. at a heating rate of 3.degree. C./second or more, keeping it at the temperature reached for 0 to 60 seconds, and cooling at a cooling rate of 2.degree. C./second or more, subjecting the alloy sheet to a preliminary aging treatment performed at a temperature within the range of 45.degree. to 100.degree. C. for 2 to 48 hours after keeping at room temperature or immediately after the heat treatment, and subjecting the alloy sheet to a restoring treatment performed at a temperature within the range of 180.degree. to 300.degree. C. for 3 to 60 seconds. Thus, a natural aging-retardated aluminum alloy sheet exhibiting excellent formability and excellent bake hardenability is obtained.
摘要:
A carburizing steel has a composition containing, in mass %, C: 0.1-0.35%; Si: 0.01-0.22%; Mn: 0.3-1.5%; Cr: 1.35-3.0%; P: 0.018% or less; S: 0.02% or less; Al: 0.015-0.05%; N: 0.008-0.015%; and O: 0.0015% or less, each being contained in an amount within a range satisfying formulas (1), (2) and (3) below, and the balance of the composition being Fe and incidental impurities, and the carburizing steel having microstructures before spheroidizing annealing such that a total microstructure proportion of ferrite and pearlite is 85% or more and an average ferrite grain size is 25 μm or less. 3.1≧{([% Si]/2)+[% Mn]+[% Cr]}≧2.2 (1) [% C]−([% Si]/2)+([% Mn]/5)+2[% Cr]≧3.0 (2) 2.5≧[% Al]/[% N]≧1.7 (3) [% M] represents content (in mass %) of element M.
摘要:
An internal high hardness type pearlitic rail that has a composition containing 0.73% to 0.85% by mass C, 0.5% to 0.75% by mass Si, 0.3% to 1.0% by mass Mn, 0.035% by mass or less P, 0.0005% to 0.012% by mass S, 0.2% to 1.3% by mass Cr, and the balance being Fe and incidental impurities, in which the value of [% Mn]/[% Cr] is greater than or equal to 0.3 and less than 1.0, where [% Mn] represents the Mn content, and [% Cr] represents the Cr content, and in which the internal hardness of a rail head that is defined by the Vickers hardness of a portion located from a surface layer of the rail head to a depth of at least 25 mm is greater than or equal to 380 Hv and less than 480 Hv.
摘要:
An internal high hardness type pearlitic rail that has a composition containing 0.73% to 0.85% by mass C, 0.5% to 0.75% by mass Si, 0.3% to 1.0% by mass Mn, 0.035% by mass or less P, 0.0005% to 0.012% by mass S, 0.2% to 1.3% by mass Cr, and the balance being Fe and incidental impurities, in which the value of [% Mn]/[% Cr] is greater than or equal to 0.3 and less than 1.0, where [% Mn] represents the Mn content, and [% Cr] represents the Cr content, and in which the internal hardness of a rail head that is defined by the Vickers hardness of a portion located from a surface layer of the rail head to a depth of at least 25 mm is greater than or equal to 380 Hv and less than 480 Hv.
摘要:
A heat-resistant TiAl alloy having excellent room-temperature fracture toughness, high-temperature oxidation resistance and high-temperature strength is disclosed. Said alloy consists essentially of from 29 to 35 wt. % aluminum, from 0.5 to 20 wt. % nobium, and at least one element selected from the group consisting of from 0.1 to 1.8 wt. % silicon, and from 0.3 to 5.5 wt. % zirconium, the balance being titanium and incidental impurities. Preferably impurities are limited to 0.6 wt.-% oxygen, 0.1 wt.-% nitrogen and 0.5 wt.-% hydrogen.
摘要:
A pearlite rail contains, by % by mass, 0.70 to 1.0% C, 0.1 to 1.5% Si, 0.01 to 1.5% Mn, 0.001 to 0.035% P, 0.0005 to 0.030% S, and 0.1 to 2.0% Cr by mass with the balance being Fe and inevitable impurities, wherein a γ+θ temperature range is 100° C. or lower.