T.O. 1-1A-9
f.
AZ81A - Used in sand or permanent mold castings for good strength, excellent ductility, pressure tightness and
toughness. Readily castable with low micro-shrinkage tendency. Solution heat treat 775°F for 18 hours, cool in air or by
fan. Stabilizing treatment 500°F, 4 hours and air cool. To prevent germination (grain growth) an alternate heat treat of
775 F for 6 hours, 2 hours at 665°F and 10 hours at 775°F may be used. Weld with helium or argon-arc method using
AZ92A rod or base metal rod. Preheat is not necessary in structural welding. Emergency repair with oxyacetylene
neutral flame, AZ92A rod and flux may be done. Stress relieve after welding.
g.
AZ91A, AZ91B AZ91A - Used for die castings generally.
h.
AZ91C - AZ91B is also die cast alloy but has higher impurity content. AZ91C is used for pressure tight sand and
permanent mold castings having high tensile and weld strength. Shortness temperatures are above 7500°F. Heat treat:
T-4 condition, 16 hours at 780 F, cool in air blast and then age at 400F for 4 hours; T-7 condition, 5 hours at 450F.
Foreign equivalents are Elektron AZ91 and British DTD136A. Good impact resistance in T-4 temper. T-6 has good yield
strength and ductility.
j.
AZ92A - Used in pressure tight sand and permanent mold castings. Has high tensile and yield strengths.
Solution heat treat 20 hours at 760F in an atmosphere of 0.5% SO2. Cool in strong air blast. Artificial aging is done at
420°F for 14 hours. Cool in air or oven. Stabilize for 4 hours at 500F, then cool in air. Equal to AX63A in salt water
corrosion resistance.
k.
EK30A - Used in sand casting for elevated temperature applications. Has good strength properties in
temperature range 300500F. Solution heat treat at 1060F maximum 16 hours then cool in air by fan. Age at 400F
then air cool. Weld by helium or argon arc method using EZ33A or base metal rod. May be preheated if desired. Stress
relieve after welding. Castings are pressure tight.
l.
EK41A - Used as pressure tight sand casting alloy. Good strength at300 500F. Solution heat treat at 1060F
maximum 16 hours then cool in air or with fan. Age at 400F 16 hours, air cool. Helium or argon arc weld using EZ33A
or base metal rod. May be preheated as desired. Stress relieve after welding.
m.
EZ33A - Used for pressure tight, good strength sand and permanent mold castings where temperatures may
reach 500F in use. Age at 420F for 5 hours. Weld with helium or argon gas arc method using EZ33A rod. Stress
relieve after welding. Foreign equivalent British ZRE1.
n.
HK31A - Used in sand castings for elevated temperature use up to 650°F and sheet and plate applications. Has
excellent weld and forming characteristics in sheet/plate form and retains good strength up to 650°F. Hot working
temperature is 800to 1050F. Anneal at 750F. Solution heat treat sand castings by loading into a 1050°F furnace and
holding for 2 hours, then fan or air cool. Age for 16 hours at 4000F. H23 sheet may be stress relieved after welding at
650F for 1 hour or 675F for 20minutes. Weld using helium or argon gas arc weld and EZ33A or HK31A rod. Stress
relieve sand castings. Sheet maybe resistance welded.
p.
HM21A - Used sheet, plate and forgings, usable at 650
F and above. Hot work at 850F 1100F Anneal at
850F. Heat treat forgings (T5) 450F for 16 hours. Weld with helium or argon gas arc method using HM31A rod when
service temperature will be above 600°F or EZ33A rod for lower temperatures. Resistance welding is also satisfactory.
q.
HM31A - Used in extruded bars, rods, shapes and tubing for elevated temperature service. Exposure to
temperatures through 600F for periods of 1000 hours caused practically no change in short time room and elevated
temperature properties. Superior modulus of elasticity particularly at elevated temperatures. Hot work at 700
F 1000F.
Weld by resistance method or helium argon gas arc methods. Use HM31A rod for temperature application in excess
600F or EZ33A rod where temperature will be below 600F . No stress relief after welding is necessary.
r.
HZ32A - Used for sand castings. It is of properties for medium and long range exposure at temperatures above
500°F and is pressure tight.
s.
KIQA - Casting alloy with comparatively low strength has excellent damping characteristics.
t.
MIA - Used for wrought products and provides for moderate mechanical properties with excellent weldability,
corrosion resistance and hot formability. Hot work at 560 100F. Anneal at 700F. Stress relieve annealed sheet at
5000F,in 15 minutes; hard rolled sheet at 400°F in 60 minutes; and extrusions at 500°F in 15 minutes. Shielded arc,
oxyacetylene gas and resistance welding are used for joining. Use MIA rod where applicable and a neutral flame and
magnesium flux for gas welds. Stress relief is not required, but maybe used. Foreign equivalents are British BS1352
(forgings) and German AM503.
u.
QE22A - Castings have high yield strength at elevated temperatures. Solution heat treat at 970
-990F 4 to 8
hours. Quench in 150F water bath.
v.
TA54A - Best hammer forging alloy.
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