Industrial Pure Titanium
Titanium casting forgings are mainly used in chemical, petroleum, light industry, textile, marine, electric power, metallurgy, machinery and other departments. The main products are pump impeller, pump shell, valve body, turbine, fan impeller, marine propeller impeller, compressor housing, pipe fittings, centrifuge drum, hovercraft hydraulic jet propeller impeller, etc.
|
Old standard brand |
Major component impurity elements, not greater than |
Density |
Applicable temperature |
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|
Ti |
Fe |
C |
N |
H |
O |
The remaining individual impurities |
Total remaining impurities |
|||
|
TA0 |
Allowance |
0.15 |
0.10 |
0.03 |
0.015 |
0.15 |
0.1 |
0.4 |
4.506g/cm3 |
≤425℃ |
|
TA1 |
Allowance |
0.25 |
0.10 |
0.03 |
0.015 |
0.20 |
0.1 |
0.4 |
4.506g/cm3 |
≤425℃ |
|
TA2 |
Allowance |
0.30 |
0.10 |
0.05 |
0.015 |
0.25 |
0.1 |
0.4 |
4.506g/cm3 |
≤425℃ |
|
TA3 |
Allowance |
0.40 |
0.10 |
0.05 |
0.015 |
0.30 |
0.1 |
0.4 |
4.506g/cm3 |
≤425℃ |
|
Old standard brand |
Mechanical properties of old standard room temperature, not less than |
Mechanical Properties of New Standard Titanium Foundry |
Bar brand |
Room temperature mechanical properties, not less than |
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|
Rm/MPa tensile strength |
Rp0.2/MPa of specified proportional extension strength |
A/% elongation after break |
Z/% of section shrinkage |
New Standard Licence |
Code |
ob N/m㎡ tensile strength |
A specified residual elongation stress or0.2N/m㎡ not less than |
Elongation δ5%, not less than |
Hardness HB not greater than |
Rm/MPa tensile strength |
Rp0.2/MPa of non-proportional extension |
A/% elongation after break |
Z/% of section shrinkage |
Remarks |
||
|
TA0 |
280 |
170 |
24 |
30 |
||||||||||||
|
TA1 |
370 |
250 |
20 |
30 |
ZTi1 |
ZTA1 |
345 |
275 |
20 |
210 |
TA1 |
240 |
140 |
24 |
30 |
|
|
TA2 |
440 |
320 |
18 |
30 |
ZTi2 |
ZTA2 |
440 |
370 |
13 |
235 |
TA2 |
400 |
275 |
20 |
30 |
|
|
TA3 |
540 |
410 |
15 |
25 |
ZTi3 |
ZTA3 |
540 |
470 |
12 |
245 |
TA3 |
500 |
380 |
18 |
30 |
|
|
ª of supply status of old brand |
Heat Treatment of New Standard Titanium Foundry |
Heat treatment of bar grade |
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|
Alloy grade |
Temperature ,℃ |
Heat preservation time (min) |
Cooling mode |
Supply status |
Bar brand |
Heating temperature, holding time, cooling mode |
|
|
state of hot working (R), state of cold working (Y), state of annealing (M) |
ZTi1 |
500∽600 |
30∽60 |
Cold furnace |
cast (C), stress-free annealing (M), hot isostatic pressing (HIP) |
TA1 |
600℃∽700,1 h∽3 h, air cooling |
|
state of hot working (R), state of cold working (Y), state of annealing (M) |
ZTi2 |
500∽600 |
30∽60 |
Cold furnace |
cast (C), stress-free annealing (M), hot isostatic pressing (HIP) |
TA2 |
600℃∽700℃,1 h℃∽3 air cooling |
|
state of hot working (R), state of cold working (Y), state of annealing (M) |
ZTi3 |
500∽600 |
30∽60 |
Cold furnace |
cast (C), stress-free annealing (M), hot isostatic pressing (HIP) |
TA3 |
600℃∽700℃,1 h℃∽3 air cooling |
Total corrosion
titanium has excellent corrosion resistance in oxidizing and neutral media. at this time, the oxide film on the titanium surface can exist stably, and can recover quickly after being destroyed for some reasons. In strongly reducing acids, titanium oxide films are easily dissolved and therefore not corrosion resistant. in some dilute reducing acids with low temperature, titanium also has a certain corrosion resistance, especially when the reducing acid contains oxidizing metal ions, oxygen and other oxidants, titanium also has better corrosion resistance.
the corrosion resistance of titanium in the main medium is described below, respectively.
1. nitric acid
titanium has excellent corrosion resistance in various concentrations of nitric acid below boiling point.
2. sulfuric acid
titanium is not corrosion resistant in 10%~98% concentration of sulfuric acid and can only be used in 5% dissolved oxygen sulfuric acid at room temperature. At 100℃, titanium can only retain pure titanium in 0.2 sulfuric acid.
3. sulfuric acid
titanium has moderate corrosion resistance in hydrochloric acid. Generally, industrial pure titanium can be used in hydrochloric acid at room temperature ,7.5%;60℃,3%;100℃,0.5%. There have also been reports of lower concentrations that could be used.
4. phosphoric acid
Titanium can be used in 35℃,30%;60℃,10%;100℃, less than 3% phosphoric acid. the corrosion resistance of titanium in phosphoric acid can be improved if Fe+3, CuFe+2, AgFe+1,2 and nitric acid are contained in the medium.
5. other inorganic acids
titanium is not corrosion resistant in hydrofluoric acid and can not be used in acid fluoride solutions. Titanium is resistant to corrosion in boric acid, chromic acid; it can be used in some hydroiodic acid, hydrobromic acid; it is generally not used in fluorobic acid, fluorosilicic acid. titanium can be used for mixed acid of 60℃,10% sulfuric acid and 90% nitric acid; mixed acid of boiling 1% hydrochloric acid and 5% nitric acid as well as in room temperature Wang Shui.
6. bases and salts
titanium is resistant to most lye. titanium is completely resistant to corrosion in various concentrations of barium hydroxide, calcium hydroxide, magnesium hydroxide, sodium hydroxide and potassium hydroxide solutions at room temperature and can not be used in boiling sodium hydroxide, potassium hydroxide solutions. When the alkali solution contains free chlorine, titanium can resist corrosion. ammonia in the base will aggravate the corrosion of titanium.
7. water
titanium has excellent corrosion resistance in tap water and river water even if the temperature is up to 300℃. At the
120℃ High corrosion resistance in seawater; point corrosion and crevice corrosion may occur if the temperature is increased.
8. organic matter
titanium has excellent corrosion resistance to all organic acids except ant acid, oxalic acid and concentrated citric acid.
9. chlorine, chlorides and other halogens
Titanium can react violently in dry chlorine gas to form titanium tetrachloride, and it is in danger of ignition. Because titanium tetrachloride can react with water to form titanium hydroxide, titanium has good corrosion resistance in wet chlorine. The water content needed for the purification of titanium in chlorine gas is related to the temperature, flow rate, pressure and damage of titanium surface film. generally, the minimum water content required to maintain titanium purification is 0.01%~0.05%. usually in order to ensure safe production, when chlorine gas is in contact with titanium equipment, the water content in chlorine gas is actually controlled at about 0.3%, even sometimes up to 1.5%.
10. Urea ammonium formate solution
The corrosion rate of titanium in high temperature and high pressure urea ammonium formate solution is generally 0.01 mm/a, which is one quantity pole lower than that of 00 Cr 17Ni 14Mo 2 stainless steel. the maximum temperature allowed for titanium to maintain corrosion resistance can reach 205~210℃, while stainless steel can only withstand corrosion below 190~195.
11. Gas
titanium can be oxidized. dense oxide film is formed below 300℃, and oxide film formed below 700℃ can improve corrosion resistance. When the temperature is higher, the oxide film becomes brittle and easily exfoliated into oxide skin. as structural materials, titanium can be used below 425℃ in air; as non-structural materials, it can be used below 535℃.
Titanium has excellent corrosion resistance in sulfur dioxide, hydrogen sulfide, ammonia gas and oceanic atmosphere.
At more than 300℃, hydrogen can obviously enter titanium, in addition to the physical infiltration of hydrogen in titanium to cause hydrogen embrittlement of titanium, hydrogen can also be combined with titanium to form hydrogen embrittlement of hydride type. increasing the hydrogen partial pressure will aggravate the hydrogen embrittlement of titanium. When the water content in hydrogen exceeds 2%, it can effectively prevent hydrogen infiltration. anodized surface treatment can improve the hydrogen resistance of titanium.
local corrosion
Compared with stainless steel, nickel-based alloy, copper alloy and aluminum alloy, industrial pure titanium has high resistance to local corrosion, excellent resistance to point corrosion, and is insensitive to intergranular corrosion, stress corrosion, corrosion fatigue and so on, which can only occur in very few media. titanium, like other purified metals, is more prone to crevice corrosion and can also produce selective corrosion and contact corrosion in very few cases. As long as we pay attention to the use conditions of titanium and take appropriate measures, the local corrosion of titanium can be avoided mostly.
Corrosion resistant titanium alloy
In the case that industrial pure titanium can not meet the corrosion requirements, corrosion resistant titanium alloy can be used.