RU1770431C - Protective alloy on magnesium-base - Google Patents

Description

1

(21) 4848433/02 (22) 05.07.80 (46) 10.23.92. Bull. Number 39

(71) State Research and Design Institute for the Development of Offshore Oil and Gas Fields Tipromorneftegaz and Bereznmkovsky Titanium-Oil Plant

(72) B.M., Akhmedov, A.Z. Kashkarov, A.U. Khanlarova, S.A. Mehmachdarov, B.C. Sakov, V.V. D tlov, A.A. Troshkina, A.D. Stolbova and A.S. Bushmakin

(56) Copyright certificate of the USSR No. 1163649, class C 22 C 23/02, 1983.

(54) MAGNETIC-BASED PROTECTOR ALLOY

(57) The alloy can be used to protect metal structures and structures from corrosion in sea water. The alloy contains, wt.%: Zinc 2.0-2.9, manganese 0.05-0.5, aluminum 5.0-7.0, titanium 0.0001-0.0009, neodymium 0.005-0.018. magnesium is the rest. The alloy has a specific current capacity of 1465-t541 A.h / kg. corrosion rate without current load 0.0270-0.0315 g / m2.h. 4 tab. A ml.

The invention relates to the metallurgy of magnesium-based tread alloys used to protect metal structures and structures from corrosion in sea water.

Known magnesium based alloy containing, wt.%: Aluminum Zinc

Manganese

Rare Earth Metals Magnesium

no more

5.0 ... 10.0 2.0 ... 4.0 0.15 ... 0.5 0.05 ... 2.0 Else Impurities,

Chlorides 0.005

Iron 0.003

Copper0.004

Nickel 0.001

However, the alloy has insufficiently high electromechanical properties. The efficiency at a current density of (1 ... 10) A / m2 is (58.0 ... 64.5)%.

The operating (average) coefficient in the short-circuited system is 63.5%, and in the non-disconnected one it is 60%.

Closest to the proposed is a magnesium-based alloy for treads, containing, wt.%:

Zinc0.5 ... 4.0

Manganese 0.001.,. 0.5

Aluminum 4.0 ... 10.0

Titanium 0.0001 ... 0.009

one or two metals from the group including:

Lead 0.05 ... 0.6

Neodymium 0.02 ... 0.2

Magnesium Else

However, said alloy has lower specific current capacitance values. efficiency and increased corrosion rate (self-dissolving) without current load

The purpose of the invention is to improve the electrochemical characteristics and reduce the corrosion rate without current load.

with C

vi

VI

ABOUT

b

with

/ ilch of achievement and ;; and the alloying content of these elements in the alloy is set to i lg-d / updich ratios. wt.%:

Zinc2, - -. 1, y

Manganese 0.05 .., 0.5

Aluminum, 0, .. 7.0

Titanium0.0001.0.0009

Neodymium .005 ,,. 0.018

Impurities, no more

Iron 0.01

Copper 0.08

Nickel0.001

Silicon 0.09

Magnesium Potalnoe

The chemical composition and esomg.-gga and le / - ;, of the alloys listed are 5 tables. 1 and table 2.

I, T H OnprPfV YANMA PR DIGGER. f) L if ovw i - | . gg, - (, m v. ski composition KOicpti is given in gauge t,

Each mixture was melted separately in the Alzk furnace of the experimental workshop of the birch titanium-magnesium plant (BTMK, Mr. Berezniki, Perm Region) into a crucible.

Electrochemical properties are determined on a galvanostatic installation. Every day, for 20 days, the electrode potentials of the samples were measured, both loaded under constant electric current and unloaded (control), immersed in cells with the Caspian sea; - soft water,

Tests of e-alloys were decided in an itoebel of density - one polarizing tskg (20 ... 140).

Fig. I shows the dependences of the specific current capacitance (curves 1, 2, 3) and the efficiency (curves 4, 5, 6) of these alloys on the density of the caked current.

Curves 1 and 4 in weight. %: zinc - 2.0; Manganese - 0.05: Aluminum - 5.0; titanium - 0.0001; neodymium - 0.005. Curves 2 and B in May. %: zinc - 2.5; manganese -0.16: aluminum mmium - 6.0; IT-0.0005; neodymium-0.009. Curves 3 and 6 in CPC.%: Zinc - 2.9; manganese - 0.5; aluminum - 7.0; titanium - 0.0009; neodymium - 0.018.

In FIG. Figures 2, 3 and A show the changes in time of the electrotune gute: shialch of this h, melt with Caspian sea water with the above-mentioned acodma :; dense 1 lx of polarizing current. The alloys of FIG. 2 .4 differ from each other in the content fa wt.%) Of the composition (see table 1): fig. 2 - composition 1. FIG. 3 - composition 2 and FIG. 4 - - composition 3, respectively.

As can be seen from FIG. 1 ... 4, the electrochemical properties of the alloy is the coefficient of PSIRZ use at the density of the gc

(20 .., 140} mA / dm and theoretical specific current capacitance equal to 2220 A h / kg for magnesium - (66 ... 89 4)%, working potential - 1220 mV with respect to the hydrogen electrode is comparable to NIR. Corrosion rate (self-dissolving) ) without, the current load (0.0270.,. 0.0315) r / m.h. Moreover, the greatest positive effect is obtained for the alloy composition 7 (see table. 2), departing from these limits as

upward and downward, leads to a relative decrease in this esM a.

v, also the transcendental values of the claimed alloy are also indicated. In the table. 3 shows them

chemical compositions, and in table. 4 - electrochemical properties.

As can be seen from the table. 3 m table 4, the departure of the limits to the side of reduction leads to a decrease in electrochemical properties

alloy, and in the direction of increase to a significant increase.

The base object for the object we have proposed is a tread cast from MP-2 alloy according to TU 48-10-23-0.

Using the proposed alloy

when casting magnesium protectors for corrosion protection, mainly offshore structures and structures in the underwater zone are relatively known for

a year can save on one ton (200 ... 250) rubles.

Taking into account the annual demand for such protectors of Kaspmorneftegas software on average 1000 tons, the total annual savings from them

use may amount to (200 ... 250) thousand rubles.

The use of a new magnesium alloy in the tread protection against corrosion, especially the underwater parts of offshore oil and gas field steel structures, will improve the electrochemical properties of mx, and thereby increase the life of the treads, which ultimately reduces the cost of the tread protection system.

Formula a invented and

A magnesium-based tread alloy containing zinc, manganese, aluminum, titanium and neodymium, characterized in that, in order to improve the electrochemical characteristics and reduce the corrosion rate without current load, it contains components in the following ratio, wt.%: Zinc 2.0 -2.9

Manganese 0.05-0.5

Aluminum 5-7

Titanium 0.0001-0.0009

Neodymium 0.005-0.018

Magnesium Else

The chemical composition of the alloy

Alloy

Composition number

Magnesium

Proposed

1 2 3

Rest

Electrochemical properties of alloys

Electrochemical parameters

1

Specific current capacity, A.

h / kg

Coefficient of use. % Operating potential, -mV over the hydrogen reference electrode Corrosion rate (self-dissolving) without current load, r / m2. h

The chemical composition of transcendental alloys

 ... - - - --in - - - - - - -m ... -

Alloy No. Content of components, wtD

magnesium zinc manganese aluminum titanium neodymium

. "" .Vvvvvivivvvvv chvv 11 ™ in - ™ - ™ - ™ in ".v.-

1 else 1.6 0.04 h, 0 0.00008 0.00 h 3.3 0, b5 8.1 0.00130 0.020

Table Electrochemical properties of transcendental alloys

..- "---" - --------------- Electrochemical vapor- Alloy, 1g

meters

Specific current capacity, A.h / kg1 2 1525

Coefficient of use, 6h 68.7

Working potential, -mV over the hydrogen electrode of comparison 1205 1220

Corrosion rate (self-i-boiling) without current load, g / m.chO. ° 580 0,0315

Table 1

de

) burning components, wt.%

Manganese Aluminum Titanium Neodymium

0.05 0.16 0.50

5.0 6.0 7.0

0.0001 0.0005 0.0009

0.005 0.009 0.018

 table 2

S l

proposed

known by author St. 1163649

1541 69.4

1220 .0270

1534 69.1

1219 0.0290

1405 63.4

1195

T a

0.04J2

b l c a T

400

About 20 40

4200

02 4 at 8 10 2 And 6 8 20T, day

42.2

0 Z 4 S 8 10 f2 14 & 8.

ute. /