DE1533539B2 - ADDITIONAL MATERIALS FOR COLD WELDING OF LAMELLAR OR GLOBULAR GRAY IRON - Google Patents

Description

0.05 until 0.20% Carbon, 0.15 until 0.80% Silicon, 0.4. until 1.0 7o Manganese, 5 until 11% Vanadium, 0.005 until 0.12% Boron, possibly 0.05 until 2.2% Niobium or Niobium / tantalum, possibly 0.3 until 1.5 7o Nickel, less than 0.025% Phosphorus, less than 0.0257ο Sulfur, rest iron

20th

consists. - as

2. Coated electrode with lime-based or rutile-acid coating for cold welding of lamellar or globular gray cast iron to achieve the weld metal specified in claim 1, characterized in that the alloyed core wire consists of

35 20 to 50 7o TiO ₂ , half of which has been exchanged for Na or K titanate
can be,
10 to 20% CaCO ₃ ,
5 to 10 7o feldspar,
up to 10 7 ₀ CaF ₂ ,
up to 10 7o ferromanganese with 0.17 ₀ carbon

nor from the following elements in the form of metals or ferro alloys in the specified There are limits:

15 to 35 7o vanadium,
0.1 to 77 "boron,
optionally 1 to 20 7o niobium or

Niobium / tantalum,
optionally 0.5 to 6 7o nickel.

4. Core electrode for cold welding of lamellar or globular gray cast iron to achieve of the weld metal specified in claim 1, characterized in that in tubular wires made of steel strip, consisting of

0.05 to 0.15 7o carbon,

up to 0.20 7o silicon,
0.3 to 0.5 7 "manganese,
less than 0.025 7o phosphorus,

less than

> υ, j 7 "manganese,
0.025 7o phosphorus,
0.0257 ₀ sulfur,
Remainder iron,

0.03 until 0.15% Carbon, 0.10 until 0.50% Silicon, 0.30 until 0.80% Manganese, 5 until 11% Vanadium, 0.05 until 0.15% Boron, possibly 0.05 until 2.0% Niobium or Niobium / tantalum, possibly 0.3 until 1.5% Nickel, less than 0.025% Phosphorus, less than 0.025% Sulfur, rest iron

introduced a filling in a weight proportion of 20 to 35 7o of the total electrode weight is made of vanadium, boron, optionally niobium or niobium / tantalum, optionally nickel in metallic Form or as master alloys and fluxes.

40

consists.

3. Electrode according to claim 2, characterized in that the core wire is unalloyed and made of

0.03 to 0.15% carbon,

up to 0.20 7o silicon,

0.3 to 0.7 7o manganese,

less than 0.20 7 "copper,

less than
less than

Manganese 0.20 7 "copper, 0.0257 ₀ phosphorus, 0.0257 ₀ sulfur, remainder iron

55

and the calcareous coating next to

20 to 35 7o CaF ₂ ,

15 to 45 7o CaCO ₃ , which up to 50 7 ₀ can be exchanged for SrCO ₃ or up to 100 7 ₀ for BaCO ₃ ,

up to 10% SiO ₂ , up to 10 7o Fe ₃ O ₄

or the rutile acid coating next to

For cold welding of cast iron with lamellar or globular graphite, coated electrodes are used known that in the connection a weld metal of

0.42% C,
0.65% Si,
0.387 ₀ Mn,

7.37ο V, ■ · ■ ■ ■
0.157ο Cu,
0.017ο Ni,
, 0.017ο Cr,
-. Remainder Fe

remove [»New type of stick electrode for cast iron cold welding«, Schweiß und Schneid, 17 (1965), Issue 1, pp. 26 to 28].

^{With this filler material, hardnesses of 550 to 700 kp / mm 2} HVl were obtained in connection welds on lamellar cast iron in the transition from welding to casting. The microstructure of the transition from welding to casting consists of martensite and ledeburite. In contrast, the weld layers had a ferritic basic structure in which vanadium carbides are embedded.

The pure weld metal of this vanadium alloy electrode had a tensile strength of 49 to

it
as
Ba-

52 kp / mm ² , with a measuring length of 1 = Sd an elongation of 29 to 30%. While lamellar gray cast iron with a ^{strength of 18 to 30 kp / mm 2 had} tensile strengths of 17 to 34 kp / mm ² in its connections with this electrode and the fractures mostly occurred in the cast, the joint welds on globular gray cast iron had 38 to 42 kp / mm ² Strength Tear strengths of 40 to 43 kp / mm ² with elongation values of 6 to 9%.

The fractures occurred partly in the transition, partly in the cast body itself. The welded joints have the disadvantage that they are sensitive to cracks in the hardness transitions from the weld to the cast. This brittleness is particularly evident when welding at room temperature without preheating. In rigid joint welds, at the slightest tensile stress caused by restraints, a tearing of the seam in its center can be observed. The embrittlement of the weld metal and the transition from the sweat of the cast iron could be reduced, if not at room temperature but after preheating at 300 welded to 45O ⁰ C was added. Occasionally, cracks in the weld metal or in the transition could not be completely avoided at these temperatures.

The object of the invention is now to find suitable filler materials for cold welding of lamellar or globular gray cast iron that is a weld metal with 5 to 10% vanadium, 0.005 to 0.1% boron, optionally 0.05 to 2% niobium or niobium / tantalum . and optionally 0.3 to 1.5% nickel.

To solve this problem, according to the invention for cold welding under protective gas, a naked Electrode suggested that out

0.05 to 0.20% 0.15 to 0.80% 0.4 to 1.0%
5 to 11%
0.005 to 0.12%, optionally 0.05 to 2.2%

possibly 0.3
less than
less than

Carbon, silicon, manganese, vanadium, boron.

Niobium or niobium / tantalum, up to 1.5% nickel, 0.025% phosphorus, 0.025% sulfur, Remainder iron

consists. .

For welding without protective gas, however, a coated electrode with a lime-based or rutile-acidic electrode can also be used Sheathing can be used in which the alloy core wire is made of ... ■ '■' ■

0.03 to 0.15%
0.10 to 0.50%
0.30 to 0.80%
5 to 11%
0.05 to 0.15%
optionally 6.05 to 2.0%

possibly 0.3
less than
less than

Carbon, silicon, manganese, vanadium, boron,

Niobium or niobium / tantalum, nickel, 0.025% phosphorus, 0.025% sulfur, the remainder iron

up to 1.5 %

exists and deposits a weld metal of the above composition. The core wire of the covered electrode can also be unalloyed and made of

0.03 to 0.15% carbon, ".

up to 0.20% silicon, '

0.3 to 0.7% manganese, less than 0.20% copper, less than 0.025% phosphorus,

less than 0.025% sulfur,

. Rest. Iron. .

exist, with the calcareous coating next to

20 to 35% CaF ₂ ,:. '

15 to 45% CaCO ₃ , which is up to 50% by SrCO ₃ or ■ /.,. . up to 100% can be replaced by BaCO ₃ , up to 10% SiO ₂ , '·. ■ ·.
up to 10% Fe ₃ O ₄

or the rutile acid coating next to

20 to 50% TiO ₂ , half of which can be exchanged for Na or K titanate,

10 to 20% CaCO ₃ , · . ■

5 to 10% feldspar, ^

up to 10% CaF ₂ ,
up to 10% ferromanganese with 0.1% carbon

nor from the following elements in the form of metals or ferro alloys within the specified limits consists:

15 to 35% vanadium,

0.1 to 7% boron, ■ '-.-

optionally 1 to 20% niobium or niobium / tantalum, optionally 0.5 to 6% nickel. . ■ · .

According to the invention, however, it is also possible to use a core electrode in which tubular wires made of steel strip, consisting of

0.05 to 0.15% carbon,.

up to 0.20% silicon, 0.3 to 0.5% manganese,

less than 0.025% phosphorus,

less than 0.025% sulfur,

Remainder iron,. ,

a filling is introduced in a weight proportion of 20 to 35% of the total electrode weight, which consists of Vanadium, boron, possibly niobium or niobium / tan

, Valley, optionally nickel in metallic form or "· ^l as master alloys, as well as fluxes is.:

All of the aforementioned electrodes deposit a weld metal of the aforementioned composition.

The welding electrodes according to the invention contain 5 to 11% vanadium and 0.005 to 0.12 or 0.15% boron. This increases the sensitivity to

Cracks in the transition from cast to weld metal are significantly reduced. The appearance of diminution

^x the susceptibility to cracking can be increased by adding 0.05 to 2.2% niobium or niobium / tantalum. The welds containing boron or niobium / tantalum have

In the transition from gray cast iron to welding, hardnesses of 250 to 350 kp / mm ^a HV1. The weld metal itself has a strength of more than 42 kp / mm * when welded ^{at preheating temperatures of more than 150 ° C}

will. Circumferential welds on pipes made of GGG 42 out of 6 to 10 mm wall thickness could be free of cracks connect after preheating to 150 ⁰ C. By adding boron or niobium / tantalum, it is possible to work with a lower preheating temperature than when the welds are boron or niobium / tantalum-free. It was also possible to weld connections of the steels St 52 or St 37 with globular gray cast iron of more than 42 kp / mm ² without cracks. The welded connections did not require any thermal aftertreatment.

The strength of the weld metal can be increased significantly by adding nickel. Amounts of 0.3 to 1.5% Ni bring about an increase in strength in the weld metal of 4 to 15 kp / mm ² . With these electrodes it is possible to weld spheroidal graphite cast iron of more than 50 kp / mm ² , the weld reaching or even exceeding the nominal strength of the cast. In joint welds on GGG 50, strength values of 49 to 62 kp / mm ^{2 were} achieved in the joint seams. "

As welding filler materials according to the invention, bare or coated electrodes come in one of the desired weld metal corresponding composition from the above range into consideration, or it For example, an unalloyed core wire with a sheath containing the alloy elements can be used. The coverings of the electrodes are lime-based

ίο or rutile acid. ''

The diameter of the bare electrode is generally 0.6 to 3.2 mm. With the covered electrode the thickness is 1.7 to 2 times the core wire diameter.

Finally, filled tubular wires of the type mentioned above can also be used for welding according to the invention of lamellar or globular gray cast iron.

Claims (1)

Patent claims: 1. Bare electrode for inert gas cold welding of lamellar or globular gray cast iron for Achieving a weld deposit with 5 to 10 7o vanadium, 0.005 to 0.17o boron, optionally 0.05 to 27o niobium or niobium / tantalum and optionally 0.3 to 1.57o nickel, characterized that the electrode is off