DE1533539C - Filler materials for cold welding of lamellar or globular gray cast iron - Google Patents

Description

0.05 to 0.20% 0.15 to 0.80 7o 0.4 to 1.0 7o 5 to 11%
0.005 to 0.12 7 ₀ optionally 0.05 to

possibly 0.3
less than
less than

Carbon, silicon, manganese, vanadium, boron, 2.2 7o niobium or

Niobium / tantalum, 'up to 1.5 70 nickel,. 0.025 7ο phosphorus, 0.025% sulfur, the remainder iron

consists. .

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

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

20 to 50 7o TiO ₂ , which is up to half by Na-. or K-titanate
^v can be
10 to 20 7o CaCO ₃ , ■
5 to 10 7o. Feldspar,

V to 10% CaF ₂ , ■ · ■; -. ; ^. .

! • '■ «to 107o ferromanganese with 0.17o carbon

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

15 to 35% vanadium,
0.1 to 7% 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 "in claim 1 specified weld metal, characterized in that in tubular wires made of steel strip, consisting of

0.05 to 0.15 7o carbon,

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

less than . 0.025 7 ₀ sulfur,
Remainder 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% silicon,

0.3 to 0.7 7o manganese,

less than 0.20 7 ₀ copper,

less than
less than

0.20% copper, 0.0257 ₀ phosphorus, 0.0257 ₀ sulfur, remainder iron

55

and the calcareous coating next to

20 to 35% CaF ₂ , ·

15 to 45 7o QaCO ₃ , which is up to 50 7 ₀ by SrCO ₃ -. or up to 1007o

BaCO ₃ can be exchanged. can,

up to 10% SiO ₂ , up to 10% 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 known, which in the connection a weld metal of

0.42% C,
0.65% Si,

0.387 ₀ Mn,, ν,.

0.15% Cu,.

ο, οι 7ο Ni,:

0.01% Cr, ■■■ · _-:

- remainder Fe, · '- .. ·

remove [»New type of stick electrode for cast iron cold welding«, Welding and cutting, 17 (1965), issue 1, pp. 26 to 28].

With this filler material, hardnesses of 550 to kp / mm ^a HV1 were obtained in joint 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

52 kp / mm ^a , with a measuring length of 1 = 5d 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 casting. 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 welding to gray cast iron could be reduced if welding was not carried out at room temperature but after preheating to 300 to 450 ^° C. Sometimes 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 create suitable filler materials for cold welding of lamellar or globular gray cast iron which have a weld metal with 5 to 10% vanadium, 0.005. optionally 0.05 to settle to 0.1 ° / ₀ boron, up to 2% niobium or niobium / tantalum, and optionally 0.3 to 1.5 ° / ₀ 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, nickel, 0.025% phosphorus, 0.025% sulfur, The rest of the iron trode 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,

. Remainder iron

ίο ■■ '.' ..

exist, with the calcareous coating next to

20 to 35% CaF ₂ ,

15 to 45% CaCO ₃ , which can be exchanged up to 50% by SrCO ₃ or up to 100% 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 the case of tubular wires made of steel strip, consisting of

up to 1.5 »/,

exists. · '■■: ■ -. ■■ _: .: ··'. ·. ■ - / ■; ■ ■; . .. _"-;, ¹ V. '■ - In order to weld without protective gas but also a coated electrode can, basic- or rutilsaurer sheath used, in which the alloy core wire.'...

0.03 to
0.10 to

0.15%
0.50%

Carbon, silicon,

0.30 to 0.80% manganese,

5 to 11%
Q.05 to 0.15%
optionally 0.05 to 2.0%

, optionally 0.3
less than
less than

Vanadium, boron,

Niobium or "niobium / tantalum, up to 1.5% nickel, 0.025% phosphorus, 0.025% sulfur, remainder iron 0,

: less than
less than

0.05 to 0.15% carbon,

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

! 0.5% manganese, 0.025% phosphorus, 0.025% sulfur, Remainder iron,

exists and deposits a weld metal of the above composition. The core wire of the covered electronics 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

; _t . tal, optionally nickel in metallic form or ^v · 'as master alloys and fluxes. :

All of the above electrodes deposit a weld metal of the above 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 ¹¹ HV 1. 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, naked 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 or rutile-acidic. ','

The diameter of the chopped electrode is generally 0.6 to 3.2 mm. In the case of the covered electrode, the thickness is 1.7 to 2 times the core wire diameter. _: "

Finally, “filled” tubular wires can also be used of the above type according to the invention for welding. Used of lamellar or globular gray cast iron will. ■ ''. '·' · '■ "■" ■. ■

Claims (1)

Patent claims: 1. Bare electrode for inert gas cold welding of lamellar or globular gray cast iron for Achievement of a weld deposit with 5 to 10 7o vanadium, 0.005 to 0.17o boron, optionally 0.05 to 27o niobium or niobium / tantalum as well as possibly 0.3 to 1.57o nickel, thus marked i ch η e t that the electrode is off.