DE1758922C - Cored wire electrode for wear-resistant overlay welding of steel parts - Google Patents

Description

The invention relates to a filler wire electrode Wear-resistant build-up welding of steel parts made from a mixture filled with powder Sheath consists of low carbon steel

The cored wire electrode according to the invention is mainly used for mechanized submerged powder build-up welding and can also be used for Schuizgas overlay welding

The use of mechanized overlay welding of the aforementioned products is general an alloyed chromium-molybdenum wire and a chromium-silicon wire are known. The creation of such a Wire made from high-strength steels is expensive because the wire is annealed several times and then during the Draw.is must be pickled. Another disadvantage is the deep penetration inherent in submerged arc welding, which forces the build-up of weld layers to increase and increases wire consumption

More economical and effective is the well-known cored wire electrode, which has been widely used for overlay welding of rolls and similar products and which contains 40% ferrous tungsten, 13.5% ferrochrome, 3.5% ferrovanadine, 2.5% frromanganese, 2% ferrosilicon and 0.8% graphite. This wire produces a weld metal which contains 0.35% C. 0.80% Si, 0.9% Mn, 2.5% Cr, 8.5% W .. 0.3O ¹ V _n V. The wear resistance of the welded-on layer is very high. However, it has significant disadvantages, which consist in the fact that the resistance to cracking in the event of multiple heating and cooling (thermal resistance) is low and the weld is difficult to process. The first circumstance often leads to the crumbling of the surface of welded-on whales as a result of the development of a network of cracks. The cells of the well-known filler wire electrode are available

mainly because of the high content of expensive tungsten

and the great expense of grinding

difficult to crush materials high; that

Ferro tungsten powder is 30% more expensive than lumpy

Ferro tungsten, still higher ' ¹ ^ "^ ^e ^" ^de >

by reduction, gained, WoK ™ P ^ ^ver J

Purpose of the invention .st mc elimination dr _fcl -

called drawbacks _beg _ _{abe zuerun} de Einder invention cherishes de task ^ ^ nindc one,

to create .ο flux cored wire, dι at e.nerru tively small consumption ^ ™ ^ "^ the conditions the large amount of hard workable ^ [™? ^(™™ ^ £, better thermal W.dersUndsfahgkeU good,

.5 Machinability and high wear resistance gKeil ü ,, Weld metal at high operating temperature. üren ,, -

währleislel. p ;; uArch, _P \ _P i, r ■

This task is carried out ^by _ _t ^ei "f, ^"" ^d ^ ^l ^ ^e _s ^kl _c ^r ': ¹ ·· for overlay welding of rod parts de a, us u,

™ sheathing aas low-carbon steel and e ", _; Filling consists of a powder form ,, _; Mixture composed, which from Ferrochn, Ferromolybden. Ferrovanadin, ferrosilicon, fen mangan ', sodium siluorosilicate and metallize

Chromium and iron powder is dissolved he ·, dun is ^ convention under characterized in ύ mentioned components DAT the mixture in the following Pro / entvcrhältnissen to total weight of (, represent · meimes: 15 to 21% ferro-chromium, ft t.

7%> erromo! Ybdän, 3.5 to 4.5% Ferrovanaii · .. 2.5 to 3.5% ferrosilicon, 2 to 3% Ferromanf .. · 4.5 uriumfluorosilikat to 6.5% N, 4 to _5/0 MC, lischcs Chrome. Remainder iron, and dab aas uemu., ·, 3.i to 37% of the total weight of the F-ulldral ..,

electrode is. ctWrvipl H r ι

In the following, cm execution example is the!

Find described in detail.

The fulldrant electrode according to the invention is .. · _: ·. made of a band of low-carbon steel.

which serves as a casing, which is filled with a pulverulent mixture in such a way that the degree of filling (the ratio between the Ciewichi of the mixture and the total weight of the IWk trodc; id wire) is 33 to 37%.

The components of the mixture> with their ratio to each other are selected in such a way that with the wire according to the invention Material welded under silicon-coated welding flux has the following composition: 0.2 to 0.3 / o

Carbon, 0.4 to 0.8% manganese, 0.9 to 1.3 silicon _0. 4.8 to 5.5 ", chromium, 0.3 to 0.6% vanadium, 0.9 to 1.3% molybdenum, at most 0.04 / ₀ sulfur and phosphorus, and has properties that match the thermally treated and high thermal mix Resistance-marked tool steel, which is used e.g. for hot pressing and compression molds for die casting, should be as close as possible.

Preventing cracking and achieving

^{6> 1 of} the structure of bainite (needle-like troostite) in the weld metal are ensured by a slightly reduced carbon and molybdenum content and increased silicon content compared to the known cored wire electrc of this type.

The very difficult-to-melt metallic elements present in the mixture also play a certain role Chromium, which contributes to the formation of nuclei during crystallization.

i 758 922

The welding with the example according to the invention

The wire is made under low-silicon welding powder. A cored wire electrode is used

that for example from 22% SiO ₂ , 29 ° / ₀ CaF ,, 29 ⁰ I ₀ core filling from a mixture (m weight percent)

AU) ₃ , 6% CaO, 11% MgO and 3% K ₂ O consists of 17.4% ferrochrome, 4.2% metallic chromium

on a product heated to 350 to 380 ° C. Here- 5 6.3% chromolybdenum. 3.5% ferrovanadine 2, o / "

A weld metal hardness of HR, 42 to 46 ferrosilicon, 2.1% ferromanganese, 5.0 / ₀ Natnum-

jmi complete absence of gas pores, cracks, slag fiuorosilicate, remainder iron powder consists ...

_{i; il!} > conclusions and other errors guaranteed. When surfacing with the said

V Wear resistance factor of the weld metal for reed wire of 3.2 mm diameter on low-carbon

hung under lubrication under ordinary working steel ¹⁰ at 320 A welding current undί 27 V arc

di d Klb i hdlih P ng pointed the Schwe.ßgut 'ο · ^^ chemical

hung under lubrication under ordinary working steel at 320 A welding amperage g

The conditions of the piston of a hydraulic press showed the weld metal to be 'ο ^^ chemical

: ". [ _Rug 6.1. Composition on: 0.227 ₀ C, 5, Of ₀ Cr, Ii ₍₀

The resistance to cracking characterizes .. Mo, 0.3% V, 0.5% Mn, 1.0% S .. D.e Schwe.ßgui-

; ' Final test results: After 50 cycles the hardness is 43 HR ₁ -. .,-egg

■ rwarming to 80O ⁰ C and cooling in the water ¹⁵ It can be seen that the invention emc

_t with a test piece made of steel with 0.1 ° / ₀ C, 2.5% Cr, flux-cored wire electrode, oie without use

xs% W Mnd 0.3% V are the total cracks made of ferro-tungsten and with little wear

2-iOmm long, in which (with the eriindungs _b jmäßen of alloying admixtures Ferrocnrom, r-ERRO-

L-raht welded good but only 10 mm. molybdenum, ferrovanadine, ferrosilicon. ^ ^r r ° man-

The lower critical point of the weld metal, ^so gan) the best thermal resistance (loading

r, nd the heating is 822 ° C. resistance to cracking bc; multiple adults

The one for the mechanical processing of the with the mungings and cooling), a good machinable-

according to the invention wire welded on rollers wedge (the time required for the mechanical "eartei-

The time was spent thanks to the better machinability of parts that were

; n% shorter than ^{would be melted when welding with the * 5} wire, is 30 / “lower

known wire than with the welded on with the known wire

For a better understanding of the invention, a th divider) and a high wear resistance of the concrete work example for the invention "welding gas (wear.

j; em appropriate Fülidfahtele'itrode cited. ensures.

Claims (1)

Claim: Cored wire electrode for wear-resistant overlay welding of steel parts, which consists of a casing made of low-carbon steel and a filling that is composed of a powdery mixture, which consists of ferrochrome, ferro-molybdenum, ferrovanadium, ferro-silicon, ferro-manganese. Sodium fluorosilica, as well as metallic chromium and iron powder, is characterized by the fact that the components mentioned make up the mixture in the following percentages to the total weight of the mixture: 15 to 21% ferrochrome, 6 to 7% ferromolybdenum, \ 5 to 4.5 ⁰ Z ₀ Ferrovanadm. 2.5 to 3.5% ferrosilicon, 2 to 3% ferromanganese, 4.5 to 6.5% sodium fluorosilicate. 4 to 5% metallic chromium, the remainder iron, and that the mixture is 33 to 37% of the total weight of the cored wire electrode.