JPS58141893A - Co2 shielded flux cored wire for hard facing - Google Patents

Abstract

PURPOSE:To improve the hardness of build-up metal and welding workability, by enclosing a flux incorporated with prescribed ratios of rutile, iron oxide, zircon sand, etc. in a sheath of a mild steel sheath at a prescribed packing rate and flux hardness. CONSTITUTION:A flux contg., by weight, 18-30% rutile, 0.5-10% iron oxide, 0.5-5% potash feldspar, 0.5-10% zircon sand, 2-10% alumina, 0.5-3% sodium fluoride, and 1-8% Si, 2.5-22% Mn wherein 2-3.5 Mn/Si, 30-50% Cr, <=8% Mo, 3.6-5.5% C, <=5% total of >=1 kind among V, B, Nb, 5-15% Fe. This flux is packed in a sheath of a mild steel strip in such a way as to attain 0.1-0.3 rate of packing expressed by the equation I and >=2 product of the value FH converted to the flux and the rate of packing J expressed by the equation II. Thus, the wire has excellent weld workability and the build up metal exhibits high hardness.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to automatic and semi-automatic CO and shield flatus insertion wires for hardening.

Civil engineering and construction machinery uses hardened inner fill for bridge parts, but coated arc S welding has been frequently used for materials that require high hardness, such as the cutting edges of heavy excavators. . Such parts are required to have a hardness of Hmaro 00 or higher, but conventional Solirad wire for C02f shields has a hardness of Hmaro 45 due to the wire OII structure.
Only those up to 0 degrees are commercially available, and there are no flux-cored shear wires that are easy to work with.
It has been considered difficult to automate or semi-automate welding using shielded arc welding.

In the present invention, the overlay metal exhibits a high hardness of Hma 550 or more,
The present invention also provides a flux-cored wire for shielding, which has excellent welding workability in terms of arc condition, slag encapsulation, and slag O peelability.

That is, the present invention uses an annealed copper strip material as an outer skin, and contains rutile 18 to 3 (1, iron oxide 0.5 to 109 g,
Potassium feldspar 0.5~S*, zircon sand 0.5~10%
, alumina 2-1 (1, fluoride saw 0.5-3-0t deoxidizer 2 alloying agent 811-89G, klba
2.5-22 Is and Mu/81 = 2.0-3
5.

Cr 30~5011G 1Mo In or less, C3,6
~S, 554T, V, II, Nb, the sum of one or more of two or more types is 5- or less, and the flux composition includes r.5 to 154, and the filling rate (J
) is in the range of 0.10 to 0.30, and the product of the mass conversion value (FH) calculated using formula (2) and the filling factor (7) calculated using formula (1). This is a C02 shield 7 lux shear wire for hardening sensation, which is characterized by blending a deoxidizing agent and an alloying agent for the included flux so that the ratio is 2.0 or more.

Filling rate G: Weight of outer steel strip in shear wire with lux F = 7 lux Weight of 7 lux in shear wire PH-0,I
C7%) + 0.0811161G) + 0.1 Mm (
14+ 0.18Cr&Ij+ 0.28MaflQ+
0.07 V% + 1ejG) + 0.07Nb @ (2) In the present invention, annealed copper strip material is CO, 04 to 0.191G, 81≦0.3% by weight,
kllMO,4-, the remainder refers to substantial KF. and impurities.

Hereinafter, the main source 1111 will be explained in detail.

First, with regard to rutile, it increases the stability of the welding arc, improves the slag encapsulation of the weld bead surface, smooths the rising angle of the weld toe, and improves the V-doped overlapped part (no valleys occur). ) K contributes. The amount added is 18
If it is less than -, there is no effect of improving fI# contact workability such as arc stability, slag peeling, and switch prevention.
In the 30-year trend, it becomes difficult to add K as a deoxidizing agent and alloying agent in quantity in order to obtain a high-hardness overlay metal when considering the addition of other slag agents. Therefore, the range of the appropriate amount of rutile to be added was set as 18 to 30.

Iron oxide is effective in adjusting slag viscosity and improving arc stability and slag removability, but O,
If it is less than S*, the slag will lack viscosity and fluidity, resulting in slag O.
Encapsulation properties are poor, smooth peads cannot be obtained, and large grains of sufu 9 are produced.
．． If the temperature exceeds 1o, the slag becomes too viscous and fluid, and the slag is not evenly coated in the bead, resulting in insufficient slag in the center of the bead and flowing into the toe of the bead. , bead rise] The angle is also large and the bead has a slightly oversized peed, and there is a dent (becomes a valley) in the overlapped part of the bead, which makes the smooth fleshy surface look feminine. Therefore, the range of the appropriate amount of iron oxide to be added is 0.5 to 1°.

Regarding potash feldspar, it is effective in adjusting the potency, arc stability, slag viscosity, and fluidity, but if it is less than 0.5, the effect is not recognized, and if it is more than 5, there is a large amount of -5. This is undesirable, as the slag fluidity is excessive, the slag encapsulation is poor, and large grains of snow ivy are generated. Therefore, the range of the appropriate amount of potassium feldspar to be added is from o, s to 5-.

Zircon sand is effective in adjusting the viscosity and fluidity of the slag, and since the arc is stable and spreads, the radius of the bead is widened and a bead with good conformability can be obtained. However, the effect is not observed below 0.5-, and l
If it exceeds o, the slag viscosity becomes excessive, which worsens the formation of peads. Therefore, the range of the appropriate amount of zircon sand to be added is 0.5 to 10.

Al construction involves adjusting the arc strength and improving slag removability.
However, if it is less than 2, no spreading effect is observed, and if it exceeds 1 OI, the strength of the arc becomes excessive, and the slag 2! The appropriate amount of aluminum added was determined to be between 2.0 and 10. Fluoride saws are effective for arc stability and slag removability. However, if it is less than 0.5, the arc becomes stable in the middle and below, and the amount of slag generated is not suitable, and if it is more than 3, the arc becomes unstable due to insufficient viscosity of the slag. The appearance was not pleasing, so the appropriate amount of sodium fluoride added was set at 0.6 to 3.・Next, we will explain deoxidizing agents and alloying agents.

81. as a deoxidizing agent. It is essential to add C as an alloying agent to obtain the hardness of the overlay metal.

Cr # Me a V g B g Nb and other 81
．． Mn also contributes to hardness, and by appropriate combination of these,
Regarding fist s1, which is inexpensive, has little variation in hardness, and has a hardness of 81550 or more with good cracking resistance, it has a spreading acid effect as well as an effect of adjusting the fluidity of molten metal. There is. Although the deoxidizing effect is great, if it is less than 191, the effect will be small and fa holes and pits will occur due to insufficient deoxidizing, making it unsuitable.If it is more than 8, the peed appearance, slag peeling, etc. will deteriorate and it will not be suitable. The appropriate amount to add is 1 to 8 mo.

As for ``Tie'', it is effective as a deoxidizing agent and an alloying agent like ST, but if it is less than 2.5, the effect is less and blowholes and pits occur due to insufficient deoxidation, making it unsuitable.
Due to insufficient content in the deposited dissimilar metal, the variation in p hardness becomes large. If it exceeds 22-2, the slag peeling becomes poor and
Small particles are formed on the surface of the bead, and the appearance of the bead is unfavorable.Additionally, no effect can be expected as an alloying agent, and the addition reaches a saturated state. Based on the above, the appropriate addition amount range is 2.5 to 22 IJl.

However, the addition of 81 or Maji1 alone is inappropriate. Adding only 81 without adding 0MX increases the Fisi. As a result, the molten pool becomes boiling, which not only impairs welding workability, but also causes blowholes to occur. K becomes. If 81 is within the appropriate addition amount, the boiling molten pool will be in state 4.
Mu/81 gradually subsided as bMl& was added.
Welding workability is the best when the value is in the range of 2.0 to 3.5, and there are no blowholes or pits.

Therefore, for the addition of deoxidizer, Mu/I l is 2
．． It is essential that it is 0 to 3.6.

Regarding Cr ll IC, K is 30% in order to obtain an inner filler metal with a hardness of 87550 or higher, which is extremely effective in maintaining and stabilizing the hardness of the filler metal, considering crack resistance and economic efficiency. It is necessary to add more than that, but! If it exceeds S〇-, retained austenite will occur)i1!
The appropriate addition amount range is 30 to 50, which is not expected to have any effect on the surface of the metal and is unfavorable in terms of the cracking sensitivity of the overlay metal.

Regarding the lid, when the hardness is stabilized and heat treated,
It is also effective in preventing softening seen in the heat-affected zone of weld metal. However, if it exceeds 8, the effect is not expected. Therefore, the range of the appropriate amount of Me to be added is set to be 8 or less.

CK') is the most effective method for economically obtaining hardness of the overlay metal, but on the other hand, it deteriorates the cracking resistance of the overlay metal. In order to obtain a textured metal with a hardness of Hma 550 or more, it is necessary to add 3.6% or more of S, but if it exceeds %S, the cracking resistance of the overlay metal will seriously deteriorate. Therefore, the appropriate amount of C added was 3.6 to S, S*. In addition, C
If L-graphite is used for addition, it will not only cause unevenness to occur when mixing the flux or filling it into the wire, but also impair the cracking resistance of the overlay metal, so high carbon ferroalloy medium carbide powder is used. It is desirable to use it.

When adding materials such as lil, wh, Cr, M, etc. in the form of ferroalloy, the iron contained in these becomes the source of r in the 7 lux, of course; Addition of jiKF/powder is also effective in improving arc stability and peed gloss. However, to obtain high hardness, hardening elements should be added preferentially.)
The total iron content is 5 to 15%, which is sufficiently effective for educating welding workability. Therefore, the appropriate amount of F. to be added should be in the range of 5 to 15-.

Furthermore, in order to obtain a fleshy metal with a hardness of avsso or higher, it is necessary to have a relationship between the combination of deoxidizing agent and alloying agent and the filling rate (ratio of flux to the total amount of wire).
) When the filling rate (η is less than 0.10), a slag forming agent to adjust welding workability, an arc stabilizer, and a deoxidizing agent to prevent blowholes and bits are used.

Contains an alloying agent that gives hardness, and the hardness of the overlay metal is Hmas5
It is very hard to maintain a value of 0 or more and obtain good welding workability. On the other hand, if the value exceeds 0.30, the produced wire will not easily break, and stable 1#-S* cannot be performed. * Based on the above-mentioned 0.0, the range of the distance between the 9 full and horizontal cars can be defined as 0.10 to 0.30 as shown in equation (1).

J: Filling rate G: Weight of outer steel strip in flux-cored 9 wires r: Weight of 7 lacs in 7 lats-cored pre-wires On the other hand, the relationship between the chemical composition of overlay metal and hardness is expressed by the formula for the carbon content of steel. It is known that a relatively good response can be obtained by repurposing. However, it has not been possible to estimate the hardness of the overlay metal from the mixed flux of the 7 lux wire, and the composition of the overlay metal has been determined solely through trial and error.

In the present invention, the ratio of the deoxidizing agent and alloying agent contained in the 9 wires containing 7 rats to the mixed flux is 5.
An experiment was conducted to make wires by varying the hardness f in the range of 016 to 70-9, obtain many build-up metals, examine the hardness of these metals, and estimate the hardness f of the build-up metals from the blended flux.

The blending ratio of the slag forming agent used in this experiment was rutile 1
9~31-0 Iron oxide 3~51! , potassium feldspar 1, S~2
・S arrogance, zircon sand 1.5~tS-, AkRtLs
~2. S%, 10.9 to 1.111 degrees of sodium fluoride, and 3 to 5 degrees of lime carbonate were mixed, and a deoxidizing agent and an alloying agent were added to this blended slag forming agent at the above ratio and used as the final flux. . In addition, the 7 lux O-helm horizontal wheel was set to (Li2) and the number of wires was set to 4!1.8.

S* conditions are 350 m, 32 V, 40 f
fi/mln dnu warm l! Let zooo℃ be co, s
c Weight: 0 J/xmin, 4 layers are stacked on a mild steel plate, 4
The chemical composition and hardness of the sensuous metal were tested. As a result, in addition to the coal buildup amount, hardness, and OIl ratio of the overlay metal,
By summarizing the proportions of the added deoxidizing agent and alloying agent in the steel as shown in equation (2), the flux hardness conversion value (FH), which is a guideline for estimating the hardness of the overlay metal, can be obtained. A friend who discovers things.

FH-0,8C@l+o,o 8 gt 6G)+0.
1 M OflE)+α11Cr@10α2 S Mo[
+0.07 V%+1(1)+Q,07)ffi%・
-(2) 1&, fjl- Even in the 7 lux formulation, changing the hardness of the p overlay metal by changing the filling rate (J) is ll; b@7, ? KC4s-8121. M
u5 flk, IF@5 flk, Cr4
Using a blended flux containing 011G, Mo 6 , V 1 %, the filling rate a) was 0.10, 0.15°0.
20, 0.25, 0.30 and 7 ('r diameter 1.6
wm O flux-containing] wire was prototyped and overlaid under the same welding conditions as above, and the hardness of the overlay metal was examined. The results are combined with the above results and organized in terms of FHX J and hardness, and are shown in Figure 1.
This is the hardness when Q and 30KgR are removed from LIG. As a result, the hardness of the overlay metal that can be stably obtained by Hma 550 or higher is obtained only if the product of the 7 lux hardness conversion value (flower) and the filling factor g) is 2.0 or more, that is, FHXJ≧20. Then, 1. In addition, after explaining the above, the composition of 97 lux is KN! There is no harm in adding a small amount of ON for the purpose of improving performance, etc., and fluorite has a lot of 0 properties in terms of slag viscosity, melting point, etc.
11 Materials used in the 11th century are slag, lead glass, bismuth oxide, etc., which are known as slag removal improving materials, and carbonated lime, Madanesha clinker, etc., which are known as basicity adjusting materials. These raw materials need to be added to improve performance such as welding workability, but adding these raw materials may have disadvantages such as high cost or reduction in alloying agent ratio. There is also. Therefore, if there is a concern that the hardness will decrease due to a decrease in the addition ratio of high-cost and medium-cost alloying agents, it is not necessary to add these raw materials O.

Next, the effects of the present invention will be explained in more detail based on Examples.

Example collection 11! ! The flux with the composition shown in No. 21NK
Filling an annealed copper strip material with the composition shown at the filling rate shown in 111K,
Grease was left on the wire of wire m1ll■.

Table 2 Chemical composition of annealed copper strip material No. 1! I! In 41. -410 are examples of the present invention,
Comparative examples of A11 to Todoroki 17a are shown. These 4
Welding workability and hardness tests were conducted on 9 wires of 7 lux of l-Alr using the welding conditions and base metals shown in Tables 3 and 4. The results are shown in No. 511. Welding was performed using string bead overlay welding.

Table 3 mm condition 6th table Welding workability and hardness test 0 good Δ medium poor arc stability, slag encapsulation, slag peelability, peed appearance,
Both the welding workability, such as the amount of ivy generated, and the hardness of the metal were satisfactory. However, the purpose of the present invention could not be fully achieved for comparison wires Mu11 to AI7.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the relationship between the value of (FH) and the hardness of overlay welding.

Claims (1)

[Claims] Mild steel strip material is used as the outer skin, and the inside is made of Ruti-418 in terms of weight ratio.
~30g, iron oxide o, s ~:to*, *IJ feldspar o,
s~s嗟、Jilheunsan）'0.5~101 2~10Is, 0.5~3T of soda fluoride, and 1 deoxidizer
As an alloying agent, 811~ss, -λS~22-Dekari Mm
/Ill = 2.0-3.5, Cr 30-50
'16-Me 8- or less, C36~5.5%, V, Seal, 16 O, one type of trench nine, the total of two or more types is 591
1 or less, with a flux composition containing r 5 to 151G, (
The filling factor calculated by equation 1 (η is in the range of 0.1O to 0.30!iiK, and the flux conversion value (FH) calculated by equation (2) and the filling factor calculated by equation (1) (Deoxidizing agent for flux included so that the product with ■ is greater than or equal to LO,
``The combination of alloying agent is 41I image and C for hardening flesh feeling.
O, shield flex wire: filling rate G weight of outer band steel in near lux wire r weight of 7 lux in near lux wire FH = 0.8
0@l+ 0.08111(*+ 0.1 Mm%+
0.18 Cr(59+ 0.25 Ms@$+ 0.
07 V%+I1%)+0.07Nb(1) “-”
(2) FH: flux hardness conversion value C: weight ratio of carbon contained in flux 81: weight ratio of silicon contained in flux -; weight ratio of manganese contained in flux Cr contained in near-lux Chromium weight ratio: weight ratio of molybdenum contained in flux V: weight ratio of vanadium contained in nifututas B: weight ratio of molybdenum contained in rough flux. Weight ratio Nb of 1on
: Weight ratio of two otsu contained in flux