JPS5861993A - Welding core wire for low temperature steel - Google Patents

Abstract

PURPOSE:To improve the low temp. toughness and high temp. cracking resistance of weld metal by contg. specific ratios of C, Mo, Fe, Al, Ti, Mg, Ni. CONSTITUTION:A titled core wire consisting, by weight %, of <=0.15% C, and 12-22% Mo as well as total <=0.25%>=2 kinds among <=25% Fe, 0.005-0.15% Al, 0.01-0.15% Ti, and 0.001-0.05% Mg in addition to the C and Mo and the balance Ni. The weld metal of good low temp. toughness and high temp. cracking resistance is obtained by such welding core wire, and the core wire per se has excellent suitability to forging and suitability to rolling.

Description

Detailed Description of the Invention The present invention relates to a Ni-based gas V-rued arc welding wire, a submerged arc bath welding wire, or a coated arc welding wire (hereinafter simply referred to as welding core) I for welding low-temperature steel.
/c-related, and in detail, it provides a weld metal with good low-temperature toughness and hot cracking resistance, has excellent forgeability and rollability as a wire or core wire itself, and is stable in plastic processing such as wire drawing. The present invention relates to welding core wires that can be welded.

etsNsas and Ntma communication is 6-9.5
It contains a lot of Ni, and is widely used as a construction material for cryogenic containers and equipment 1, such as container sieves for LNG and liquefied gas. 91GNi steel itself is a material with good low-temperature toughness, showing a good score of 4 in the notch toughness test at -196°C, and its tensile strength is comparable to 70 kgA/' class high-tensile steel. It is desired that the weld metal obtained by welding these materials exhibits low-temperature toughness and tensile strength that are as good as, if not better than, the base metal. Therefore, it is necessary to carefully select the metal materials used for welding.For coated arc welding, AWS-A 5, 11 ENiCrFe-1~
An 8 fathom component system is utilized. However, it is worth recommending as a wire for submerged arc welding. For example, AWS-A5゜14f) ERN is a wire of the same type as the above welding rod.
When using Inconel wire such as iCr-8, f#
The strength of the joint (i) was extremely insufficient, and it also had the disadvantage that hot cracking was likely to occur.

In recent years, wires containing a relatively large amount of MO have been developed as metal materials to replace the Incone V alloy (for example, the
94FrR, 49,277R2゜51-14979
．． 53-49104 etc.).

Submarine arc fI! ! However, as the MO content increases, the forgeability and rollability of the wire itself deteriorates, and the production yield in the wire drawing process decreases significantly. It had the disadvantage that it was an extremely expensive wire.In other words, if vcell cracking occurred during forging or rolling, if it was a large crack, it would be considered a defective product on the spot, but if it was a micro crack, it would be considered a good product and the wire would be drawn. At that stage, the wire may break, resulting in an important production trap V.
occurs. Furthermore, even if it were possible to draw the wire to the diameter of the final product, it is known that minute cracks would remain on the wire surface, and if a corrosive agent remained in these, it would adversely affect welding workability. .

The present invention has been made with attention to these circumstances, and it is applicable not only to various 8m wires such as submerged arc welding, Ml (Jlili, TlGg welding), but also cores for coated arc welding rods. A weld core wire for a wide range of welding, including wires, etc.
The object of the present invention is to provide the above-mentioned metal wire which not only has good forgeability and rollability, but also provides a weld metal having good low-temperature toughness and hot cracking resistance once used for welding. That is, the metal wire of the present invention is C(0,159 [weight q6
, and the following C) and Mo = 12-22 * including tr and other A
/ago, 006~0.15%, Ti==0.01~0
．． 15, Mg=0.0 (j1 to 0.05), including two or more bridges selected from (A/+Ti+Mg)<0.25, and the U part contains Ni and unavoidable impurities. The main point is that it provides a fIIII metal with good low-temperature toughness and hot cracking resistance, and also has good forgeability and rolling properties in the production of welding wheels or core wire itself. For the above composition, Mn (5chi 1w <5chi).

(If one or more selected from r≦4.8 and Si≦1.6 are added, the joint strength can be improved.
In some cases, it may have an adverse effect on low-temperature toughness, so it is advisable to add Fe in an amount of 25 or less to prevent a decrease in low-temperature toughness.

ye is 1 regardless of whether Cr, Si, etc. are added! Although the following may be added, such a configuration is also included in the present invention. Although C, A/, 'ri, and Mggo function as deoxidizers, deoxidizers other than those mentioned above may be added as necessary, without departing from the basic composition described above. All compositional changes within the limits are within the scope of the present invention.

The reason for limiting the range of ingredients in the present invention will be explained below.

Ni was selected as the basic component because it stabilizes austenite and is essential for improving low-temperature toughness. However, there is a particular restriction on the amount of Ni mixed in. It is sufficient if it occupies the entire amount of shi.

C is an element that increases the strength of the melt and also functions as a deoxidizing agent, but if it is added in excess of 0.15%, it will significantly reduce the low temperature toughness.
The upper limit of C was set at 0.15.

MO not only improves the strength of welded joints (.

It is an element that prevents hot cracking during welding, but this effect is not exhibited when the content is less than 12%, so the lower limit was set at 12%. On the other hand, if f12% is exceeded, the low temperature toughness decreases, and the forgeability and rollability decrease dramatically, but it is sufficient to add az, ri, Mg, etc., which will be described later, to compensate for the decrease in forgeability, etc. Recovery effect IIi cannot be obtained. Therefore, the upper limit of MO was set at 1122.

Ti, A/, MgVi are the most characteristic alloy components in the present invention, and have the function of compensating for the decrease in forgeability and rollability caused by the MO composition. That is, Ti, A1. MgFi is a metal with inherently strong deoxidizing ability, and this deoxidizing ability is thought to have an important influence on the recovery of forgeability and rollability, and the effects of these combinations were investigated using the following procedure. . First, the present inventor* has arrived at a test method for forgeability and pressability. This test method uses a columnar test piece (parallel length HBOwm*diameter of parallel part: 6.OwLl) at high temperature (11!5 in this experiment).
The number of times the screw is screwed under 0°C) is determined by the number of times it takes to break, but when we investigated the relationship between the number of times it was screwed and the occurrence of cracks in actual forging and rolling, we found that the number of times it was screwed was 10 times. In the following cases, cracks occurred frequently, and in cases of 20 times or more, cracks hardly occurred. Based on these facts, it was determined that there was a good correlation between the number of screws υ and the occurrence of cracking, and the following results were obtained: The relationship between the amount and the number of screws was determined.

Figure 1 shows the case of a single combination, and judging from Figure 1, for example, for Ti and A/, the number of twists is 10 times or more, vK.
In order to increase the number of twists, it is necessary to mix it up to about 0.25, and to increase the number of twists to 20, it is necessary to add 0.4 to 0.5.
Unfortunately I had to increase it by 4.

Regarding Mg, we have only calculated values up to 0.025, but at this point it has not yet been possible to increase the number of screws. Therefore, in order to improve forgeability and rollability, the amount of the above-mentioned deoxidizing metal should be 0.25 or more, preferably 0.4 to 0.
．． I found out that I also had to add 596,
When such metals are added with a valence of 0.2.5 or higher, oxidation products are precipitated mainly at the grain boundaries of the weld metal, creating a new problem in that it significantly accelerates the tendency for hot cracking to occur during welding. occurs. Furthermore, when inert gas arc welding is performed using such a wire, the above-mentioned oxidation products are mixed into the slag and have an adverse effect on the properties of the slag. Welding defects such as entrainment and poor fusion are likely to occur.Therefore, regardless of the effectiveness of the above-mentioned deoxidizing metal, if it is not used in an effective I4 mixture, it will become a problem.Therefore, from this aid When I tried mN to get rid of it, - with the addition of 21 each or a combination of 8 of ri, Az, and Mg, #
Even a small amount that does not cause contact defects or hot cracking and does not adversely affect welding workability will increase the number of screws and cause J1! It has been found that the rolling properties are significantly improved. That is, in FIG. 2, (Ti+A/'), (Ti+Mg).

This shows the relationship between the total blending amount and the number of twists when two types of (Mg + A/) are used in combination.
O,007 indicates screw rotation @24, and other combinations are already available at low levels of O,O] ~ 0.02'ip.
C9 indicates the number of twists exceeding 24 times.

Gang lol! , the addition ratio of each element in the experiment shown in Figure 2 is (T
Case 171. In the case of (Ti+Mg), T
i1Mg No. B/1. (A/+Mg) If A//Mg
``8/1 and 17i (0.01qb.

A/<:0.0051! , Mg (0,001) The above-mentioned composite addition effect ki could not be obtained. On the other hand, Ti) 0.1
5, A/) 0.115, Mg) 0.05, slag is not easily generated in inert gas arc welding,
Melting I! This impairs workability and the hot cracking resistance during welding, so in the end, for each of these eight elements, ri=
o, ox~0.16, A/-0,0G6~0.1
516. Mg=O, limited to 01-0.05%O range. Same complex Soka: ti? Regarding the total amount of ri+A/+Mg, 0.26 bags was set as the upper limit in consideration of hot cracking resistance during welding and deterioration of welding workability due to slag formation.

The above explanation has explained the minimum essential sl components in the present invention, but there are many techniques for welding core wires containing these components.
It was found that the addition of i, Mll, W, and Cr had a positive effect on the workability of f#I[1, and at the same time improved the strength of the welded joint IIc. Such an effect was remarkable in #&C when inert gas arc welding was carried out, but in the case of Si, when it exceeded 1.5, it had a negative impact on the hot cracking resistance during welding. When Mn exceeds 6, welding workability decreases, slag peelability decreases, and the bead tends to become convex. Furthermore, when W exceeds 5, the low temperature toughness and hot cracking resistance are significantly reduced. Also Cr is 4
If the width exceeds 68, the same problem as in the case of 4W may occur. Therefore, for the above four elements, 5i (1,5 superior), Mn (5
1, w < sl, Cr (4,81G), and there was no need to set a lower limit in particular.However, regarding w, cr, and si, we considered the joint performance from various viewpoints. W-2~4 I regret it.

(rzOJ * S s = 0.02 to 1.5% was determined as the preferred range. These things, 6. S i
, Mn*Cr5WFi.It was concluded that joint performance could be improved by blending one or more types. However, while these four elements have the effect of improving joint strength,
There is also the disadvantage that it promotes a decrease in low temperature toughness.

However, after various studies, it was found that low temperature toughness was significantly improved by the combined use of PE, and when the suitable blending range was determined, it was 2696 or less. That is, since it was revealed that if the strength exceeded 251G, the strength of the joint would be adversely affected, so 25G was set as the upper limit, but the preferable lower limit was 5.21G. The effect of adding 1 dye is 5i
, Mn, W, and CF are not added.

The above are the components and their blending ranges that are particularly defined in the present invention, but the applicable form of the welding core, the object to be welded, fl
The present invention also includes blending components other than those mentioned above in consideration of the combination with IKFi foots. Such components include Y, Hf, and Zr.

Examples include V, Ca, and rare earth elements (REM) II.

All of these are blended as deoxidizing metals.

It is not recommended to add too much as it will impair the hot cracking resistance during welding. The upper limit is 0.6 in the case of ■.

In the case of other elements, it is 0.1.

As described above, the present invention significantly improves the production yield due to its extremely good forgeability and rollability when provided as f# connection wire or coated arc welding rod core wire, etc. I was able to do that.

In addition, when used in actual #-welding, low-temperature toughness and high cracking resistance are improved, and l! Improved joint strength, improved welding workability,
Since excellent effects can be obtained, it is extremely useful as a weld core wire for low-temperature steels such as 9sNi steel.

Next, the present invention will be explained in detail.

An alloy having the composition shown in Table 1 is melted in a vacuum melting furnace,
After forging and hot rolling, II drawing is performed to obtain 4.0
Wires with wsφ and 1.2 tgφ were obtained. The former wire is a submerged arc welding wire and a coated arc welding rod core wire,
The latter wire was used for welding as a T1G welding wire. The flux used for submerged arc welding is 1 limestone: 251
Fluorite = 15 yen, Caligara: 101, alumina: 20 yen,
Sodium silicate was added to the powdered mixed raw materials consisting of rutile: 20 g, ice crystal, +E: 1 g, mixed, granulated and sintered at 460°C, and then granulated into 12 to 100 mesh. Using. 1 limestone: 80 for coated arc welding rod
Sorry, fluorite: 20To, alumina: 101 barium fluoride,
101! Sodium silicate was added to a powdered mixed raw material consisting of 10 flt of Ferron Recon, and kneaded, and this was mixed according to the above-mentioned 4. It was applied to the core wire of Otaxφ. The coating ratio was 8:1 for the core wire nibrax (weight ratio), and the coating was dried at 260°C.

Base material #i to be welded, 9 consisting of the component composition shown in Table 2
Ni steel (JIS G3127SL9N60:20
am)] to form a groove as shown in FIG.

The welding conditions in Table 2 are as shown in Table 3.
ZB512) evh, m welding table 1 shows $I
I4> Evaluation of the forgeability and rollability of the wire itself was described, but since Ti was added alone among A4FiTi, AI, and Mg, the decrease in forgeability and rollability due to MO addition was not covered. It has not yet been achieved. Also, A6 is Ti and AI
However, since the respective blending amounts of Ti and AI do not meet the respective lower limits required, it has not been possible to improve forgeability and rollability. Also, A8 is AZ and Mg
Although MO is added in a composite manner to satisfy the conditions of the present invention, the forgeability and rollability are not high because the blended amount of MO is excessive.

Table 1g4 lists the evaluations of joint strength, low-temperature toughness, hot cracking resistance, and welding workability, and A5 has poor hot cracking resistance because it contains a small amount of MO. Todoroki 6 has a high content of C, so it has poor low gj AUJ properties, 48 has a high content of MO, so it has poor low temperature toughness, and All has a high content of Cr, so it has poor low temperature toughness. , F. Since the blending amount is small, this drawback is not fully covered. J
In I&12, although the blending amounts of Mn and Cr exceed the specified upper limit, the low-temperature toughness is low because the blending amount of Fe is small.

A14 has a large amount of Fo, so? ! The negative effects of M-te-kei-ke-kei-kei were observed.

[Brief explanation of the drawing]

Figures 1 and 2 are graphs showing the relationship between the amounts of FiTi, Al, and Mg added and the number of high-temperature screws, and Figure 8 is an explanatory diagram showing the beveled cane of the base material. Compounding amount (%) Compounding amount (%) Figure 3 Procedural amendment (voluntary) August 81, 1980 Examiner of the Japan Patent Office 1, Case indication 1982 Hayabusa Patent No. 161218 Bow Showa No. 2 , The name of the invention is the name of the invention: Welded core wire for low temperature steel 3, Supplementary I: Relationship with 41 cases Patent Applicant A1
3-18 Wakihama-cho, Chuo-ku, Kobe City Name (119)
Kobe Steel Co., Ltd. Representative Kokichi Takahashi 4, Agent Postal code 530 Address 2-3-7 Dojima, Kita-ku, Osaka Shinko Building (1) "Scope of Patent Claims" will be corrected as shown in the attached document. Special W-F-Claims ・+11C, (o, 15-Year-Old (hereinafter referred to as cars) and M
In addition to O = 12 to 22, A''/=0.005 to 01
6th grade, Ti=0.01~0.1! '+%%Mg=0.0
Cfi 2 or more spears selected from 01 to 0.0596
, l + Ti + Mg), (L) &
ll! . f2+ C〈0.1.5%, MO=12-22% and F
e − (Including 25 chi, A/=, 0.005-0.16%. ri=0.01-0.15, Mg=0.001-00
2 or more selected from 5 regrets, CAl+ri, +Iu
lg) A bath sesshin for low-m which is patented as containing <0.25 yen within a satisfying range, and the remainder being N1 and more than 0.25 yen. =0.005~0.15 ratio, Ti=o, O1~0.15
Person in charge. , Δig=2 or more selected from 0.001 to 0.05, including (A/+Ti+Mg)(0.25%), and further contains Mn(5%, W(596, Cr≦
A weld core wire for low temperature steel, characterized in that it contains one or more selected from 4.81 and 5i≦14-, with the remainder being Ni and unavoidable impurities. +41c (0,1fi-IMO!131~22 饅 and F・(251 included, AI=0.005~0.1 a
Is. Ti=0.01~0.15%, Mg=0.001~0.
05-, two or more selected from (A/+Ti+Mg
) 40.35 excellent within a satisfactory range, I! 1lQ1n
451G, W, (51Cr, <4.8 arrogant and 5i41.
A # centcentric ring for low-temperature steel, characterized in that it contains one or more selected from five types, with the remainder consisting of Ni and unavoidable impurities.

Claims (1)

[Claims] +11c<0.15 weight qb (hereinafter simply referred to as "excellent") and MO=
In addition to 12-22 regrets, A/=0.005-0,15 regrets4i=o, o1-0.15 regrets, Mg=0.0O]~0,
Contains two or more selected from 05111 within a range that satisfies (AZ + Ti + Mg) <0.251, and the remainder is Ni
and unavoidable impurities. 1!1c40.15 1Mo=12~221G and F6
<Including 2jS1g, A/=0.005 to 0.15
91G. Ti=0.01-0.151. Mg-0,001~0.
05-, two or more selected from (A/+Ti+Mg
)〈01!5 (a welding cord for low-temperature steel characterized by containing i within a satisfying range, and the remainder being Ni and unavoidable impurities. +211C (0,1516 and Mo = 12 to 22 ( AI
=o, ooa~0.16, Ti=0.01~0.16
I regret it. [g=Q, Q 01~0.051dk including 62 or more selected monkey species within the range that satisfies (A/+Ti+Mg)〈0.25, further &CMn〈5m, w〈s, Cr(4
, 816 and 5t (containing one or more selected from t, a*, the remainder being Ni and unavoidable impurities). 141G40.16%, Mo=1ft~22% and Fe
In addition to d251G, A/-0,005 to 0.15,
TixQ, Ql~0.15 coefficient, Mg=0.001~0,
Two or more types selected from Section 05, (A/+Ti+Mg
A weld core wire for low-temperature steel, characterized in that it contains one or more selected from the following, and the remainder consists of Ni and unavoidable impurities.