TW200932412A - Solid welding wire for carbon dioxide gas welding - Google Patents

Abstract

The present invention provide a solid welding wire for carbon dioxide gas welding, comprising C: 0.03-0.10 mass%, Si: 0.67-1.00 mass%, Mn: 1.81-2.50 mass%, S: 0.006-0.018 mass%, Ti: 0.100-0.150 mass%, B: 0.0015-0.0070 mass%, and Cu: 0.10-0.45 mass% including plating ingredient, wherein the parameters PBS and PMT as expressed in the following formulas satisfy the conditions: PBS ≤ 10 and PMT ≤ 32, and it is specified that P is less than 0.020 mass%, Nb is less than 0.04 mass%, V is less than 0.04 mass%, Al is less than 0.04 mass%, and the remaining is Fe and inevitable impurities. PBS=[B]x[S]x10<5>, and PMT=[Mn]x[Ti]x10<2>. Based on this composition, adequate weld penetration can be obtained even applied to narrow slot, so as to obtain weld metal with excellent mechanical properties including strength and toughness.

Description

200932412 IX. INSTRUCTIONS OF THE INVENTION [Technical Fields of the Invention] The present invention relates to a solid electrode for carbon dioxide gas welding used for carbon steel gas shielded arc welding of mild steel or 490 to 5 20 N/mm2 high-tensile steel. The welding is performed with high efficiency, and a solid electrode for arc welding of the carbon dioxide gas of the welded metal having good mechanical properties can be obtained. ❹ [Prior Art] Recently, in the field of building reinforcement, the gas shielded arc fusion method using co2 as a shielding gas is mainly used because of its high efficiency. In the past, the gas-shielding arc welding method almost always uses an artificial semi-automatic welding method. However, in order to save manpower and reduce costs, and to further improve the welding efficiency by utilizing nighttime or holiday unmanned operation, automatic welding using robots has also begun to spread. On the other hand, in terms of welding quality, the improvement of the shock resistance is focused on, and in order to improve the performance of the welded joint portion, in the 1997 JASS6 revision and the 1999 Building Standard Law revision, the heating and inter-layer heating during welding are performed. Temperature is capped. Affected by this trend, welding rods corresponding to high heating and high-rise temperatures have been developed for welded electrodes, which allow up to 40kJ/cm of maximum heating and 3 50°C of interlayer temperature for 490N/mm2 grade carbon steel sheets. 5 20N/mm2 grade carbon steel plate allows up to 30kJ/cm of maximum heating and 250°C between layers, and JIS in 999N/mm2 = YGW18 in 1999. Up to now, it has been able to obtain better mechanical properties than conventional welding rods at high heating and high-rise temperatures. -4- 200932412 The 540N/mm2 grade electrode has been rapidly popularized. In addition, the grade electrode has been popularized at a low level for heat supply and interlayer temperature. In recent years, the number of fully self-welding 540N/mm2 electrodes in the robot has begun to increase. In the electrode corresponding to the temperature between the carbon dioxide gas shielding and welding, the content of Si, Mn, and Ti is more than that of the conventional electrode as a whole, and eu, Al, Nb, V, Ni, and the like are added as needed. In this way, the hardenability of the steel is improved, and the toughness due to the grain refinement is increased, and the precipitation hardening action is added to increase the strength. However, the actual situation of these conventional electrodes is that they do not take into account the welding applied to the robot. Conventional and high-temperature electrodes have the disadvantage of excessive slag generation. Since the slag is insulative, the accumulated slag is likely to be a defect such as insufficient penetration and slag contamination. In addition, as long as the unnatural peeling of the slag occurs slightly, even if the arcing position is changed and the re-arcing is attempted, the error will still be wrong. Therefore, the welding robot will judge the error and stop the maximum strength of the person to save the manpower, but the arc is caused in a short time. In the case of destabilization, it is necessary to frequently enter the industry manually, or to start the arcing part in order to repair the arcing error, so that the advantages cannot be exerted. Therefore, in order to solve the problem of proposing a welding electrode, it is necessary to have a large current, a high-rise, etc. in the 540N/mm2 automatic fusion in the 490N/mm2 automatic melting under the conditions of maximum heating of 40 kJ/cm and 350 °C. The deoxidizing component ports Mo, B, and Cr, and the combination of solid solution hardening, all of which correspond to large currents at the time of design and poor peelability hinder the direct generation of arc stabilization, and the welding robot continues to occur in the arcing industry. The welding machine slag is deposited to remove the slag from the slag removal. This problem is expected to have the highest interlaminar temperature mechanical properties, 200932412, and the amount of slag generated is small, the peelability is also good, and the continuous stacking height is high and the efficiency is high. In response to this expectation, as the electrode which can improve the slag removability, the electrode described in Japanese Laid-Open Patent Publication No. 2006-8 8 1 87, JP-A-2006-305605, and JP-A No. 2006-15045. Further, an electrode which is improved not only in the slag removability but also in the amount of slag formation is disclosed in Japanese Laid-Open Patent Publication No. 2004-122170, No. 2006-2 6 64. ❹ [Summary] However, recent robotic fusion technology has undergone significant evolution. Therefore, narrow groove formation with a groove angle of 30° has been achieved. That is to say, the conventional groove angle is 35°, but in order to reduce the groove area to reduce the number of layers and shorten the welding time, reduce the amount of welding electrode used, reduce the thermal strain, and increase the strength to reduce the interlayer temperature. The mechanical properties of the welded metal such as toughness have been able to achieve a narrow groove of about 30° for this purpose. In this way, the angle of the groove becomes small. Since the torch tip easily interferes with the grooved surface, the distance from the front end of the torch to the bottom surface of the groove is inevitable. The so-called electrode protrusion length is often lengthened, and it is easy to cause weld penetration due to the reduction of the arc force. bad. In addition, since the protruding length is long, the gas shielding property is deteriorated, and nitrogen tends to be mixed into the molten metal from the atmosphere, and the toughness tends to decrease. Conventionally, there has been no development of a technique for preventing fusion penetration failure in terms of a welded electrode. Further, there is no welding electrode which can achieve the excellent mechanical properties such as excellent slag removability and slag amount, and excellent mechanical properties such as strength and toughness. Therefore, it is expected to develop an optimum welding electrode that can prevent the welding of -6-200932412 people in the groove type of 50%, which is poor in permeability, has excellent mechanical properties, and can correspond to narrow-grooving construction using a machine for multi-layer welding. . The present invention has been developed in view of the above problems, and an object of the present invention is to provide a solid electrode for carbon dioxide gas welding, which can obtain sufficient weld penetration even in a narrow-opening operation, and can provide excellent mechanical properties such as strength and toughness. Welding metal. The solid electrode for carbon dioxide gas welding of the present invention contains C 0.03 to 0.10% by mass, Si: 0.67 to 1.00% by mass, Μη: 1.81 to 2. mass%, S: 0.006 to 0_018% by mass, Ti: 0.100 to 0.150 mass, B: 0.0015 to 0.0070% by mass, including Cu 〇·10 to 0.45% by mass of the plating component, and the balance is Fe and unavoidable impurities. The parameters PBS and ΡΜτ represented by the following 1 and 2 are in accordance with PBSS10, Ρμτ$32 Further, P: 0.020 mass% or less, Nb: 0.04 mass% or less, V 〇. 04 mass% or less, and A1: 0 · 04 mass% or less. 〔Formula 1〕

Pbs=[B]x[S]x105 [Equation 2] Ρμτ = [Μη] X [Ti] X 1 02 Here, [] represents the content (% by mass) of the element in the electrode. In the solid electrode for welding carbon dioxide gas, at least one selected from the group consisting of Mo: 0.25 mass% or less, Cr: 0.25 mass% or less, and Ni 0.25 mass% or less is preferable. Further, it is preferable that m10S2 of 〇.〇1 to i.〇〇g exists on the surface of the electrode every 10 kg of the electrode. [Invention] The inventors of the present invention conducted an investigation into the relationship between the length of the electrode projection, the transition pattern of the droplet, and the penetration depth of the weld. As a result, the following matters were clarified. When the feed amount of the welding rod is constant, if the protruding length becomes long, the electric resistance from the tip end of the welding rod to the energization point in the chip rises, and the melting is easily caused by the temperature rise, so the welding current supplied from the fusion splicer is lowered. , but the welding voltage rises. Under the condition that the welding current is reduced and the welding voltage is increased, since the © arc reaction force is small and the traveling space (arc length) is long, the droplets which are melted at the front end of the electrode and fall to the welded portion are likely to become large spherical droplet transfer. The directivity of the arc is weakened, and the area of the concentric drop-shaped drop region centered on the electrode is enlarged. Further, the transition period is also lengthened, the arc force applied to the base material is weak, and the penetration depth of the fusion is small. In order to avoid this phenomenon, it is most effective to prevent the complete migration of the spherical droplets. Therefore, the inventors have found that it is necessary to suppress the factor which causes the droplets to grow substantially. The largest influence on the size of the droplets is Ti. The less the Ti content in the electrode, the more the droplet growth can be suppressed, and the short-circuit transition, the concentration of the arc increases, the area of the droplet drop area shrinks, and the penetration depth of the weld increases. . In Fig. 1, the horizontal axis represents the length of the electrode protrusion (mm), and the vertical axis represents the penetration depth (mm) of the weld, and represents the relationship between the Ti content, the length of the electrode protrusion, and the penetration depth of the weld. Among them, the feed amount of the electrode is l〇m/min. As shown in Fig. 1, the longer the protruding length of the welding rod, the smaller the penetration depth of the welding, but the smaller the Ti content, the smaller the penetration depth of the welding. Further, the oxide of Ti is a source of slag, and the amount of Ti is made smaller than in the related art, and problems caused by slag deposition can be alleviated. -8 - 200932412 On the other hand, Ti has a strong affinity with nitrogen, and combines with nitrogen in the case of poor shielding to prevent the occurrence of pores and has an effect of preventing metal embrittlement. Reducing Ti causes problems of pore formation and metal embrittlement. Therefore, in order to reduce the penetration depth of the weld caused by Ti and the problem of pore formation and metal embrittlement, the contents of Μη and B are optimized. . In the following, the reason for the component addition and the reason for the composition limitation of the solid electrode for carbon dioxide gas welding of the present invention will be described. Q "C : 0.0 3 ~ 0 · 1 0 mass % " C is an important additive element for ensuring strength, but when it is less than 0.03 mass%, it is not required to ensure high heat supply and high-temperature temperature welding. strength. Therefore, C is 0.03% by mass or more, preferably 0.05% by mass or more. On the other hand, if C is excessively added, a high temperature crack is likely to occur. Further, if C is excessively added, in the arc atmosphere, the CO explosion image also causes an increase in the amount of spatter generated, which deteriorates the arc stability. Further, if the C content is large, the strength of the welded metal is too large, and the toughness is lowered by ©. When the C content exceeds 0.10% by mass, these effects become remarkable, so the upper limit is made 0.10% by mass. "Si: 0 · 6 7 ~ 1 0 0 quality 0 / 〇,,

Si is mainly added to ensure strength and prevent porosity defects caused by deoxidation. Further, although the addition of Si increases the amount of slag, the slag releasability is improved. These effects are effective when the Si content is 0.67 mass% or more. When the Si content is less than 0.67 mass%, the slag removability is poor and the arc becomes unstable. The lower limit 更 of Si is more preferably 0.75 mass%. On the other hand, when Si is excessively added and exceeds 1.00% by mass, the amount of slag is excessively increased at 200932412, the arc stability is deteriorated, and the toughness 値 is lowered. Therefore, the upper limit Si of Si is 1.0% by mass. "Mn: 1.8 to 2.50 mass%" Μη has a deoxidizing effect of the weld metal, and the strength of the weld metal is increased, and the effect of obtaining a weld metal having high toughness is obtained. In a robot system with a narrow slot-corresponding function, the maximum electrode projection length is set to be long, and the occurrence of porosity and toughness due to shielding failure are likely to occur. Therefore, more Μ is added as a robot electrode to prevent these disadvantages. Therefore, the Μη content must be added at least 1.81% by mass or more. On the other hand, when the Μη content exceeds 0.25 mass%, the amount of slag increases, and the slag releasability is lowered, and as a result, the arc stability is also deteriorated. Further, as will be described later, the upper limit Μ of Μη must be suppressed to be lower depending on the relationship with the amount of Ti. “S : 0 · 0 0 6 ～ 0 · 0 1 8 Mass 0/〇” By adding S, the surface tension of the molten pool is lowered, the physical unevenness at the time of solidification is reduced, and the surface of the welded metal is smoothed. Effect.借此 By this, the slag releasability can be improved. When s is less than 0.006 mass%, the effect is not exhibited, and the arc stability is deteriorated due to poor peelability. On the other hand, even if the addition of s exceeds 0.018 mass%, not only the surface shape improving effect of the welded metal is saturated, but also high temperature cracking is likely to occur. Further, the form of the slag is granulated, the arc is prevented from being melted, and local arc instability is caused, and the toughness is also lowered. Therefore, the upper limit of S is 〇. 〇 18% by mass. Further, as will be described later, the upper limit of S is not required to be suppressed to be lower depending on the relationship with the amount of enthalpy. “T i : 0 _ 1 0 0 ~ 0 . 1 5 0 mass % ” -10- 200932412 Τι has an effect of improving arc stability in a high current range. In general, there are many welding rods in which Ti is added at about 0.20 mass%. One of the characteristics of the composition of the electrode of the present invention is that the Ti content is lower than that of a general electrode. When Ti is less than ι.ιοο% by mass, the arc stability is poor and the amount of spatter generated is increased. Therefore, T i must be added with 〇 丨〇 〇 mass % or more. On the other hand, if the Ti content is increased, the melt penetration depth is reduced due to the change in the above-described droplet transfer mode, and the weld enthalpy penetration is likely to occur when the electrode has a long projection length. When the Ti content exceeds 0.150% by mass, the completely spherical droplet transfer is caused, and the fusion penetration failure occurs, so the upper limit is made 0.150% by mass. As will be described later, the upper limit of the Ti content is not required to be suppressed to be lower depending on the relationship with the Μη content. In the case where the robot is welded, since the optimum voltage and the welding speed can be always set, the arc stability does not deteriorate even if the Ti content is low. "B: 0.001 5 to 0.0070% by mass" By adding a small amount of B, the crystal grains of the fused gold ruthenium can be made fine, and thus the effect of improving strength and toughness is enhanced. When the B content is less than 0.0015% by mass, the effect of improving the strength and toughness of the welded metal cannot be exhibited, and these mechanical properties are insufficient. Therefore, B is 0.0015 mass% as the lower limit. On the other hand, when B is excessively added and exceeds 0.0070% by mass, high temperature cracking is likely to occur. Therefore, the B content is 〇.0070% by mass as the upper limit 値 . Further, the upper limit of the 'B content' is not required to be suppressed to be lower depending on the relationship with the amount of S. "Cu : 0.1 〇~0.45 mass %"

When Cu is excessively added, it is easy to cause high-temperature cracks to occur, and the properties of slag-11 - 200932412 are changed to deteriorate the peeling property. As a result, the arc stability is deteriorated. It is not necessary to actively add Cu to the electrode wire, and in most cases, it is to improve conductivity, rust resistance, linearity, and aesthetics, and it is added in the state of Cu component in copper plating performed on the surface of the electrode. . When Cu is converted to a plating amount of 0.10% by mass or less, the film thickness of the plating film is too small, resulting in poor conductivity, arc instability, and spatter. On the other hand, when the Cu content exceeds 0.45 mass%, the high temperature crack and the slag peelability become a problem of 0, so the upper limit of Cu is 0.45 mass%. Further, Cu is a combination of the amount contained in the wire and the copper plating component. ** PBs ^ 10 (Pbs = [B]x[S]x105)" Both B and S are elements that cause high temperature cracks. In addition to separately specifying the B and S content, the two elements must be interconnected. Restrictions are made to prevent high temperature cracks. That is, since high temperature cracks are likely to occur in the welding of narrow slots, it is necessary to pay more attention to the prevention of cracks than before, in addition to separately specifying the contents of B and S, respectively. The two elements are restricted by mutual correlation. In Fig. 2, the horizontal axis represents the S content, and the vertical axis represents the B content, which indicates the relationship between the occurrence of cracks and the content of S and B. As shown in Fig. 2, As a result of experimental investigations by the inventors, it has been found that in the range of PBS &gt; 10, even if both B and S are within the prescribed range of the present invention, cracks occur because both elements are in a high content range. The relevant parameter Pbs is defined as Pbs = [B]x[S]x105 ([B], [S] respectively represent B content (% by mass), S content (% by mass) in the electrode), and the pBS must be 1〇 The following. -12- 200932412 “PMTS 32 (PMT = [Mn]x[Ti]xl02)” Μη and Ti are melting The main generating elements of the slag, in addition to separately specifying the contents of Μη and Ti, must also limit the two elements in a cross-correlation manner to prevent excessive slag from occurring. In Fig. 3, the horizontal axis represents the Μη content, vertical The axis is the Ti content, and indicates the relationship between the slag content and the like and the content of Μ and Ti. The inventors have found that, as shown in Fig. 3, in the range of PMT &gt; 32, even Μη and Ti are © in the present invention. In the predetermined range, since the content of both elements is high, the amount of slag formed is large, and the slag removability is also deteriorated, so the stability of the arc is poor. In addition, if the amount of slag is increased, slag must be frequently performed. Removal, the operation efficiency is reduced. Therefore, when the relevant parameter PMT is defined as PMT=[Mn]x [Ti]xl02, ([Mn], [Ti] respectively represent the Μη content (% by mass) and the Ti content (quality) in the electrode %)), the ΡΜΤ must be 32 or less. “ Ρ : 0.0 2 0% by mass or less Ρ Ρ is one of the main elements that cause high temperature cracks to occur, and there is no need to actively add ρ. Therefore, it will not be a high temperature crack. The upper limit of the problem, the upper limit of the plan Set to 0.020 mass%. "Nb: 0.04 mass% or less, V: 0.04 mass% or less, Α1: 0.04 mass% or less"

Nb, V, and A1 reduce the toughness of the weld metal under low heat welding conditions. Therefore, it is necessary to avoid the positive addition of these elements as the upper limit of the allowable range in which the toughness can be neglected, and the upper limit 値 of these elements is set to 0. 〇 4% by mass. “Mo : 0.25 mass% or less, Cr: 0.25 mass% or less, Ni: -13- 200932412 0.2 5 mass% ”

Mo, Cr, and Ni increase the hardenability of the weld metal and increase the strength, and it is preferable to add it positively. Mo, Cr, and Ni maintain moderate strength even at higher heating and interlayer temperatures. The addition of these elements does not require a lower limit, but as long as at least one of Mo, Cr, and Ni is added at 0.05 '% by mass or more, the effect is remarkable. On the other hand, if the addition amount of these elements exceeds 0.25 mass%, the microstructure of the welded metal may cause turbidity and ironiness to cause a decrease in toughness. Therefore, these elements are each set to be 0.25 mass% or less at the time of addition. "MoS2 on the surface of the electrode: 每_〇1~l.OOg per 10kg of electrode" The feedability of the electrode has a great influence on the slag removability. Stable feed of the electrode will stabilize the formation of the molten pool, the thickness of the generated slag will be uniform, and the strain of heat shrinkage will uniformly function, thereby facilitating the overall peeling. M〇S2 on the surface of the electrode will reduce the fusion of the feed point between the tip and the electrode, which will help improve the feedability of the electrode. In the conventional method for improving the feedability of the electrode, there is a method of excessively oxidizing along the grain boundary of the surface of the electrode, and in this method, the amount of slag is increased due to excessive amount of ruthenium. On the other hand, since the application of M〇S2 does not increase the amount of slag compared with other methods of improving the feedability, it is suitable to improve the electrode feedability of the electrode of the present invention. This effect is effective in attaching MoS2 of more than O.Olg per 10 kg of the electrode. On the other hand, if MoS2 adheres to more than l_〇〇g per 10kg of welding rod, it will start to form in the feed system. 'The blockage of Mo S2 will cause the feed failure to occur, which will affect the slag property and cause the stripping. Reduced sex. As a result, the arc stability is deteriorated. Therefore, it is preferable that 'there is -14 to 200932412 0.01 to 1.00 g of m 〇 s 2 ° per 10 kg of the electrode. [Examples] Hereinafter, in order to explain the effects of the present invention, the implementation of the scope of the present invention is included. The electrode of the example and the electrode of the comparative example which deviated from the scope of the present invention are the results of the welding test. Figs. 4(a) to 4(C) are views showing the shape of the welded test piece and the shape of the groove. Fig. 4(a) is a cross-sectional view showing the grooving portion in an enlarged manner, Fig. 4(b) is a front view of the test body, and Fig. 4(C) is a side view. The diaphragms 1 are vertically arranged, the shafts of the circular steel tubes 3 are horizontally disposed, and the end faces of the circular steel tubes 3 are opposed to the separators 1. The end face of the circular steel pipe 3 is chamfered to form a grooved groove with the separator 1. Further, a cylindrical spacer 2 is placed on the inner surface of the circular steel pipe 3. Then, the grooved portion is subjected to circumferential seam welding by the welding torch 4. Table 1 below shows the welding conditions. Further, Table 2 below shows combinations of the steel sheets of the separator 1, the steel pipe 3, and the gasket 2, and Table 3 shows the composition (% by mass) of the separator 1, the steel pipe ® 3, and the gasket 2. With the welding conditions shown in Table 1, the welded test body shown in Fig. 4 was welded by a commercially available robotic robot welding system. Further, the separator 1 and the steel pipe 3 are blast furnace materials, and the gasket 2 is a commercially available electric furnace material, and the gasket 2 has a very high nitrogen content and poor weldability. The groove angle is generally 35°, and the root gap is 7 mm. However, in the welding test, a narrow groove construction with a groove angle of 30° and a root gap of 5 mm was performed. Then, the peeling property of the slag after the completion of the welding was calculated by digital image processing, and the amount of slag was measured. The strength and toughness of the welded metal were measured by a tensile test and a Charpy impact test. In addition, the stability of the arc and the amount of spatter generated in the fusion -15-200932412 were also recorded. In addition, ultrasonic flaw detection tests were conducted to investigate whether weld penetration and high temperature cracks occurred. Table 4 below shows the composition (% by mass) of the electrodes of the examples and the comparative examples. Further, Table 5 below shows the test results of the welding test. Further, in the composition of Table 4, "&lt;〇.***" is shown, and the analysis result of the composition is a 値 which does not reach the lower limit of the general analysis accuracy, and is not industrially contained. The evaluation methods of the respective characteristics shown in Table 5 are as follows. Regarding the melting Q slag peeling evaluation method, the evaluation of the peeling property and the slag amount was carried out only under the condition 1 (see Table 2) in which the thickness of the steel pipe was thin. Further, it was confirmed that the welded electrode having good slag removability under Condition 1 was also good under Condition 2. At the point where the welding start point is welded to the final layer, a photograph is taken at a position of 1 mm before and after the electrode is returned to the front side of the electrode, that is, a total of 200 mm (see Figures 4(b) and (c)). . Next, the appearance of the bead is dilated into (a) a portion where the slag is naturally peeled off and (b) a portion where the slag adheres, and the distribution thereof is determined. The image analysis software calculates the measurement of each pixel separately, and the slag peeling rate (%) is obtained by (a) / ((a) + (b)) xl00. The slag peeling rate was 15% or more, and it was judged that the slag removability was good. Next, regarding the amount of slag, all of the slag was recovered (including the natural peeling after photographing of the outer surface of the bead), and the weight was measured. When the amount of the slag was 12 g or less, it was judged that the amount of slag was good. The tensile test and the Charpy impact test of the welded metal were carried out under the condition 2 (refer to Table 2), and the A2 No. (parallel diameter 6 mm) of JIS Z 3111 was taken from the positions shown in Figs. 5 and 6 respectively. Standard test pieces (l〇mm square) are available for testing. Also, the tensile test was carried out at room temperature of 20 °C in the Charpy Chong-16-200932412 test, which was 〇°C, and the three averages were used as the evaluation 値. The tensile strength is 4 90 N/mm 2 or more, and the Charpy impact test is 70 J or more on average. The arc stability was judged to be good according to the sensory evaluation in the welding, and the slag did not interfere with the occurrence of the arc. Also, the situation in which the arc is unstable due to poor electrode feeding is also unacceptable. The spatter generation amount is after the welding of Condition 1 (refer to Table 2) is completed, and the spatter attached to the shield nozzle is collected and the weight is measured. It was judged that the amount of spatter generated was 6 g or less. [Table 1] Welding machine type welding robot welding power supply, polar DC machine 'reverse polarity shielding gas C 〇 2, flow rate 25 liters / minute electrode diameter 1.2mm Heating maximum 40kJ / cm Inter-layer temperature maximum 350 ° C posture downward welding rod protruding Length 27 to 35mm Slag removal condition 1: None, Condition 2: Spatter removal and cleaning conditions with tip attachment 1 : None, Condition 2: Yes [Table 2] Partition steel pipe gasket condition 1 (thin plate) SN490C plate Thick 25mmx450mm square STKN490B wall thickness 16mmx outer diameter 350mm SN490A wall thickness 9mmx outer diameter 334mm condition 2 (thick plate) SN490C plate thickness 75mmx800mm square STKN490B wall thickness 60mmx outer diameter 700mm SN490A wall thickness 9mmx eve f diameter 640mm -17- 200932412

[Table 3] Use / Steel type C Si Μ Ρ s N Separator / SN490C 0.15 0.35 1.45 0.010 0.003 0.0029 Steel pipe / STKN490B 0.09 0.12 1.02 0.010 0.003 0.0035 Liner / SN490A 0.11 0.13 0.46 0.017 0.022 0.0125 [Table 4-1] Welding rod chemistry Composition (% by mass) No C Si Μη Ti SP Cu B Pbs Pmt 1 0.06 0.80 1.85 0.15 0.009 0.011 0.20 0.0030 2.7 27.8 2 0.09 0.90 2.00 0.14 0.010 0.012 0.23 0.0020 2.0 28.0 3 0.04 0.95 2.35 0.12 0.008 0.010 0.27 0.0054 4.3 28.2 4 0.05 0.75 1.89 0.15 0.006 0.009 0.25 0.0045 2.7 28.4 Real 5 0.07 0.70 2.45 0.13 0.008 0.015 0.17 0.0040 3.2 31.9 Application 6 0.03 0.88 1.95 0.15 0.012 0.007 0.30 0.0060 7.2 29.3 Example 7 0.10 0.85 1.84 0.14 0.018 0.013 0.21 0.0055 9.9 25.8 δ 0.06 0.67 1.90 0.15 0.007 0.008 0.15 0.0070 4.9 28.5 9 0.05 1.00 1.85 0.11 0.008 0.005 0.45 0.0040 3.2 20.4 10 0.07 0.90 1.81 0.15 0.008 0.010 0.20 0.0035 2.8 27.2 11 0.06 0.75 1.88 0.10 0.016 0.010 0.28 0.0050 8.0 18.8 12 0.07 0.90 1.90 0.14 0.010 0.012 0.10 0.0025 2.5 26.6 13 0.06 0.80 2.10 0.14 0.009 0.0 11 0.20 0.0015 1.4 29.4 14 0.06 0.69 1.82 0.13 0.010 0.008 0.40 0.0046 4.6 23.7 15 0.08 0.90 1.90 0.11 0.011 0.011 0.25 0.0018 2.0 20.9 16 0.05 0.82 1.87 0.13 0.007 0.012 0.17 0.0040 2.8 24.3 17 0.05 0.85 1.97 0.14 0.006 0.007 0.25 0.0035 2.1 27.6 18 0.06 0.80 2.20 0.14 0.010 0.020 0.20 0.0044 4.4 30.8 -18- 200932412

[Table 4-2]

No electrode chemical composition (% by mass) M〇S2 g/electrode l〇Kg Nb V A1 Mo Cr Ni Example 1 &lt;0.005 &lt;0.005 &lt; 0.005 &lt; 0.005 0.010 &lt; 0.005 &lt; 0.01 2 &lt; 0.005 &lt;; 0.005 &lt; 0.005 0.20 &lt; 0.005 &lt; 0.005 0.20 3 &lt; 0.005 &lt; 0.005 &lt; 0.005 0.02 &lt; 0.005 &lt; 0.005 &lt; 0.01 4 &lt; 0.005 &lt; 0.005 &lt; 0.005 0.15 0.010 &lt; 0.005 &lt; 0.01 5 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.01 6 &lt; 0.005 &lt; 0.005 &lt; 0.005 0.22 0.060 &lt; 0.005 0.18 7 &lt; 0.005 &lt; 0.005 &lt; 0.005 0.06 0.020 &lt;0.005 0.54 8 0.04 &lt; 0.005 &lt; 0.005 0.13 0.010 &lt; 0.005 &lt; 0.01 9 &lt; 0.005 &lt; 0.005 &lt; 0.005 0.01 0.23 &lt; 0.005 &lt; 0.01 10 &lt; 0.005 0.04 0.011 0.25 &lt; 0.005 0.10 0.29 11 0.050 &lt; 0.005 &lt; 0.005 0.03 0.200 0.25 &lt; 0.01 12 &lt; 0.005 0.050 &lt; 0.005 &lt; 0.005 &lt; 0.005 0.020 0.77 13 0.009 &lt; 0.005 0.04 &lt; 0.005 0.030 0.050 0.98 14 &lt; 0.005 &lt; 0.005 &lt;0.005 0.15 &lt;0.005 0.010 &lt;0.01 15 &lt;0.005 &lt;0.005 &lt;0.005 &lt;0.005 0.010 &lt;0.005 &Lt; 0.01 16 &lt; 0.005 &lt; 0.005 &lt; 0.005 0.10 &lt; 0.005 &lt; 0.005 0.03 17 0.01 &lt; 0.005 &lt; 0.005 &lt; 0.005 0.030 &lt; 0.005 &lt; 0.01 18 &lt; 0.005 0.01 0.02 0.20 0.15 0.15 0.30 - 19- 200932412

[Table 4-3] No. C Si Μη Ti SP Cu B Pbs Pmt Comparative Example 19 0.02 0.75 1.85 0.13 0.008 0.006 0.25 0.0040 3.2 24.1 20 0.11 0.92 2.30 0.13 0.008 0.010 0.19 0.0030 2.4 29.9 21 0.05 0.66 1.85 0.15 0.010 0.015 0.25 0.0020 2.0 27.8 22 0.08 1.02 2.10 0.14 0.015 0.011 0.28 0.0050 7.5 29.4 23 0.09 0.82 1.80 0.12 0.010 0.016 0.18 0.0035 3.5 21.6 24 0.08 0.75 2.52 0.11 0.009 0.010 0.20 0.0044 4.0 27.7 25 0.04 0.80 1.99 0.09 0.014 0.008 0.15 0.0040 5.6 17.9 26 0.06 0.85 1.82 0.16 0.011 0.007 0.29 0.0045 5.0 29.1 27 0.07 0.95 2.00 0.17 0.013 0.012 0.21 0.0018 2.3 34.0 28 0.06 0.80 2.30 0.14 0.009 0.009 0.20 0.0048 4.3 32.2 29 0.08 0.81 1.90 0.12 0.005 0.007 0.22 0.0025 1.3 22.8 30 0.03 0.90 1.98 0.14 0.019 0.016 0.23 0.0030 5.7 27.7 31 0.06 0.86 1.87 0.13 0.016 0.013 0.30 0.0064 10.2 24.3 32 0.07 0.90 1.82 0.15 0.009 0.021 0.25 0.0016 1.4 27.3 33 0.05 0.83 2.05 0.14 0.008 0.005 0.08 0.0026 2.1 28.7 34 0.05 0.77 1.87 0.14 0.013 0.009 0.47 0.0063 8.2 26.2 35 0.06 0.88 1.87 0.15 0 .009 0.015 0.40 0.0013 1.2 28.1 36 0.10 0.69 1.95 0.14 0.012 0.011 0.20 0.0072 8.6 27.3 37 0.03 0.80 2.40 0.15 0.018 0.008 0.26 0.0058 10.4 36.0 38 0.04 0.70 1.87 0.12 0.015 0.012 0.19 0.0030 4.5 22.4 39 0.08 0.81 1.84 0.15 0.006 0.010 0.15 0.0041 2.5 27.6 40 0.07 0.88 1.95 0.14 0.007 0.006 0.26 0.0055 3.9 27.3 41 0.09 0.90 1.83 0.13 0.009 0.008 0.19 0.0045 4.1 23.8 42 0.07 0.86 1.85 0.15 0.009 0.013 0.26 0.0039 3.5 27.8 43 0.08 0.77 1.99 0.12 0.009 0.010 0.20 0.0025 2.3 23.9 44 0.06 0.89 1.90 0.14 0.011 0.010 0.18 0.0066 7.3 26.6 45 0.07 0.90 1.95 0.23 0.003 0.012 0.25 &lt;0.0001 0.0 44.9 46 0.08 0.79 1.72 0.19 0.005 0.019 0.17 0.0043 2.2 32.7 47 0.11 0.80 1.45 &lt;0.01 0.012 0.010 0.25 0.0001 0.1 0.0 48 0.06 0.50 2.00 0.18 0.004 0.012 0.20 0.0019 0.8 36.0 49 0.07 1.10 1.82 0.05 0.025 0.006 0.20 &lt;0.0001 0.0 9.1 50 0.06 0.25 1.95 0.15 0.015 0.010 0.25 0.0101 15.2 29.3 -20- 200932412 [Table 4-4] No Nb V A1 Mo Cr Ni M〇S2 19 &lt ;0.005 &lt;0.005 &lt;0.005 0.15 &lt;; 0.005 &lt; 0.005 0.05 20 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.01 21 &lt; 0.005 &lt; 0.005 &lt; 0.005 0.22 &lt; 0.005 &lt; 0.005 0.15 22 &lt; 0.005 &lt;0.005 &lt; 0.005 0.16 &lt; 0.005 &lt; 0.005 0.25 23 &lt; 0.005 &lt; 0.005 &lt; 0.005 0.13 0.005 &lt; 0.005 0.50 24 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 0.78 &lt;0.005 &lt;0.005 &lt;; 0.005 &lt; 0.005 0.90 28 &lt; 0.005 &lt; 0.005 &lt; 0.005 0.13 &lt; 0.005 0.020 &lt; 0.01 29 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 0.010 0.10 30 &lt; 0.005 &lt; 0.005 &lt;; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.01 31 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.01 32 &lt; 0.005 &lt; 0.005 &lt; 0.005 0.10 &lt; 0.005 &lt;0.005 &lt;0.01 33 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.01 ratio 34 0.080 &lt; 0. 005 0.010 0.005 &lt;0.005 &lt;0.005 &lt;0.01 is 35 &lt;0.005 &lt;0.005 &lt;0.005 &lt;0.005 &lt;0.005 &lt;0.005 &lt;0.01 Example 36 &lt;0.005 &lt;0.005 &lt;0.005 &lt;0.005 &lt;; 0.005 &lt; 0.005 0.50 37 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 0.65 38 0.050 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 39 0.010 0.050 &lt; 0.005 0.060 &lt; 0.005 &lt; 0.005 0.15 40 &lt; 0.005 &lt; 0.005 0.050 &lt; 0.005 0.150 &lt; 0.005 0.11 41 &lt; 0.005 &lt; 0.005 &lt; 0.005 0.27 &lt; 0.005 &lt; 0.005 &lt; 0.01 42 &lt; 0.005 &lt; 0.005 &lt;0.005 0.010 0.28 &lt;0.005 &lt;0.01 43 0.010 &lt;0.005 0.010 &lt;0.005 0.020 0.27 0.05 44 &lt; 0.005 0.006 &lt; 0.005 &lt; 0.005 &lt; 0.005 0.15 1.10 45 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt;0.005 0.150 0.010 &lt;0.01 46 &lt;0.005 &lt;0.005 0.01 0.20 0.010 0.010 &lt;0.01 47 &lt;0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.005 &lt; 0.01 48 0.010 0.010 0.010 0.40 0.050 0.020 0.12 49 &lt;0.005 &lt;0.005 &lt;0.005 &lt;0.005 &lt;0.005 &lt;0 .005 0.02 50 &lt;0.005 &lt;0.005 &lt;0.005 0.18 0.09 0.01 0.10 -21 - 200932412

[Table 5-1] No Weld penetration poor peeling rate % Slag amount g Tensile strength Mpa Absorbed energy J Arc stability Spoil amount g Cracked pores No 220 8.4〇572〇146〇〇4.0〇No M 2 No 24〇 9.2〇600〇164〇◎ 3.7〇Μ /w\ M y\\\ 3 No 20〇10.6〇536〇155〇〇4.5〇/ill* Mil. No 4 No 15〇10.50 608〇174〇〇4.6〇杯/1 No 5 No 16〇11.8〇575〇11〇〇〇4.9〇, N Μ 6 and JIW 29〇9_0〇496〇122〇◎ 3.5〇Αιττ &gt;1 SN No real 7 No 22〇10.30 595〇73 〇◎ 5.8〇无〇 JiS\施8 Charm 150 11.20 556〇74〇〇4.3〇Μ /w\ Μ Example 9 None 19〇11.6〇599〇72〇〇5.3〇无Μ /»w 10 1111* 20〇10.00 628〇73〇◎ 3.7〇Μ /\\\ 11 No 21〇7.5〇605〇75〇〇5.9〇无Μ &gt;1, 12 4m 20〇8.5〇555〇145〇〇5.0〇Μ. Μ 13 None 19〇9.6〇588〇71〇◎ 4.5〇Μ No 14 and M, 21〇8.00 598〇124〇〇4.6〇M y\\\ 15 No 22〇8.4〇574〇1500 〇4.2〇无Μ16 No 18〇7.7〇560〇123〇◎ 4.9〇1MI' Ji\\ No 17 1111* 150 9.0〇555〇167〇〇4.2〇^11 V Π1 r \\ No 18 No 17〇10.20 581〇1〇〇〇◎ 5.0〇没有-22- 200932412

[Table 5-2]

No Welding penetration poor peeling rate % Melting halo g Tensile strength Mpa Absorbing energy j Arc stability Splash amount g Cracking hole 19 No 20〇8.5〇485χ 132〇◎ 4.70 4m- /i\\ No 20 No 17〇10.40 615 〇65χ X 6.6x with or without 21 Arrf. Heat 14χ 7.5〇486χ 144〇X 5.1〇M /\w There are 22 Μ 28〇12_2χ 604〇63χ X 5.5〇^w\ Μ /\w 23 No 25〇6.2〇542〇 66χ 〇5.7〇4nr ITlt? There are 24 Μ 12χ 12.6χ 629〇Π9〇X 5.1〇无&gt;1, N 25 yfrrr. IHI- 27〇5.8〇555〇91〇X 6.4x ill!' /iw Μ y\ \\ 26 has 15〇11.5〇587〇135〇◎ 3.9〇illr Μ 27 has 150 11.30 596〇139〇〇4.4〇无Μ /\w 28 Jnt- no 14χ 12.4χ 6100 124〇X 4.9〇No 29 Αττ No 14χ 10.70 576〇1600 X 3.8〇无和30 No 20〇9.1〇535〇67χ X 5.1〇Se 31 No 17〇8.3〇546〇75〇〇5.4〇Am Itn? Sichuan, 32 ΊΠγ 22〇9.0〇 524〇76χ 〇5.2〇With or without 33 No 190 10.00 600〇142〇X 6.4x No incomparable 34 No 14χ 9.1〇561〇83 〇X 5.2〇有Μ/*\Ν Compared with 35 no 17〇8.5〇485χ 65χ 〇4.2〇无Μ &gt;1 \Ν Example 36 4nf No 20〇9.2〇602〇1500 ◎ 4.4〇有373713χ12.5χ 641 〇89〇X 4.1〇ίΕΕ 38 No 21〇7.9〇572〇68χ ◎ 5.2〇无和/\\\ 39 No 19〇8.7〇598〇64χ ◎ 5.00 Μ No 40 Μ 180 9.5〇609〇65χ ◎ 5.2〇 ΙΓ hot Μ j\w 41 no 22 〇 8.1 〇 〇 〇 χ » 〇 〇 τ τ » » » » » » » » » γ γ y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y y 9.1〇614〇69χ ◎ 4.4〇无无44 Μ y«\\ 14χ 8.5〇599〇129〇X 5.7〇无Μ 45 There are 5χ 11.00 484χ 66χ X 5.2〇Μ 夕》, Μ 46 χ11χ 11.20 486χ 64χ X 4.3〇益 w There are 47 Μ 20〇4.5〇480χ 42χ X 12.5x There are 48 9χ 1〇.4〇625〇60χ X 3.9〇Μ /»Λ\ There are 49 No 28〇12.3χ 479χ 49χ X 9.8x Yes No 50 Μ &lt;Μ,Ν 7χ 10.10 488χ 155〇X 5.1〇有-23-200932412 As shown in Table 5, the embodiments 1 to 18 of the present invention, each The composition range is within the specification of the present invention. Therefore, the slag removability, the slag amount, the strength of the weld metal, the toughness, the arc stability, the low spatter property, the weld penetration property, and the crack resistance are all good. Excellent weld workability and excellent mechanical properties of the weld metal are obtained. On the other hand, Comparative Examples 19 to 50 deviated from the scope of the present invention, in which Comparative Example 19 had too little C and the strength of the welded metal was insufficient. In Comparative Example 20, C 〇 was excessive, and high-temperature cracks occurred in the welded metal, and the strength was excessive and the toughness was low. In addition, there are many spatters and the arc stability is poor, so the continuous weldability is also deteriorated. In Comparative Example 21, Si was too small, the strength of the weld metal was insufficient, and the slag removability was also poor, and the slag interference caused the arc to be unstable and the continuous weldability was poor. In addition, pores also occur due to insufficient deoxygenation. In Comparative Example 22, Si was excessive, the toughness of the welded metal was insufficient, the amount of molten slag was excessive and interference was caused, the arc was unstable, and the continuous weldability was poor. In Comparative Example 23, the enthalpy η was too small, the toughness was low, and pores were generated due to insufficient deoxidation. In Comparative Example 24, the Μη was excessive, the amount of slag was large, and the peeling property was also poor. In addition, slag interference makes the arc unstable and has poor continuous weldability. In Comparative Example 25, the amount of spatter was too small, the amount of spatter generated was large, the arc stability was poor, and the tip was likely to be clogged, so that the continuous weldability was poor. In Comparative Examples 26 and 27, Ti was excessive, and the droplet transfer became a complete spherical droplet transfer, so that a large number of poor penetration of the weld occurred. In Comparative Example 28, although the respective components of Mn and Ti were each in compliance with the predetermined range, the parameter PMT was too large, so that the amount of slag was large and the peeling property was also poor. In addition, the slag interferes to make the arc unstable and the continuous fusion property is poor. In Comparative Example 29, the S was too small, the slag had poor peelability, the slag was disturbed, the arc was unstable, and the continuous weldability was poor. In Comparative Example 30, the S was excessive, and -24-200932412 was low in toughness, and high temperature cracks also occurred. Although the slag has good peelability, the deposit is granulated and the thickness is increased to impair the stability of the arc. As a result, the continuous weldability is poor. In Comparative Example 31, although the respective components of S and B were in compliance with the scope of the present invention, the parameter PBS was too large, so that the crack resistance was poor and cracking occurred. Comparative Example 32 had a P excess, low toughness, and high temperature cracking also occurred. In Comparative Example 33, the Cu content was too small, and the thickness of the copper-ammonium layer was thin, so that the conductivity was poor. Micro © Small fusion occurs in a large amount to make the arc unstable and the spatter increases. In Comparative Example 34, Cu was excessive, high-temperature cracks occurred, and slag removability was also poor, and slag interference caused arc instability and poor continuous weldability. Comparative Example 3 5 has insufficient B and insufficient strength and toughness. Comparative Example 3 6 has a B excess and a high temperature crack occurs. In Comparative Example 37, each of the Mn, Ti, B, and S elements was individually within the prescribed range of the present invention, but the parameters Pmt and PBS were outside the scope of the present invention. Therefore, the amount of slag is large, and the slag removability is also poor. In addition, the slag dry G disturbance causes the arc to be unstable, the continuous weldability is poor, and high temperature cracks also occur. In Comparative Examples 38 to 40, Nb and V 'A1 were excessive, and the toughness was lowered. In Comparative Examples 41 to 43, Mo, Cr, and Ni were excessive, and although the strength was increased, the strength was excessive, and conversely, the enthalpy was lowered. In Comparative Example 44, the Mo S2 adhesion amount was excessive, and MoS2 accumulation clogging occurred in the feed system such as a conduit liner, and the electrode feeding was extremely unstable. As a result, the arc stability is deteriorated, and the slag distribution is uneven and adversely affected. The slag removability is lowered. As a result, the slag interferes and the continuous weldability deteriorates. In Comparative Example 45, the Ti excess 'S was too small, and B was not added. Therefore, the surplus of Ti from -25 to 200932412 causes the droplet transfer to become a complete spherical droplet transfer, so that a large number of poor penetration of the weld occurs. In addition, since s is too small, the slag removability is also poor. In addition, slag interference makes the arc unstable and has poor continuous weldability. In addition, since B is not added, strength and toughness are insufficient. In Comparative Example 46, Ti was excessive, and S and Μη were too small. Since the excess of Ti causes the droplet to migrate into a complete spherical droplet transfer, the fusion penetration is largely caused. In addition, since S is too small, the peelability is also poor. The slag interference makes the arc unstable, and the continuous fusion is poor. Since Μη is too small, strength and tropism are insufficient, and stomata also occur due to insufficient oxygenation. In Comparative Example 47, c excess Μη was insufficient, and Ti and Β were not added. Therefore, insufficient strength and toughness due to insufficient Μη and no addition of Β' cause stomata due to insufficient deoxidation. High temperature cracks occur due to excess C, and the addition of Ti' does not result in a large amount of spatters. In Comparative Example 48, Ti, Pmt, and Mo were excessive but Si and S were insufficient. Therefore, since the excess of Ti causes the droplet transfer to become a complete spherical droplet transfer Ο, a large number of poor penetration of the weld occurs. In addition, since the Si and S are too small, the slag removability is also poor. The slag interference makes the arc unstable, and the continuous weldability is poor. In addition, excess Mo leads to insufficient toughness. In addition, due to insufficient si, deoxygenation is insufficient, and pores also occur. In Comparative Example 49, Si and S were excessive, Ti was insufficient, and B was not added. Since B is not added, the toughness is lowered and the strength is also low. Since Si and S are excessive, the amount of slag is large and granulated to impair arc stability. As a result, the continuous weldability is poor. In addition, a large amount of flying spatter occurs due to insufficient Ti. Because of the excess of S, high temperature cracks also occur. In Comparative Example 50, Si was insufficient, B was excessive, and PBS was too large. Welding due to insufficient Si -26- 200932412 The strength of the metal is insufficient, the slag peeling property is also poor, the slag interference makes the arc unstable, and the continuous welding property is poor. Porosity also occurs due to insufficient deoxidation due to insufficient Si. In addition, because the PBS is too large, high temperature cracks can also occur. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a graph showing the influence of the amount of Ti in the composition of the electrode and the protruding length of the electrode on the penetration depth of the weld. © Fig. 2 is a view showing ranges of B and S in the present invention. Fig. 3 is a view showing the range of Μη and Ti in the present invention. The fourth (a), (b) and (e) drawings show the shape of the welded test piece and the shape of the groove. Fig. 5 is a taken position of the welded metal tensile test piece. Figure 6 is the taken position of the welded metal Charpy impact test piece. [Main component symbol description] 1 : Partition ❹ 2 : Liner 3 : Steel pipe 4 : Welding torch -27-

Claims (1)

200932412 X. Patent application range 1·-δ = solid electrode for welding carbon oxide gas, characterized in that it contains c: 0.03 ~ 〇.1 〇 mass%, Si: 0.67 1.00 1.00 mass%, Μη. 1.81 〜2· 5〇% by mass, s: 0.006 to 0.018% by mass, Ti: 〇·1〇〇~〇_150% by mass, B: 0.0015 to 0.0070% by mass, Cu including plating component: 0.1 〇 to 0.45% by mass, and remaining It is Fe and unavoidable impurities; © The parameters of butyl and PMT are in accordance with PBS S 10, PmtS 32 ' and define P: 0.020 mass% or less, Nb: 0.04 mass% or less, V: 0·04 mass °/ ° below, A1 : 〇.〇4 mass% or less, Pbs = [B]x[S]x 1 〇5 PMT = [Mn]x[Ti]xl 〇2 Here, '[] represents the content of the element in the electrode (quality%). 2. The solid electrode for carbon dioxide gas welding according to the first aspect of the invention, wherein the solid electrode is selected from the group consisting of Mo: 0.25 mass% or less, O^Cr: 0.25 mass% or less, and Ni··0.25 mass% or less. At least one of them. 3. The solid electrode for carbon dioxide gas welding according to claim 1 or 2, wherein, for every 10 kg of the electrode, there is 0.01 to 1.00 g of m〇s2 ° -28- on the surface of the electrode.