WO2015190574A1 - 肉盛溶接体 - Google Patents
肉盛溶接体 Download PDFInfo
- Publication number
- WO2015190574A1 WO2015190574A1 PCT/JP2015/066944 JP2015066944W WO2015190574A1 WO 2015190574 A1 WO2015190574 A1 WO 2015190574A1 JP 2015066944 W JP2015066944 W JP 2015066944W WO 2015190574 A1 WO2015190574 A1 WO 2015190574A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- mass
- less
- content
- weld metal
- base material
- Prior art date
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
- B23K35/24—Selection of soldering or welding materials proper
- B23K35/30—Selection of soldering or welding materials proper with the principal constituent melting at less than 1550 degrees C
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
- B23K35/24—Selection of soldering or welding materials proper
- B23K35/30—Selection of soldering or welding materials proper with the principal constituent melting at less than 1550 degrees C
- B23K35/3053—Fe as the principal constituent
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
- B23K35/24—Selection of soldering or welding materials proper
- B23K35/30—Selection of soldering or welding materials proper with the principal constituent melting at less than 1550 degrees C
- B23K35/3053—Fe as the principal constituent
- B23K35/308—Fe as the principal constituent with Cr as next major constituent
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K35/00—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting
- B23K35/22—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by the composition or nature of the material
- B23K35/24—Selection of soldering or welding materials proper
- B23K35/30—Selection of soldering or welding materials proper with the principal constituent melting at less than 1550 degrees C
- B23K35/3053—Fe as the principal constituent
- B23K35/308—Fe as the principal constituent with Cr as next major constituent
- B23K35/3086—Fe as the principal constituent with Cr as next major constituent containing Ni or Mn
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B32—LAYERED PRODUCTS
- B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
- B32B15/00—Layered products comprising a layer of metal
- B32B15/01—Layered products comprising a layer of metal all layers being exclusively metallic
- B32B15/011—Layered products comprising a layer of metal all layers being exclusively metallic all layers being formed of iron alloys or steels
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/001—Ferrous alloys, e.g. steel alloys containing N
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/02—Ferrous alloys, e.g. steel alloys containing silicon
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/04—Ferrous alloys, e.g. steel alloys containing manganese
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C38/00—Ferrous alloys, e.g. steel alloys
- C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
- C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
- C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
Definitions
- the present invention relates to an overlay welded body in which a weld metal is overlay welded to the surface of a base material. More specifically, the present invention relates to an overlay welded body in which an overlay overlay weld metal is formed on the surface of a ferritic heat resistant steel.
- Ferritic heat-resistant steel containing about 2 to 12% by mass of Cr which is a heat-resistant structural material, is used for pressure vessels used at high temperatures such as in chemical plants (see, for example, Patent Document 1).
- Heat-resistant structural materials such as ferritic heat-resistant steel have a fine metal structure called a tempered martensite structure formed by quenching and tempering treatment from an austenite phase.
- a large-sized pressure vessel is manufactured by producing a plurality of ring-shaped structures with such a heat-resistant structural material, and circumferentially welding them together and joining them.
- ferritic heat resistant steel is inferior in corrosion resistance to austenitic stainless steel containing, for example, 18% by mass or more of Cr, and has sufficient corrosion resistance for corrosion caused by polythionic acid or hydrogen sulfide generated in a chemical plant. It cannot be said that it has.
- austenitic stainless steel has a large coefficient of thermal expansion, there is a problem that it is not suitable for a thick member or a large forged product for high temperature applications. Therefore, conventionally, large pressure vessels used in chemical plants use ferritic heat-resistant steel as a base material, and an overlay weld metal made of austenitic stainless steel is formed on the contact surface with the corrosive components. Yes.
- post-weld heat treatment is performed after joining the base metals.
- fracture toughness of the peripheral weld is formed by PWHT. Will improve.
- PWHT post-weld heat treatment
- a base material with high heat resistance it is necessary to perform PWHT at a higher temperature.
- PWHT is performed at a high temperature, the build-up weld metal becomes brittle and the thermal stress during use at a high temperature is reduced. There is a problem that cracks are likely to occur in the overlay weld due to repeated loads.
- Patent Document 2 is intended to prevent peeling of the overlay weld metal focused on the influence of hydrogen, and is focused on the deformability as a mechanical property of the welded portion made of the base material and the weld metal. Not a thing.
- the main object of the present invention is to provide a built-up welded body with excellent bending cracking resistance of the welded portion.
- the present inventor examines the problem that the bending crack resistance of the overlay welded body deteriorates after high-temperature PWHT, and improves both the ductility of the interface region between the weld metal and the base metal and the ductility of the weld metal itself. As a result, the inventors have found that the bending cracking resistance of the welded portion is improved, and have reached the present invention. Specifically, since the ductility of the interface region is caused by the hardening of the interface layer due to the reaction between Cr of the weld metal and C of the base metal, the Cr content ratio and the C content ratio of the weld metal and base material It can be improved by setting the product to a specific range. In addition, the ductility of the weld metal can be improved by reducing the Mn content of the weld metal and setting the parameter value calculated from the content of each component of the weld metal within a specific range.
- the build-up welded body according to the present invention is a build-up welded body in which a weld metal is build-up welded to the surface of the base material, and the base material includes C: 0.07 to 0.12% by mass, Cr : 2.0 to 10% by mass, Mo: 0.5 to 1.5% by mass, V: 0.02 to 0.5% by mass and Nb: 0.01 to 0.2% by mass, and Si : 0.6 mass% or less, Mn: 1 mass% or less, P: 0.04 mass% or less, S: 0.02 mass% or less, Cu: 0.3 mass% or less, Ni: 0.6 mass% or less And N: restricted to 0.1% by mass or less, the balance being composed of Fe and inevitable impurities, the weld metal is Ni: 9-11% by mass, Cr: 18-21% by mass and Nb: In addition to containing 0.1 to 1% by mass, C: 0.08% by mass or less, Si: 1.0% by mass or less, Mn: 0.9% by mass or less, P: 0.0.
- the horizontal axis represents the product of the Cr content ratio and the C content ratio of the weld metal and base metal represented by Formula 4, and the vertical axis is calculated from the content of each component of the weld metal represented by Formula 3. It is a graph which shows the relationship of these values in each test body of an Example and a comparative example, taking a parameter.
- the build-up welded body of the present embodiment is a structure that requires heat resistance such as a pressure vessel used at a high temperature, and a weld metal is build-up welded on the surface of the base material. It is an overlay welded joint.
- the base metal in the overlay welded body of the present embodiment is C: 0.07 to 0.12 mass%, Cr: 2.0 to 10 mass%, Mo: 0.5 to 1.5 mass%, V: 0 0.02 to 0.5 mass% and Nb: 0.01 to 0.2 mass%, Si: 0.6 mass% or less, Mn: 1 mass% or less, P: 0.04 mass% or less, S: 0.02% by mass or less, Cu: 0.3% by mass or less, Ni: 0.6% by mass or less, and N: 0.1% by mass or less, with the balance being Fe and inevitable impurities Have.
- the weld metal is Ni: 9 to 11 mass. %, Cr: 18-21% by mass and Nb: 0.1-1% by mass, C: 0.08% by mass or less, Si: 1.0% by mass or less, Mn: 0.9% by mass or less , P: 0.04 mass% or less, S: 0.03 mass% or less, Cu: 0.75 mass% or less, Mo: 0.75 mass% or less, V: 0.15 mass% or less, N: 0.0.
- the austenitic stainless steel has a composition that is limited to 08% by mass or less, the balance is Fe and inevitable impurities, and satisfies the following formula 3.
- [Cr] in the above formula 3 is the Cr content (mass%)
- [Mo] is the Mo content (mass%)
- [Si] is the Si content (mass%)
- [Nb] is the Nb content ( Mass%)
- [Mn] is the Mn content (mass%)
- [Ni] is the Ni content (mass%)
- [C] is the C content (mass%).
- the relationship between the Cr and C contents in the weld metal and the Cr and C contents in the base material satisfies the following mathematical formula 4.
- [Crw] in the following formula 4 is the Cr content (mass%) of the weld metal
- [Crm] is the Cr content (mass%) of the base material
- [Cw] is the C content (mass%) of the weld metal
- [Cm] is the C content (mass%) of the base metal.
- Base material As the base material, a base material that is usually used in the application of the overlay welded body of the present embodiment can be used, and specifically, a steel material having the above-described component composition is used. It should be noted that the components to be regulated, Si, Mn, P, S, Cu, Ni, and N, may not be contained at all (that is, 0% by mass), but the production cost is increased to reduce them extremely. From the viewpoint of cost-effectiveness, the lower limit does not include 0% by mass. Examples of the steel having such a component composition include heat resistant steels excellent in high temperature strength and long-term reliability, such as 2.25Cr-1Mo steel, 2.25Cr-1Mo-V steel, and 9Cr-1Mo-V steel.
- Ni is one of the essential elements for stainless steel and has the effect of stabilizing the austenite phase.
- the austenite phase may not be maintained.
- the Ni content of the weld metal exceeds 11% by mass, the manufacturing cost increases, and the ferrite phase in the weld metal may be excessively reduced. Therefore, the Ni content of the weld metal is 9 to 11% by mass.
- Cr 18 to 21% by mass> Cr is an element that improves the corrosion resistance, and is one of the essential elements for stainless steel.
- the Cr content of the weld metal is less than 18% by mass, it becomes difficult to exhibit basic corrosion resistance as stainless steel, and when it exceeds 21% by mass, the ferrite phase in the weld metal can be maintained. May cause hot cracking. Therefore, the Cr content of the weld metal is 18 to 21% by mass.
- Nb is one of the elements that improves the corrosion resistance of stainless steel by fixing carbon in the weld metal.
- the Nb content of the weld metal is less than 0.1% by mass, carbon fixation is insufficient, and when it exceeds 1% by mass, the amount of solid solution Nb may increase and the amount of ferrite may be excessively increased. . Therefore, the Nb content of the weld metal is 0.1-1% by mass.
- C is an element that combines with Cr to form a compound. And when C content of a weld metal exceeds 0.08 mass%, the amount of solid solution Cr will reduce locally and will cause a corrosion-resistant fall. Therefore, the C content of the weld metal is regulated to 0.08% by mass or less. In addition, C is an element contained in the weld metal even if it is contained in the welding material and flux and not added positively. In order to reduce the C content excessively, a large amount of cost is involved. Therefore, from the viewpoint of cost effectiveness, the C content is preferably set to 0.005% by mass or more.
- Si is an element that promotes the formation of the ⁇ phase.
- the Si content of the weld metal is regulated to 1.0% by mass or less.
- the Si content is preferably 0.1% by mass or more, more preferably 0.15% by mass or more. .
- Mn is an important element for obtaining a part of the effect of the present invention, and cracking occurs in the weld metal by regulating the Mn content to 0.9 mass% or less in the weld metal satisfying the above mathematical formula 3. Can be suppressed.
- Mn content shall be 0.8 mass% or less from a viewpoint of the ductility improvement of a weld metal, More preferably, it is 0.7 mass% or less.
- the Mn content is preferably 0.2% by mass or more.
- Mo is an element that improves the corrosion resistance.
- the weld metal contains Mo with dilution of the base material, and the Mo content is 0.75 mass. If it exceeds%, the weld metal tends to become brittle. Therefore, the Mo content in the weld metal is regulated to 0.75 mass% or less.
- the Mo content is preferably 0.05% by mass or more.
- V is an element that strongly stabilizes ferrite. If the V content exceeds 0.15% by mass, the ferrite in the weld metal excessively increases. Therefore, the V content of the weld metal is regulated to 0.15% by mass or less. V may not be contained in the weld metal at all (that is, 0% by mass), but an extremely low reduction is accompanied by an increase in manufacturing cost. Therefore, from the viewpoint of cost effectiveness, the lower limit of the V amount does not include 0 mass%. A more preferred lower limit is 0.01% by mass.
- P is an inevitable impurity, and when the P content exceeds 0.04% by mass, weld cracks are likely to occur in the weld metal. Therefore, the P content of the weld metal is regulated to 0.04% by mass or less. P may not be contained in the weld metal at all (that is, 0% by mass). However, since it is inevitably mixed, an increase in manufacturing cost is accompanied by an extreme reduction. Therefore, from the viewpoint of cost effectiveness, the lower limit of the amount of P does not include 0 mass%. A more preferred lower limit is 0.005% by mass.
- S is an inevitable impurity, and when the S content exceeds 0.03% by mass, the weld metal becomes brittle. Therefore, the S content of the weld metal is regulated to 0.03% by mass or less. S may not be contained in the weld metal at all (that is, 0% by mass), but since it is inevitably mixed, an increase in manufacturing cost is accompanied by an extreme reduction. Therefore, from the viewpoint of cost effectiveness, the lower limit of the amount of S does not include 0% by mass. A more preferred lower limit is 0.003% by mass.
- Cu is an unavoidable impurity, and if the Cu content exceeds 0.75 mass%, the weld metal may be excessively cured. Therefore, the Cu content of the weld metal is regulated to 0.75% by mass or less. In addition, it is preferable to make Cu content into 0.50 mass% or less, More preferably, it is 0.20 mass% or less, More preferably, it is 0.05 mass% or less. Cu may not be contained in the weld metal at all (that is, 0% by mass). However, since it is inevitably mixed, an increase in manufacturing cost is accompanied by an extreme reduction. Therefore, from the viewpoint of cost effectiveness, the lower limit of the amount of Cu does not include 0% by mass. A more preferred lower limit is 0.01% by mass.
- N is one of the inevitable impurities, and when the N content of the weld metal exceeds 0.08% by mass, the solid solution amount of Cr is reduced by forming a nitride. Therefore, the N content of the weld metal is regulated to 0.08% by mass or less. N may not be contained in the weld metal at all (that is, 0% by mass). However, since it is inevitably mixed, an increase in manufacturing cost is accompanied by an extreme reduction. Therefore, from the viewpoint of cost effectiveness, the lower limit of the N amount does not include 0 mass%. A more preferred lower limit is 0.005% by mass.
- ⁇ Remainder> Components other than the above in the weld metal, that is, the balance are Fe and inevitable impurities.
- inevitable impurities include Sn, Pb, Sb, As, Se, Zn, Ca, Al, Mg, Ti, Zr, Y, Ta, Hf, in addition to the aforementioned P, S, Cu, and N.
- Examples include Sc, Co, and Ag. Even if these components are contained in the weld metal, the effect of the present invention is not affected.
- the ductility of the weld metal can be improved by setting the Mn content to 0.9% by mass or less and setting the weld metal to a composition that satisfies Equation 3 above.
- the composition By setting the composition to satisfy Formula 3, it is possible to suppress the occurrence of cracks in the ferrite phase present in the solidified structure generated by bending deformation after passing through a higher temperature PWHT.
- the composition of the weld metal does not satisfy the above formula 3, and the parameters shown in the left side of the formula 3 ([Cr] + [Mo] + 1.5 ⁇ [Si] + 0.5 ⁇ [Nb] + 2.5 ⁇ [ If the value of Mn] ⁇ 0.2 ⁇ [Ni] + 30 ⁇ [C]) exceeds 21.5, the ductility of the weld metal is insufficient when the PWHT condition is high, and cracks occur in the ferrite phase in the weld metal. Is likely to occur.
- the value of the parameter shown on the left side of Equation 3 is preferably 21 or less, and more preferably 20 or less.
- the Cr content and the C content For each of these, the concentration difference between the base metal and the weld metal is made small.
- the Cr content and C content of the base material, and the Cr content and C content of the weld metal are set to satisfy the above mathematical formula 4. Thereby, the ductility of the joint interface region between the base material and the weld metal can be improved.
- the value of ⁇ (Crw / Crm) ⁇ (Cm / Cw) ⁇ shown on the left side of Equation 4 is preferably 14 or less, more preferably 13 or less. is there.
- the build-up welded body of the present embodiment can be formed by build-up welding the base material having the above-described composition by, for example, SAW (submerged arc welding) or ESW (electroslag welding).
- the welding method is not limited to SAW and ESW, and any welding method may be applied as long as it is a method capable of obtaining a weld metal component having the above-described composition.
- the welding material used when forming the build-up welded body of the present embodiment can have a composition corresponding to the component of the weld metal, but Cr and Nb that are easily oxidized and consumed during welding are preliminarily determined. By increasing the concentration, the target component may be easily obtained. It is also possible to adjust the components of the weld metal by adding raw materials to the flux used during construction. The composition of the weld metal can also be adjusted by the type of flux and the addition of raw materials.
- the build-up welded body is a large apparatus
- a thin and wide strip electrode build-up welding material as the welding material.
- a belt-shaped welding material having a thickness of 0.8 mm or less and a width of 15 mm or more is used, a large area can be efficiently constructed compared to a linear welding material having a diameter of 2 mm.
- a metal can be formed.
- the manufacturing method of the base material is not particularly limited, but a quenching treatment in a temperature range where the austenite structure is formed and a tempering treatment in a temperature range where the austenite structure is not formed, a tempered martensite structure is obtained. It needs to be formed.
- the base material is made of a steel ingot by performing ingot and casting so as to have the component composition described above, and then subjected to a quenching treatment at a temperature condition of 1000 ° C. or higher for a plate material formed by hot working. Then, tempering can be performed at a temperature of about 600 to 750 ° C.
- the overlay welded body makes the content of each component contained in the base material and the weld metal, which are heat-resistant structural materials, within a specific range, and the base material and the weld metal in the above-described range. Since it is set as the composition which satisfy
- overlay welding was performed using base materials and strip electrodes having different component compositions, and the bending cracking resistance of the resulting overlay weld metal was evaluated.
- the base material is No. 1 in Table 1 below.
- Steel materials having the component compositions shown in A to M were prepared by melting, casting, and forging, subjected to quenching at 1020 to 1060 ° C., and then tempered at 670 to 775 ° C.
- the balance in the base material component composition shown in Table 1 below is Fe and inevitable impurities.
- the Cu content in each example was 0.3% by mass or less.
- the base materials A to H and J to M have compositions within the scope of the present invention.
- the base material of I is a comparative example in which the C content is outside the scope of the present invention.
- the evaluation was performed by roughly cutting the weld specimen prepared by the above-described method so that the thickness of the base material portion was 10 mm and the width in the direction perpendicular to the welding direction was 70 mm, and the welding direction was the test piece. What was sliced so as to be in the plate thickness direction was mechanically polished to prepare a bending test piece having a thickness described later. The dimensions of the bending test piece are 70 mm in length, 15 mm in width, and 3 mm in thickness. Of the 15 mm in width, 5 mm is a portion of the overlay weld metal.
- the bending test was carried out in the manner of three-point bending using a general-purpose tensile and compression testing machine. After placing the two rollers on the receiving side in parallel and horizontally with the pedestal of the testing machine, place a test piece on each roller, and push the punch with a semicircular tip into the center between the rollers. Bending deformation was applied. At this time, the direction of the test piece was such that the vertical (70 mm) side was perpendicular to the axial direction of the roller. That is, the punch was pushed in parallel to the welding direction.
- the plate thickness of the test piece was 1.5 mm, 2.5 mm, and 3.5 mm
- the radius of the punch tip was 2 mm, 3 mm, and 6 mm
- bending deformations with different curvatures were applied depending on each combination.
- the distance between the rollers was set to be the sum of the diameter of the punch tip and twice the thickness of the test piece.
- each specimen of the comparative example had a bending crack resistance of 17 or less, whereas each specimen of the example had a good bending crack resistance of 20 or more. It was.
- the specimen No. Nos. 12, 14, and 16 are comparative examples that satisfy Equation 3 but do not satisfy Equation 4.
- 8, 10, 19, and 20 are comparative examples that satisfy Equation 4 but do not satisfy Equation 3. Since these specimens have only 17 or less bending crack resistance, which is inferior to each specimen in the examples, the effects of the present invention can be obtained unless both Equation 3 and Equation 4 are satisfied. I can't understand.
- the overlay welded body of the present invention is excellent in the bending crack resistance of the welded portion after high temperature PWHT, and thus is useful for a pressure vessel of a chemical plant.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Arc Welding In General (AREA)
- Nonmetallic Welding Materials (AREA)
Abstract
Description
母材は、本実施形態の肉盛溶接体の用途において、通常使用されている母材を用いることができ、具体的には、前述した成分組成を有する鋼材が用いられる。なお、規制する成分であるSi、Mn、P、S、Cu、Ni及びNについては全く含まれていない(即ち0質量%)でも構わないが、極端に低減するには製造コスト増加が伴うため、費用対効果の観点からは、下限はいずれも0質量%を含まないものとなる。このような成分組成を有する鋼としては、2.25Cr-1Mo鋼、2.25Cr-1Mo-V鋼及び9Cr-1Mo-V鋼などの高温強度及び長期信頼性に優れた耐熱鋼が挙げられる。
<Ni:9~11質量%>
Niは、ステンレス鋼として必須の元素の1つであり、オーステナイト相を安定化させる効果がある。しかしながら、溶接金属のNi含有量が9質量%未満の場合、オーステナイト相を維持できない場合がある。一方、溶接金属のNi含有量が11質量%を超えると、製造コストの増加を招き、また、溶接金属中のフェライト相を過度に減少させてしまうこともある。よって、溶接金属のNi含有量は9~11質量%とする。
Crは、耐食性を向上させる元素であり、ステンレス鋼として必須の元素の1つである。しかしながら、溶接金属のCr含有量が18質量%未満の場合、ステンレス鋼としての基本的な耐食性を発揮することが難しくなり、また、21質量%を超えると、溶接金属中のフェライト相を維持できず高温割れをもたらす場合がある。よって、溶接金属のCr含有量は18~21質量%とする。
Nbは溶接金属中の炭素を固定してステンレス鋼の耐食性を向上させる元素のひとつである。しかしながら、溶接金属のNb含有量が0.1質量%未満の場合炭素の固定が不十分となり、1質量%を超えると固溶Nbが増加してフェライト量を過度に増加させてしまう場合がある。よって、溶接金属のNb含有量は0.1~1質量%とする。
Cは、Crと結合して化合物を形成する元素である。そして、溶接金属のC含有量が0.08質量%を超えると、固溶Cr量が局部的に減少し、耐食性の低下を招く。よって、溶接金属のC含有量は0.08質量%以下に規制する。なお、Cは、溶接材料やフラックスに含まれており、積極的に添加しなくても溶接金属に含有される元素である。C含有量を過度に低下させるためには、多大なコストが伴うため、費用対効果の観点から、C含有量は0.005質量%以上とすることが好ましい。
Siは、従来からσ相の形成を促進させる元素とされており、Si含有量が1.0質量%を超えると、溶接金属が脆化することがある。よって、溶接金属のSi含有量は1.0質量%以下に規制する。ただし、Siは、湯流れ性の確保の観点からも若干量含んでいることが望ましく、Si含有量は0.1質量%以上であることが好ましく、より好ましくは0.15質量%以上である。
Mnは、本発明の一部の効果を得るために重要な元素であり、上記数式3を満たす溶接金属においてMn含有量を0.9質量%以下に規制することにより、溶接金属で発生する割れを抑制することができる。なお、溶接金属の延性改善の観点から、Mn含有量は0.8質量%以下とすることが好ましく、より好ましくは0.7質量%以下である。ただし、溶接金属のMn含有量を過度に低下させることは、コスト増加をもたらすため、Mn含有量は0.2質量%以上とすることが好ましい。
Moは、耐食性を向上させる元素であるが、本発明はMoを含む母材を対象としているため、母材の希釈に伴い溶接金属がMoを含有してしまい、Mo含有量が0.75質量%を超えると、溶接金属が脆化しやすくなる。よって、溶接金属のMo含有量は0.75質量%以下に規制する。ただし、溶接金属のMo含有量を過度に低下させることは、コスト増加をもたらすため、Mo含有量は0.05質量%以上とすることが好ましい。
Vは、フェライトを強く安定化させる元素であり、V含有量が0.15質量%を超えると、溶接金属中のフェライトが過度に増加してしまう。よって、溶接金属のV含有量は0.15質量%以下に規制する。溶接金属中にVは全く含まれていない(即ち0質量%)でも構わないが、極端に低減するには製造コスト増加が伴う。したがって、費用対効果の観点からは、V量の下限は0質量%を含まないものとなる。より好ましい下限は0.01質量%である。
Pは、不可避不純物であり、P含有量が0.04質量%を超えると、溶接金属に溶接割れが発生しやくなる。よって、溶接金属のP含有量は0.04質量%以下に規制する。溶接金属中にPは全く含まれていない(即ち0質量%)でも構わないが、不可避的に混入するものであるため、極端に低減するには製造コスト増加が伴う。したがって、費用対効果の観点からは、P量の下限は0質量%を含まないものとなる。より好ましい下限は0.005質量%である。
Sは、不可避的不純物であり、S含有量が0.03質量%を超えると、溶接金属が脆化する。よって、溶接金属のS含有量は0.03質量%以下に規制する。溶接金属中にSは全く含まれていない(即ち0質量%)でも構わないが、不可避的に混入するものであるため、極端に低減するには製造コスト増加が伴う。したがって、費用対効果の観点からは、S量の下限は0質量%を含まないものとなる。より好ましい下限は0.003質量%である。
Cuは、不可避的不純物であり、Cu含有量が0.75質量%を超えると、溶接金属が過度に硬化してしまう場合がある。よって、溶接金属のCu含有量は0.75質量%以下に規制する。なお、Cu含有量は、0.50質量%以下にすることが好ましく、より好ましくは0.20質量%以下、更に好ましくは0.05質量%以下である。溶接金属中にCuは全く含まれていない(即ち0質量%)でも構わないが、不可避的に混入するものであるため、極端に低減するには製造コスト増加が伴う。したがって、費用対効果の観点からは、Cu量の下限は0質量%を含まないものとなる。より好ましい下限は0.01質量%である。
Nは、不可避不純物のひとつであり、溶接金属のN含有量が0.08質量%を超えると、窒化物を形成することでCrの固溶量を減少させてしまう。よって、溶接金属のN含有量は0.08質量%以下に規制する。溶接金属中にNは全く含まれていない(即ち0質量%)でも構わないが、不可避的に混入するものであるため、極端に低減するには製造コスト増加が伴う。したがって、費用対効果の観点からは、N量の下限は0質量%を含まないものとなる。より好ましい下限は0.005質量%である。
溶接金属における上記以外の成分、即ち、残部は、Fe及び不可避的不純物である。ここで、不可避的不純物としては、前述したP、S、Cu及びNの他に、Sn、Pb、Sb、As、Se、Zn、Ca、Al、Mg、Ti、Zr、Y、Ta、Hf、Sc、Co及びAgなどが挙げられ、溶接金属にこれらの成分が含まれていても、本発明の効果には影響しない。
溶接金属の延性は、Mn含有量を0.9質量%以下とした上で、溶接金属を上記数式3を満足する組成とすることで改善することができる。上記数式3を満足する組成にすることで、より高温のPWHTを経た後、曲げ変形で生じる凝固組織中に存在するフェライト相での亀裂発生を抑制することができる。
母材及び溶接金属の成分組成を前述した範囲にしても、肉盛溶接体の耐割れ性を十分に向上させることができるとは限らない。特に、高温のPWHTを行った肉盛溶接体の場合、母材と溶接金属の接合界面領域における延性が低下し、曲げ変形に伴ってこの領域で亀裂が発生することがある。
次に、本実施形態の肉盛溶接体の形成方法について説明する。本実施形態の肉盛溶接体は、前述した組成の母材を、例えばSAW(サブマージアーク溶接)やESW(エレクトロスラグ溶接)により、肉盛溶接することにより形成することができる。なお、溶接方法は、SAW及びESWに限定されるものではなく、前述した組成の溶接金属成分を得られる方法であればよく、各種溶接方法を適用することができる。
母材は、下記表1のNo.A~Mに示す成分組成の鋼材を、溶解・鋳造、鍛造加工によって作製し、1020~1060℃で焼入処理を行った後、670~775℃で焼戻し処理を行うことにより作製した。なお、下記表1に示す母材成分組成における残部は、Fe及び不可避的不純物である。表中にCuの記載は無いが、いずれの例においてもCu含有量は0.3質量%以下であった。また、No.A~H,J~Mの母材は本発明の範囲内の組成を有するが、No.Iの母材はC含有量が本発明の範囲を外れた比較例である。
上記表1に示すNo.A~Mの各母材の表面に、75mm幅の帯状電極を用いたESW(エレクトロスラグ溶接)方式の肉盛溶接によって、厚さが約5mmの肉盛溶接金属を形成した。溶接条件は、電流を1400A、溶接速度を18cm/分、1層盛りとした。そして、溶接後に、PWHTとして775℃の温度条件で32時間の熱処理を実施し、評価用の溶接試験体とした。
評価は、前述した方法で作製した溶接試験体を、母材部分の厚さが10mm、溶接方向に対して垂直な方向の幅が70mmとなるように粗切断し、更に溶接方向が試験片の板厚方向となるようスライス加工を行ったものを機械研磨して、後述する厚さの曲げ試験片を作製した。この曲げ試験片の寸法は、縦70mm、横15mm、厚さ3mmであり、横15mmのうち5mmが肉盛溶接金属の部分である。
本出願は、2014年6月11日出願の日本特許出願(特願2014-120757)に基づくものであり、その内容はここに参照として取り込まれる。
Claims (1)
- 母材の表面に溶接金属が肉盛溶接された肉盛溶接体であって、
前記母材は、C:0.07~0.12質量%、Cr:2.0~10質量%、Mo:0.5~1.5質量%、V:0.02~0.5質量%及びNb:0.01~0.2質量%を含有すると共に、Si:0.6質量%以下、Mn:1質量%以下、P:0.04質量%以下、S:0.02質量%以下、Cu:0.3質量%以下、Ni:0.6質量%以下及びN:0.1%質量以下に規制され、残部がFe及び不可避的不純物からなる組成を有し、
前記溶接金属は、Ni:9~11質量%、Cr:18~21質量%及びNb:0.1~1質量%を含有すると共に、C:0.08質量%以下、Si:1.0質量%以下、Mn:0.9質量%以下、P:0.04質量%以下、S:0.03質量%以下、Cu:0.75質量%以下、Mo:0.75質量%以下、V:0.15質量%以下及びN:0.08質量%以下に規制され、残部がFe及び不可避不純物からなり、Cr含有量(質量%)を[Cr]、Mo含有量(質量%)を[Mo]、Si含有量(質量%)を[Si]、Nb含有量(質量%)を[Nb]、Mn含有量(質量%)を[Mn]、Ni含有量(質量%)を[Ni]、C含有量(質量%)を[C]としたとき、下記数式(A)を満たす組成を有し、
前記溶接金属のCr含有量(質量%)を[Crw]、前記母材のCr含有量(質量%)を[Crm]、前記溶接金属のC含有量(質量%)を[Cw]、前記母材のC含有量(質量%)を[Cm]としたとき、下記数式(B)を満たす肉盛溶接体。
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1020167034102A KR20170002567A (ko) | 2014-06-11 | 2015-06-11 | 육성 용접체 |
CN201580027517.2A CN106413977A (zh) | 2014-06-11 | 2015-06-11 | 堆焊体 |
EP15806825.4A EP3156170A4 (en) | 2014-06-11 | 2015-06-11 | Buildup welded body |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2014120757A JP6244267B2 (ja) | 2014-06-11 | 2014-06-11 | 肉盛溶接体 |
JP2014-120757 | 2014-06-11 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2015190574A1 true WO2015190574A1 (ja) | 2015-12-17 |
Family
ID=54833660
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2015/066944 WO2015190574A1 (ja) | 2014-06-11 | 2015-06-11 | 肉盛溶接体 |
Country Status (5)
Country | Link |
---|---|
EP (1) | EP3156170A4 (ja) |
JP (1) | JP6244267B2 (ja) |
KR (1) | KR20170002567A (ja) |
CN (1) | CN106413977A (ja) |
WO (1) | WO2015190574A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2018061779A1 (ja) * | 2016-09-30 | 2018-04-05 | 株式会社神戸製鋼所 | 鉄鋼部品およびその製造方法ならびに鉄鋼部品用の鋼板 |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP6257454B2 (ja) * | 2014-06-11 | 2018-01-10 | 株式会社神戸製鋼所 | 肉盛溶接金属及び機械構造物 |
JP2019158167A (ja) * | 2018-03-07 | 2019-09-19 | Jfeエンジニアリング株式会社 | ボイラの放射伝熱面の防食方法及びボイラ |
CN114571134B (zh) * | 2022-03-08 | 2023-04-25 | 江苏省徐州技师学院 | 一种用于硬质合金刀具钎焊的钎焊材料及其制备方法 |
Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS58199847A (ja) * | 1982-05-15 | 1983-11-21 | Nippon Steel Corp | 耐デイスボンデング特性の優れた圧力容器用鋼 |
JPS60121098A (ja) * | 1983-12-05 | 1985-06-28 | Kawasaki Steel Corp | オ−ステナイト系ステンレス鋼肉盛溶接における水素はくり割れ防止方法 |
JPS61115674A (ja) * | 1984-11-08 | 1986-06-03 | Kawasaki Steel Corp | 耐はく離割れ性に優れたオ−ステナイト系ステンレス鋼一層肉盛溶接方法 |
JPS6264493A (ja) * | 1985-09-18 | 1987-03-23 | Toshiba Corp | 高温用溶接構造物 |
JPS6268693A (ja) * | 1985-09-24 | 1987-03-28 | Toshiba Corp | 高温用溶接構造物 |
JPS6369941A (ja) * | 1986-09-09 | 1988-03-30 | Nippon Kokan Kk <Nkk> | 耐デイスボンデイング性の優れたオ−バ−レイクラツド鋼 |
JPS6410317B2 (ja) * | 1981-07-24 | 1989-02-21 | Kobe Steel Ltd |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6026632B2 (ja) * | 1982-04-22 | 1985-06-25 | 川崎製鉄株式会社 | オ−ステナイト系ステンレス鋼による肉盛り溶接方法 |
JP2684109B2 (ja) | 1990-03-13 | 1997-12-03 | 株式会社 日本製鋼所 | 高温高圧用低合金鋼を母材とした剥離抵抗性の優れたオーバレイステンレスクラッド鋼 |
CN100460133C (zh) * | 2007-05-23 | 2009-02-11 | 山东大学 | 一种堆焊用合金粉块 |
JP5917312B2 (ja) | 2012-06-20 | 2016-05-11 | 株式会社東芝 | 蒸気弁装置およびその製造方法 |
JP6257454B2 (ja) * | 2014-06-11 | 2018-01-10 | 株式会社神戸製鋼所 | 肉盛溶接金属及び機械構造物 |
-
2014
- 2014-06-11 JP JP2014120757A patent/JP6244267B2/ja not_active Expired - Fee Related
-
2015
- 2015-06-11 CN CN201580027517.2A patent/CN106413977A/zh active Pending
- 2015-06-11 KR KR1020167034102A patent/KR20170002567A/ko active IP Right Grant
- 2015-06-11 EP EP15806825.4A patent/EP3156170A4/en not_active Withdrawn
- 2015-06-11 WO PCT/JP2015/066944 patent/WO2015190574A1/ja active Application Filing
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6410317B2 (ja) * | 1981-07-24 | 1989-02-21 | Kobe Steel Ltd | |
JPS58199847A (ja) * | 1982-05-15 | 1983-11-21 | Nippon Steel Corp | 耐デイスボンデング特性の優れた圧力容器用鋼 |
JPS60121098A (ja) * | 1983-12-05 | 1985-06-28 | Kawasaki Steel Corp | オ−ステナイト系ステンレス鋼肉盛溶接における水素はくり割れ防止方法 |
JPS61115674A (ja) * | 1984-11-08 | 1986-06-03 | Kawasaki Steel Corp | 耐はく離割れ性に優れたオ−ステナイト系ステンレス鋼一層肉盛溶接方法 |
JPS6264493A (ja) * | 1985-09-18 | 1987-03-23 | Toshiba Corp | 高温用溶接構造物 |
JPS6268693A (ja) * | 1985-09-24 | 1987-03-28 | Toshiba Corp | 高温用溶接構造物 |
JPS6369941A (ja) * | 1986-09-09 | 1988-03-30 | Nippon Kokan Kk <Nkk> | 耐デイスボンデイング性の優れたオ−バ−レイクラツド鋼 |
Non-Patent Citations (1)
Title |
---|
See also references of EP3156170A4 * |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2018061779A1 (ja) * | 2016-09-30 | 2018-04-05 | 株式会社神戸製鋼所 | 鉄鋼部品およびその製造方法ならびに鉄鋼部品用の鋼板 |
JP2018059190A (ja) * | 2016-09-30 | 2018-04-12 | 株式会社神戸製鋼所 | 鉄鋼部品およびその製造方法ならびに鉄鋼部品用の鋼板 |
Also Published As
Publication number | Publication date |
---|---|
CN106413977A (zh) | 2017-02-15 |
EP3156170A4 (en) | 2017-11-15 |
KR20170002567A (ko) | 2017-01-06 |
EP3156170A1 (en) | 2017-04-19 |
JP6244267B2 (ja) | 2017-12-06 |
JP2016000411A (ja) | 2016-01-07 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5984213B2 (ja) | 溶接性に優れる被覆管用オーステナイト系Fe−Ni−Cr合金 | |
KR102415777B1 (ko) | 2상 스테인리스 클래드 강판 및 그 제조 방법 | |
KR101345074B1 (ko) | Ni기 합금재 | |
JP6870749B2 (ja) | オーステナイト系ステンレス鋼溶接金属および溶接構造物 | |
US20190126408A1 (en) | Welding Structure Member | |
WO2015190574A1 (ja) | 肉盛溶接体 | |
JP5018863B2 (ja) | 耐アルカリ性に優れた二相ステンレス鋼 | |
JP5454723B2 (ja) | 耐海水腐食性に優れたステンレスクラッド鋼板の合せ材及びそれを用いたステンレスクラッド鋼板並びにその製造方法 | |
EP2803741B1 (en) | Method of post weld heat treatment of a low alloy steel pipe | |
JP6965938B2 (ja) | オーステナイト系ステンレス鋼溶接金属および溶接構造物 | |
JP6870748B2 (ja) | オーステナイト系ステンレス鋼 | |
EP3862456A1 (en) | Clad austenitic stainless steel sheet, base steel sheet and method for producing clad steel sheet | |
JP6494745B2 (ja) | ステンレス鋼溶接継ぎ手および燃料改質器用ステンレス鋼 | |
US20190105727A1 (en) | Welding Structure Member | |
JP6257454B2 (ja) | 肉盛溶接金属及び機械構造物 | |
RU2451588C2 (ru) | Сварочная проволока для автоматической сварки теплоустойчивых сталей перлитного класса | |
KR20190062488A (ko) | 오스테나이트계 내열 합금 및 그것을 이용한 용접 이음매 | |
JP4465066B2 (ja) | フェライト・オーステナイト二相系ステンレス鋼用溶接材料 | |
JP2022038084A (ja) | クラッド鋼板およびその製造方法ならびに溶接構造物 | |
JP6172077B2 (ja) | 耐粒界腐食特性に優れたNi合金クラッド鋼の製造方法 | |
JP7357761B2 (ja) | クラッド鋼板およびその製造方法ならびに溶接構造物 | |
JP2018176195A (ja) | 熱延工場サイドガイド部材 | |
JP6462431B2 (ja) | 肉盛溶接金属及び機械構造物 | |
EP2803743B1 (en) | Low alloy steel |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 15806825 Country of ref document: EP Kind code of ref document: A1 |
|
REEP | Request for entry into the european phase |
Ref document number: 2015806825 Country of ref document: EP |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2015806825 Country of ref document: EP |
|
ENP | Entry into the national phase |
Ref document number: 20167034102 Country of ref document: KR Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |