JP4999515B2 - Chrome-containing steel for container material, welding method thereof, and container material - Google Patents

Description

  The present invention is a container material, in particular, a container material for storing a solution comprising a water phase having a pH of 3 to 12 containing halide ions of 200 ppm by mass or less, specifically, as a material for a water-based paint storage container. The present invention relates to a chromium-containing steel to be used, and relates to a chromium-containing steel excellent in the corrosion resistance and toughness of a weld where deterioration of corrosion resistance and toughness is a problem, a welding method thereof, and a container material.

  As a steel container material, painted iron is generally used. However, when the content is an aqueous solution, the coated iron may corrode from the defective film portion. In particular, when coated iron is used as a storage container material for water-based paints containing an aqueous phase having a pH of 3 to 12 containing 0.01 to 200 ppm by weight of halide ions, corrosion from coating film defects is prevented. Occurrence is an unavoidable problem, and as an alternative material, the application of stainless steel having excellent corrosion resistance is considered.

  However, even in a stainless steel container having excellent corrosion resistance, the welded portion is a portion having poor corrosion resistance, and an aqueous paint containing an aqueous phase having a pH of 3 to 12 containing a halide ion of 0.01 to 200 ppm by mass is used. In the case of storage, the occurrence of corrosion at this weld is a problem. As a method for preventing the occurrence of corrosion at the welded portion of the stainless steel container, for example, in Patent Document 1 and Patent Document 2, the oxidation scale of the welded portion is removed using a mixed acid of nitric acid and hydrofluoric acid to improve the corrosion resistance. Is disclosed.

  In Patent Document 1 and Patent Document 2, there is no description about the type of stainless steel used in the stainless steel container, but the stainless steel used as the container material is usually SUS304 steel. In Patent Documents 1 and 2, it is considered that the stainless steel as a substantial object is SUS304 steel. However, since SUS304 steel is a stainless steel containing about 10% by mass of nickel, which has a high alloy cost, a stainless steel container using SUS304 steel has a significant cost increase compared to a coated iron container. This is one of the reasons why the application to stainless steel containers does not progress.

  In order to achieve a significant cost reduction compared with the current SUS304 steel, it is indispensable to reduce the raw material cost. For this purpose, it is desirable to apply chromium-free steel without addition of nickel. However, when the nickel-free chromium-containing steel is applied to a water-based paint storage container containing an aqueous phase having a pH of 3 to 12 containing 0.01 to 200 ppm by mass of halide ions, the corrosion resistance at the welded portion. Deterioration is remarkable, and even if the removal of the oxide scale layer using the mixed solution of nitric acid and hydrofluoric acid shown in Patent Documents 1 and 2 is carried out, there is a drawback that the corrosion resistance of the weld remains extremely low. there were. Furthermore, chromium-free steel with no nickel added has the disadvantage that the toughness of the weld is low.

  The present inventors tried to apply chromium-free steel without addition of nickel to an aqueous paint storage container comprising an aqueous phase having a pH of 3 to 12 containing 0.01 to 200 ppm by mass of halide ions. However, compared with SUS304 steel excellent in corrosion resistance, the deterioration of the corrosion resistance in the welded portion is remarkable, and unless the welded portion corrosion resistance is improved, a pH of 3 to 12 containing halide ions of 0.01 to 200 ppm by mass. It was confirmed that application of chromium-free steel without addition of nickel to a water-based paint storage container comprising an aqueous phase was impossible.

  Furthermore, the present inventors tried to increase the chromium concentration in the steel containing chromium without adding nickel in order to improve the corrosion resistance of the weld, but the corrosion resistance could be improved, but the toughness of the weld deteriorated. Therefore, it was confirmed that the necessary properties could not be satisfied for application to a water-based paint storage container comprising an aqueous phase having a pH of 3 to 12 containing 0.01 to 200 ppm by mass of halide ions. .

  That is, the container material for storage of water-based paints containing an aqueous phase having a pH of 3 to 12 containing halide ions of 0.01 to 200 ppm by mass has a low cost of the material and has a corrosion resistance at the same level as that of SUS304 steel. Further, welded portion toughness is desired, and although it is possible to cope with cost reduction with chromium-free steel containing no nickel, it is impossible to achieve both welded portion corrosion resistance and welded portion toughness. Therefore, at present, there is no chromium-containing steel that satisfies these characteristics. Furthermore, since the usual container forming method uses caulking, joining by resistance welding, or joining by a fusion welding method such as plasma, MIG, or TIG, the corrosion resistance deteriorates at the gap or the welded part or the welded part. The toughness of the steel is a problem.

Japanese Patent Publication No. 1-358080 Japanese Patent Publication No. 4-13218

  In order to meet the above-mentioned problems, the present invention can ensure welded portion corrosion resistance and welded portion toughness, and includes a container material, in particular, an aqueous phase having a pH of 3 to 12 containing 0.01 to 200 ppm by mass of halide ions. It is an object of the present invention to provide nickel-free chromium-containing steel, a welding method thereof, and a container material that are optimal in terms of cost as a material for a water-based paint storage container.

  The inventors have used chromium-containing steel with no nickel added as a container material, in particular, an aqueous paint storage container material comprising an aqueous phase having a pH of 3 to 12 containing 0.01 to 200 mass ppm of halide ions. Various studies were conducted to improve the corrosion resistance and toughness of the welded portion of the container material.

  As a result, in order to improve the corrosion resistance and toughness of the welded part, carbon and nitrogen in the steel are stabilized by adding more than a specified amount of titanium and / or niobium to the steel. It was newly found that the corrosion resistance and toughness of the steel were improved. Furthermore, it has been found that the addition of Al is effective in improving the corrosion resistance and toughness of the welded portion. Furthermore, it has been found that Ca and S are elements that cause a decrease in the corrosion resistance of the base metal and the corrosion resistance and toughness of the welded portion when added in a predetermined amount or more. And it discovered that the oxide scale produced | generated in the welding part and its peripheral part was easily removable by chemical treatment by implementing a back shield at the time of fusion welding. Further, it has been found that in order to prevent the occurrence of crevice corrosion at the joint, it is most effective to build up the gap.

The present invention has been achieved based on the above findings, and the gist thereof is as follows.
(1) Chromium-containing steel used for a container material for storing an aqueous paint containing an aqueous phase having a pH of 3 to 12 containing 0.01 to 200 ppm by mass of a halogen compound ion, wherein the steel is in mass%. Cr: 9 to 19% (excluding Cr: 9 to 11.2%) , N: 0.008% or more, C + N: 0.03% or less, Al: 0.002 to 0.2%, S: 0.01% or less, further containing Ti and Nb alone or in combination, and when the C + N content is x (mass%), Ti content y (mass%), and , Nb content z (mass%) is 8x ≦ y ≦ 0.6 and 18x ≦ z ≦ 0.6, respectively, when contained alone, and 1 <( y / 8x) + (z / 18x) and y + z ≦ 0.6 with the balance being Fe and Container material for chromium containing steel, characterized in that it consists avoidable impurities.
(2) The chromium-containing steel for container materials according to (1), wherein the chromium-containing steel further contains 0.005% by mass or less of Ca.
(3) The chromium for container materials according to (1) or (2), wherein the chromium-containing steel further contains 0.5 to 3% by mass of one or two of Mo and W. Containing steel.
(4) After performing melt welding on the chromium-containing steel for container materials according to any one of (1) to (3) above while performing backshielding using argon gas at a flow rate of 20 L / min or more, A method for welding chrome-containing steel for container materials, characterized by chemically removing the fusion weld and the oxide scale formed in the periphery thereof.
(5) After performing mechanical joining by resistance welding or caulking structure to the chromium-containing steel for container materials according to any one of (1) to (3), overlay welding is performed on the welded part or the joined part. A method for welding chromium-containing steel for container materials, characterized in that, further, thereafter, the build-up weld and the oxide scale formed around the weld are chemically removed.
(6) The build-up welding uses austenitic stainless steel as a welding rod, and the content of the welding rod is, by mass, Cr: 16-25%, Ni: 8-16%, C : 0.03% or less, N: 0.05% or less, Mn: 2.00% or less, the balance being Fe and inevitable impurities, and Cr equivalent and Ni equivalent satisfy the following formula The method for welding chrome-containing steel for container materials according to (5) above.
Cr equivalent × Ni equivalent> 160
(However, Cr equivalent = Cr (mass%) + Mo (mass%) + 1.5 Si (mass%), Ni equivalent = Ni (mass%) + 0.5 Mn (mass%) + 30 C (mass%) + 30 N (mass%), Mo and Si are contained as inevitable impurities.)
(7) A container material obtained by processing and forming the chromium-containing steel for container materials according to any one of (1) to (3).

  The present invention can provide welded portion corrosion resistance and welded portion toughness, and can provide a nickel-free chromium-containing steel that is optimal in terms of cost as a container material, a welding method thereof, and a container material.

  The container material of the present invention is intended for use in a water-based paint storage container comprising an aqueous phase having a pH of 3 to 12 containing a halide ion of 200 mass ppm or less. In conventional coated iron containers, damage due to corrosion becomes a problem particularly when the halide ion concentration is 0.01 mass ppm or more. Accordingly, the steel of the present invention is particularly intended for use in a water-based paint storage container comprising an aqueous phase having a pH of 3 to 12 and containing 0.01 to 200 ppm by mass of halide ions. The storage temperature is generally 60 ° C. or lower.

  The water-based paint comprising an aqueous phase having a pH of 3 to 12 containing halide ions of 200 ppm by mass or less may contain an oil phase, or may be an emulsion of the aqueous phase and the oil phase. Furthermore, you may mix | blend additives, such as a pigment.

  The reasons for limiting the additive components of the chromium-free steel with no nickel of the present invention will be shown below. In the following description, the component composition of steel and the amount of chemical substance are both mass%.

Chromium is an essential element for securing the corrosion resistance of the base material, and 9% or more of addition is necessary to develop the corrosion resistance. However, if added over 19%, the toughness of the welded portion is significantly reduced, so the upper limit is 19%. However, Cr: 9 to 11.2% is excluded.

  Carbon and nitrogen are elements that deteriorate the corrosion resistance and toughness of the welded portion, and the arithmetic sum x (% by mass) of these elements is set to 0.03% or less. However, in Table 1, based on the nitrogen concentration of the invention steel 7 of 0.008%, the lower limit of nitrogen is 0.008%.

  Titanium and niobium are elements added to stabilize carbon and nitrogen. Titanium and niobium are added alone or in combination. However, the addition amount Ti (mass%) of Ti and the addition amount z (mass%) of Nb are 8x ≦ y ≦ 0.6 and 18x ≦ z ≦ 0.6, respectively, in the case of single addition, and composite addition In this case, 1 <(y / 8x) + (z / 18x) and y + z ≦ 0.6. When the addition amount of titanium and niobium satisfies the above relational expression, stabilization is performed by fixing carbon and nitrogen of the base material, and accordingly, the corrosion resistance and toughness of the weld are improved. However, if the addition amount of titanium and niobium exceeds 0.6% by itself or in combination, it adversely affects toughness, so 0.6% is made the upper limit.

  Al is an additive element essential for improving the corrosion resistance of the base metal and the corrosion resistance and toughness of the weld. Al improves the corrosion resistance of the base metal and the corrosion resistance and toughness of the welded portion by adding 0.002% or more. However, if added over 0.2%, the corrosion resistance and toughness of the welded portion are lowered, so 0.2% is made the upper limit.

  S is an element that causes a decrease in the corrosion resistance of the base metal and the corrosion resistance and toughness of the weld. Accordingly, the S content needs to be 0.01% or less.

  The chromium-containing steel according to the present invention is Fe and unavoidable impurities other than the above-mentioned additive components, but in addition to the additive elements, Ca may be added as necessary. Ca is effective in improving the corrosion resistance and toughness of the welded portion. However, if more than 0.005% is added, the corrosion resistance of the base material and the corrosion resistance and toughness of the welded portion are reduced, so 0.005% is added. The upper limit.

  Further, in addition to the additive element, one or two of Mo and W may be added as necessary.

  Mo and W are additive elements effective for improving the corrosion resistance, and the improvement of the corrosion resistance is manifested by addition of 0.5% or more. However, if added over 3%, the strength of the material is significantly increased and the toughness is reduced, so 3% is made the upper limit. These elements can be added alone or in combination.

  Next, a method for welding the steel of the present invention will be described.

  The welding method targeted by the present invention is a joining method based on a general welding method as a container welding method.

  The fusion welding method means a MIG (Metal Inert Gas) welding method, a TIG (Tungsten Inert Gas) welding method, a laser welding method, and a plasma welding method. In general, a welded portion obtained by the fusion welding method is often inferior in corrosion resistance, but depending on welding conditions, a protective oxide scale is formed, which may contribute to improvement in corrosion resistance. The inventors of the present invention are related to the welding method of the steel of the present invention by fusion welding for improving the corrosion resistance of welds in an aqueous paint comprising a water phase of pH 3-12 containing halide ions of 200 mass ppm or less. As a result of intensive studies on the method, it has been found that the implementation of a back shield using argon gas is extremely effective in improving corrosion resistance when performing fusion welding.

  That is, the welding method of the steel of the present invention is a fusion welding method of MIG welding, TIG welding, laser welding, and plasma welding, but when performing fusion welding, back shielding using argon gas is performed. This is an indispensable measure for preventing deterioration of corrosion resistance due to oxygen and nitrogen in the atmosphere being taken into the welded portion, and the flow rate of argon gas is required to be 20 L / min or more. If it is less than 20 L / min, the shielding effect at the time of welding is insufficient, and an oxide scale that causes corrosion resistance deterioration is formed. Therefore, a flow rate of 20 L / min or more is required.

  However, even if the above-mentioned back shield is performed and fusion welding is performed, it is difficult to completely prevent a thin oxide scale from being partially formed around the welded portion. In the welding of the steel of the present invention, since the oxide scale is involved in the corrosion resistance reduction, the removal thereof is indispensable. By removing the oxide scale, the corrosion resistance of the welded portion is greatly improved.

  Examples of the method for removing the oxide scale according to the present invention include a mechanical or chemical removal method, but depending on the roughness of the steel material surface, the removal of the oxide scale may not be sufficiently performed only by the mechanical removal method. For this reason, it is preferable to apply a chemical removal method. Furthermore, in the welding method of the steel of the present invention, since the shielding by argon gas is performed at the time of welding, the thickness of the oxide scale formed is thin. Therefore, chemical pretreatment such as blasting and polishing is not performed. It is possible to remove the oxide scale by an automatic removal method.

  The chemical removal method according to the present invention is preferably treated with a mixed acid of nitric acid and hydrofluoric acid, and the concentrations of nitric acid and hydrofluoric acid are preferably 5 to 30% and 0.5 to 5%, respectively. If the nitric acid concentration is less than 5%, sufficient oxidizing power cannot be obtained, and the removal of the oxide scale becomes insufficient. However, if it exceeds 30%, the amount of NOx (nitrogen oxide) generated increases, which is not preferable. About less than 0.5% hydrofluoric acid, the effect of promoting the dissolution of steel is small, which is not preferable. However, even if added over 5%, the effect of promoting the dissolution of steel is almost saturated, so 5% is made the upper limit.

  Since the treatment temperature and the treatment time depend on the thickness of the oxide scale, it can be considered by visual observation that the oxide scale has been removed, that is, it can be considered that the colored portion has become metallic luster. It is preferable to select the treatment temperature and time.

  In a specific embodiment of the chemical treatment with the mixed acid of nitric acid and hydrofluoric acid, a paste containing nitric acid and hydrofluoric acid may be applied to the welded portion and the surrounding area, or nitric acid and hydrofluoric acid are included. The solution may be soaked in gauze, filter paper, etc., and attached to the welded part and the surrounding area. However, in the latter method, since the solution is easily volatilized, the paste is easier to handle.

In addition to the above method, electrolytic treatment using a neutral salt solution may be performed. Neutral salt electrolysis uses an aqueous solution in which an electrolyte such as 10-30% sodium nitrate or sodium sulfate is dissolved. The steel plate of the present invention and a stainless steel plate (for example, SUS304 steel) serving as a cathode are placed in an electrolytic cell containing the aqueous solution. It is preferable to carry out electrolysis by dipping and using the steel of the present invention as an anode at a current density of 0.05 to 3 A / cm ² until the removal of the oxide scale can be visually confirmed. If the current density is less than 0.05 A / cm ² , it is difficult to dissolve the oxide film in a passive state, and the oxide scale is likely to remain, which is not preferable. However, an electrolysis current density exceeding 3 A / cm ² is not preferable because the rate of electric power consumed for oxygen generation by electrolysis of water increases rather than overpassive dissolution. After electrolytic pickling, it is preferable to wash with water.

  After the chemical treatment, the weld may be further polished. By polishing, the surface roughness of the welded portion is reduced, which contributes to the improvement of the corrosion resistance of the welded portion. Polishing can be performed using a polishing belt or a carbon brush, but it is not preferable to use a material that does not contribute to improving the corrosion resistance of the welded portion. For example, an iron-based brush is not preferable because it causes rusting.

  The so-called passivation treatment in which the chemical treatment and / or polishing is performed and then immersed in a nitric acid solution not containing hydrofluoric acid or a paste containing the nitric acid is applied also improves the corrosion resistance. Works effectively. The nitric acid concentration is preferably 10 to 40% by mass. When the nitric acid concentration is less than 10% by mass, the oxidizing power is insufficient, and it is difficult to form a passive film with high protection mainly composed of chromium on the steel surface. If the concentration of nitric acid exceeds 40% by mass, the oxidizing power of nitric acid becomes extremely strong, which requires care for handling the chemical solution, which is not preferable.

  In addition to the above fusion welding, a resistance welding method such as seam welding or spot welding, or a mechanical joining method using a caulking structure can be applied to the welding method of the steel of the present invention.

  In the resistance welding method, the molten part does not directly contact the external environment and the welding time is short. Therefore, it is not necessary to perform a back shield as in the case of the above-mentioned fusion welding, but the oxidation generated by welding is not necessary. The chemical removal of the scale is indispensable, and the chemical removal method described above may be performed.

  Furthermore, in joining by resistance welding or caulking structure, it is necessary to prevent deterioration of corrosion resistance in the gap due to formation of a gap in the joint, that is, occurrence of crevice corrosion. As a result of intensive investigations on a method for reliably preventing the occurrence of crevice corrosion, the present inventors have found that the method of overlay welding a gap portion has the highest anticorrosion effect.

  That is, in the resistance welded portion and the joint portion by the caulking structure according to the present invention, overlay welding is performed, and then the above-described method for chemically removing the oxide scale is performed on the welded portion and the surrounding oxide scale forming portion. Do.

  In the build-up welding according to the present invention, either a ferritic stainless steel co-metal system or an austenitic stainless steel can be used for the welding rod.

  As a ferritic stainless steel welding rod, a general one can be used. However, when ferritic stainless steel is used, it is preferable to use austenitic stainless steel because it is inferior in toughness as compared with the case where austenitic stainless steel is used.

  Next, an austenitic stainless steel welding rod used for overlay welding according to the present invention will be described.

  Chromium requires 16% or more to ensure the corrosion resistance of the weld. However, the corrosion resistance of the welded portion improves with an increase in the chromium content in the weld metal, but if it exceeds 25%, the phase fraction of δ ferrite in the welded portion increases, causing deterioration of the toughness of the welded portion. Therefore, the upper limit is 25%.

  Nickel is an indispensable element for obtaining a γ structure, and requires addition of 8% or more. However, if it exceeds 16%, the phase fraction of δ ferrite is small, so that phosphorus or sulfur segregates at the grain boundaries and causes grain boundary cracking during welding cooling, so the upper limit is 16%.

  Manganese is also an effective element for selecting the γ structure, but if it exceeds 2%, the corrosion resistance is adversely affected, so 2% is made the upper limit.

  Molybdenum and silicon are not the elements to be actively added, but may be present as impurities, but the content of molybdenum is usually 0.2% or less and the content of silicon is 0.4 to 0.8%. There are many cases.

  Regarding the carbon and nitrogen contents, the carbon content is 0.03% or less, and the nitrogen content is 0.05% or less. When the content of carbon and nitrogen exceeds the above range, precipitation of chromium carbonitride occurs at the base material grain boundary, and the intergranular corrosion resistance is deteriorated. In particular, in order to balance both corrosion resistance and weld cracking, it is desirable that a value obtained by multiplying Cr equivalent and Ni equivalent (Cr equivalent × Ni equivalent) based on the following formula (1) exceeds 160.

Cr equivalent × Ni equivalent> 160 (1)
(However, Cr equivalent = Cr% + Mo% + 1.5Si%, Ni equivalent = Ni% + 0.5Mn% + 30C% + 30N%, Mo and Si are contained as inevitable impurities.)
The nickel-free chromium-containing steel of the present invention can be produced using either an electric furnace or hot metal. Since the steel of the present invention needs to reduce the carbon and nitrogen concentrations in the steel for the reasons described above, the secondary refining process is important in both the electric furnace and the hot metal, and the carbon and nitrogen in the steel. It is necessary to reduce the concentration sufficiently. The molten steel whose components have been adjusted in this way is usually continuously cast into a slab shape. The slab is hot-rolled in a temperature range of 1050 to 1200 ° C. after sufficiently soaking in a temperature range selected according to the steel type until a predetermined thickness is reached. Subsequently, it undergoes a solution heat treatment in a temperature range of 800 to 950 ° C., and is subjected to shot and pickling steps to obtain a product.

Here, examples of the present invention will be described, but the present invention is not limited to the conditions used in the examples.
Example 1
Test pieces of length 100 mm × width 50 mm × thickness 1.2 mm were prepared for steels 1 to 6 of the present invention , reference steels 1 and 5 and comparative steels 1 to 5 shown in Table 1. Next, TIG welding was performed on two test pieces of the same steel type while performing back shielding using an argon gas having a flow rate of 30 L / min, butting in the longitudinal direction.

  After welding, the welded part and the periphery of the welded part were pickled with a mixed solution of 10% by mass nitric acid aqueous solution and 3% by mass hydrofluoric acid aqueous solution to remove the oxide scale formed during welding. The pickling was performed until the oxidized scale could be considered to be removed by visual observation, that is, until the colored portion could be regarded as having a metallic luster. After pickling, it was washed with water and dried.

  Next, using the above-mentioned welded test piece, (1) immersion for 1 month in an aqueous solution having a chloride temperature of 100 mass ppm at a liquid temperature of 50 ° C. and pH 3, and (2) chlorinated at a liquid temperature of 50 ° C. and pH 5. Immersion for 1 month in a solution consisting of an aqueous phase and an oil phase with an ion concentration of 100 mass ppm, (3) Immersion for an month in an emulsion with a chloride temperature of 200 mass ppm at a liquid temperature of 40 ° C., pH 11; The immersion test was conducted under the following three conditions.

  The corrosion resistance of the base metal part and the welded part of the test piece after the immersion test was evaluated by visual observation. ◎: No red rust or stain was generated, ○: Very slight stain was generated, △: Clear stain was generated, × : Evaluated in four stages, apparent red rust generation.

Table 2 shows the results of the immersion test. The evaluations of the present invention steels 1 to 6 were ◎ or ◯ in any of the above three conditions, and showed excellent corrosion resistance in the base material and the welded portion, whereas the evaluations of the comparative steels 1 to 5 In all of the above three conditions, x or Δ, and red rust occurred in the welded part.

(Example 2)
Using the present invention steels 1 and 3 shown in Table 1, test pieces having the same shape as in Example 1 were produced. Next, two test pieces of the same steel type were subjected to seam welding by butting in the longitudinal direction. Further, austenitic stainless steel welding rods shown in Table 3 (welding rods 1 to 3 of the present invention, welding of comparative examples). Overlay welding was performed with the combinations shown in Table 4 using the rods 1 and 2).

  After welding, the welded portion and the periphery of the welded portion were pickled using the same mixed solution as in Example 1 to remove the oxide scale formed during welding. Whether or not the oxide scale could be removed was confirmed according to the same criteria as in Example 1, washed with water and dried after pickling.

  Next, using the welded test piece, an immersion test was performed under the same three conditions as in Example 1. In the same manner as in Example 1, the base material part of the test piece after the immersion test and the corrosion resistance of the welded part were used. Were observed and evaluated.

  Table 4 shows the results of the immersion test. Inventive Examples 1 to 3 using the inventive steel and the welding rod of the inventive method are ◎ or ◯ in any of the above three conditions, and show very good corrosion resistance, while the inventive steel and comparative examples Comparative Examples 1 to 3 using the welding rods of the examples were X or Δ in any of the above three conditions, and red rust occurred in the welded portions.

Claims (7)

A chromium-containing steel used for a container material for storing a water-based paint comprising an aqueous phase having a pH of 3 to 12 containing 0.01 to 200 ppm by mass of a halogen compound ion, wherein the steel is in% by mass,
Cr: 9 to 19% (excluding Cr: 9 to 11.2%)
N: 0.008% or more, C + N: 0.03% or less,
Al: 0.002 to 0.2%,
S: 0.01% or less,
In addition, Ti and Nb are contained alone or in combination, and when the C + N content is x (mass%), Ti content y (mass%) and Nb content z (mass) %), If contained alone,
8x ≦ y ≦ 0.6, 18x ≦ z ≦ 0.6,
And when it is contained in combination,
1 <(y / 8x) + (z / 18x) and y + z ≦ 0.6
And the balance is made of Fe and inevitable impurities, and contains chromium and steel for container materials.   The said chromium containing steel contains 0.005 mass% or less of Ca further, The chromium containing steel for container materials of Claim 1 characterized by the above-mentioned.   The said chromium containing steel contains 0.5-3 mass% of 1 type or 2 types of Mo and W further, The chromium containing steel for container materials of Claim 1 or 2 characterized by the above-mentioned.   After performing fusion welding to the chromium-containing steel for container material according to any one of claims 1 to 3 while performing backshielding using argon gas at a flow rate of 20 L / min or more, the fusion welded portion and A method for welding chromium-containing steel for container materials, characterized by chemically removing oxide scale formed around the surroundings.   After performing mechanical joining by resistance welding or caulking structure to the chromium-containing steel for container material according to any one of claims 1 to 3, overlay welding is performed on the welded part or joined part, and then A method for welding chromium-containing steel for container materials, characterized by chemically removing the build-up weld and the oxide scale formed around it. The build-up welding uses austenitic stainless steel for the welding rod, and the content of the welding rod is, by mass,
Cr: 16 to 25%,
Ni: 8 to 16%,
C: 0.03% or less,
N: 0.05% or less,
The Mn: 2.00% or less, the balance consists of Fe and inevitable impurities, and further Cr equivalent and Ni equivalent satisfy the following formula: Welding method.
Cr equivalent × Ni equivalent> 160
{However, Cr equivalent = Cr (mass%) + Mo (mass%) + 1.5 Si (mass%), Ni equivalent = Ni (mass%) + 0.5 Mn (mass%) + 30C (mass%) + 30N (mass%), Mo and Si are contained as inevitable impurities. }   A container material obtained by processing and forming the chromium-containing steel for container materials according to any one of claims 1 to 3.