KR20170054824A - But joint welding material - Google Patents

But joint welding material Download PDF

Info

Publication number
KR20170054824A
KR20170054824A KR1020150157461A KR20150157461A KR20170054824A KR 20170054824 A KR20170054824 A KR 20170054824A KR 1020150157461 A KR1020150157461 A KR 1020150157461A KR 20150157461 A KR20150157461 A KR 20150157461A KR 20170054824 A KR20170054824 A KR 20170054824A
Authority
KR
South Korea
Prior art keywords
welding
welded
chromium
horizontal posture
welding material
Prior art date
Application number
KR1020150157461A
Other languages
Korean (ko)
Inventor
김영주
김정현
이태영
조한진
허만주
Original Assignee
대우조선해양 주식회사
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 대우조선해양 주식회사 filed Critical 대우조선해양 주식회사
Priority to KR1020150157461A priority Critical patent/KR20170054824A/en
Publication of KR20170054824A publication Critical patent/KR20170054824A/en

Links

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
    • B23K35/36—Selection of non-metallic compositions, e.g. coatings, fluxes; Selection of soldering or welding materials, conjoint with selection of non-metallic compositions, both selections being of interest
    • 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
    • B23K35/02—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape
    • B23K35/0255—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape for use in welding
    • B23K35/0261—Rods, electrodes, wires
    • 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
    • B23K35/02—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape
    • B23K35/0255—Rods, electrodes, materials, or media, for use in soldering, welding, or cutting characterised by mechanical features, e.g. shape for use in welding
    • B23K35/0261—Rods, electrodes, wires
    • B23K35/0266—Rods, electrodes, wires flux-cored
    • 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
    • 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
    • B23K35/36—Selection of non-metallic compositions, e.g. coatings, fluxes; Selection of soldering or welding materials, conjoint with selection of non-metallic compositions, both selections being of interest
    • B23K35/362—Selection of compositions of fluxes

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Nonmetallic Welding Materials (AREA)

Abstract

A horizontal posture welded welding material is provided. The welding material contains carbon (C): 0.04 to 0.05% by weight, silicon (Si): 0% by weight. (Cu), nickel (Ni), chromium (Cr), chromium (Cr), and chromium (Cr) ), Molybdenum (Mo), and vanadium (V). In order to prevent the molten metal in the horizontal posture versus welded joint heat welding, the molten metal Melting slag generating component that prevents the weld bead from sagging at the same time as the viscosity of the weld bead increases.

Description

[0001] BUT JOINT WELDING MATERIAL [0002]

The present invention relates to a welding material for a welding apparatus of a horizontal butt joint, and more particularly, to a horizontal posture welding welding material configured to be capable of performing a large welding process for a welded joint formed in a horizontal posture at the time of manufacturing a ship.

Generally, a butt joint is welded by welding a facing welded base material, and it is often used when the steel plate is rolled.

When such butt welds are vertically butt-welded together in a horizontal butt joint, the upper and lower weld base materials usually face each other and the weld joints are in a beveled configuration. Then, the upper welding base material (1a) d is sloped on the improvement surface, and the lower welding base material is welded in a state in which the lower welding base material is improved at a right angle in the plane.

When the flux cored arc welding method using automatic equipment is applied to such a horizontal butt joint, the upper welding base material and the lower welding base material are arranged to have different gaps according to the degree of fabrication. (Root welding) is first performed on the back side of the surface to be welded to form a root portion.

When the welding is performed inside the improvement where the root portion is formed, the molten molten material precedes the welding arc due to the viscosity of the low molten molten material and the gravity acting on the molten molten material, and the arc is formed on the molten molten material. The arc formed on the molten metal is difficult to sufficiently penetrate the base metal, and defects such as fusion failure and slag inclusion frequently occur in the weld metal.

In the case of welding using a rutile type welding material and a metal type welding material or an EGW (Electro Gas Welding) material used in horizontal posture welding welding having these characteristics, Since the strength and elongation are low and the arc instability due to the molten metal advance, internal welding defect, and surface welding bead failure occur frequently, horizontal posture welding welding is impossible.

International Publication No. WO2014 / 129766 Korean Patent Publication No. 2013-0029624

It is an object of the present invention to provide a horizontal attitude welding welding material which improves the tensile strength and elongation of a welded portion and improves an internal weld defect and a surface weld bead defect in horizontal posture to welding welding.

According to one embodiment of the present invention, the carbon material is 0.04 to 0.05%, the silicon (Si): 0. (Cu), nickel (Ni), chromium (Cr), chromium (Cr), and chromium (Cr) ), Molybdenum (Mo), and vanadium (V), and the molten metal alloy component includes at least one element selected from the group consisting of molten There is provided a horizontal posture welded welding material comprising a high melting point slag product that prevents sagging of the weld bead at the same time as the viscosity of the molten material increases.

Wherein the copper (Cu) is 0.01 to 0.02%, the nickel (Ni) is 0.01%, the chromium (Cr) is 0.02 to 0.03%, the molybdenum (Mo) is 0.004 to 0.01% 0.01 to 0.02%.

The high-melting-point slag product is a titanium dioxide (TiO 2), silicon dioxide (SiO 2), sodium (NaO), potassium oxide (K 2 O), zirconium dioxide (ZrO 2), aluminum oxide (Al 2 0 3) And at least one kind selected from the group consisting of:

The elongation of the weld metal using the welding material may be 22% or more and the impact test value may be 35J or more.

The wire may be a flux cored wire.

In the horizontal posture versus welded welding using the welding material according to the present invention, it is possible to improve the tensile strength and elongation of the welded portion, and to improve the internal welded defect and the surface welded bead failure.

Hereinafter, embodiments of the present invention will be described in detail. It will be apparent to those skilled in the art that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, It is provided to let you know.

According to one aspect of the present invention, the welding material includes 0.04 to 0.05% by weight of carbon (C), 0% by weight of silicon (Si) (Cu), nickel (Ni), chromium (Cr), chromium (Cr), and chromium (Cr) ), Molybdenum (Mo), and vanadium (V). In order to prevent the molten metal in the horizontal posture versus welded joint heat welding, the molten metal Melting slag generating component that prevents the weld bead from sagging at the same time as the viscosity of the weld bead increases.

(Cu) is 0.01 to 0.02%, nickel (Ni) is 0.01%, chromium (Cr) is 0.02 to 0.03%, molybdenum (Mo) is 0.004 to 0.01%, vanadium (V) is 0.01 to 0.02% .

The high-melting-point slag product is a titanium dioxide (TiO 2), silicon dioxide (SiO 2), sodium (NaO), potassium oxide (K 2 O), zirconium dioxide (ZrO 2), aluminum oxide (Al 2 0 3) And at least one kind selected from the group consisting of:

Hereinafter, the deposited metal alloy component of the welding material of the present invention will be described in more detail.

Carbon (C): 0.04 to 0.05%

The carbon (C) is an element for securing the strength of the welding portion and securing the welding hardenability, and it is preferable that the carbon (C) is added in an amount of 0.04 to 0.05%. If the content is excessive, the weldability is greatly reduced and the occurrence of low-temperature cracks is promoted.

Silicon (Si): 0.49 to 0.57%

Silicon (Si) is an element to be added for the deoxidizing effect. When the content is insufficient, the deoxidizing effect in the welded joint is insufficient and the fluidity of the welded joint deteriorates. When the content of the welded joint is excessive, Thereby lowering the impact resistance at low temperature and affecting the low temperature crack susceptibility of the weld.

Manganese (Mn): 1.56 to 1.75%

Manganese (Mn) is an element useful for deoxidation and strength enhancement in the steel, which is advantageous in securing strength and toughness by solid-solution strengthening the matrix by forming a substitutional solid solution in the matrix. If the content is excessive, the hardenability of the weld portion is increased to deteriorate the impact toughness of the weld portion.

Phosphorus (P): 0.011 to 0.013

Since phosphorus (P) is an impurity element promoting high-temperature cracking during welding, it is preferable to control the phosphorus to a low level as much as possible.

Sulfur (S): 0.006 to 0.011%

Since sulfur (S) is an impurity element promoting high-temperature cracking during welding together with phosphorus (P), it is preferable to control the sulfur content to as low as possible. If the content is excessive, a low melting point compound such as FeS may be formed to cause high-temperature cracking. Therefore, it is preferable to control at an appropriate content for preventing cracking at a high temperature.

Copper (Cu): 0.01 to 0.02%

Copper (Cu) is an element effective in improving strength and toughness due to solubility enhancement by being dissolved in a matrix. If the content is too low, the effect can not be obtained. If the content is excessive, if the toughness of the weld portion is increased to lower the toughness, the high temperature crack in the weld portion can be promoted.

Nickel (Ni): 0.01%:

Nickel (Ni) is an element effective for enhancing the strength and toughness of a base by solid solution strengthening. If the content is increased, there is a fear that the incombustibility of the steel is increased and the high-temperature cracking of the welded portion is promoted.

Cr (Cr): 0.02 to 0.03%

Chromium (Cr) increases the incombustibility and is an effective element for improving the strength. If the content is too low, such effect can not be obtained. If the content is excessive, toughness of the welded portion may be deteriorated.

Molybdenum (Mo) 0.004 to 0.01%:

Molybdenum (Mo) increases the incombustibility and is an effective element for improving the strength and the content thereof is insufficient. Such effects can not be obtained. If the content is excessive, the strength of the high strength weld metal may be affected.

Vanadium (V) 0.01 to 0.02%:

Vanadium (V) is a component that is incorporated in steel to delay the state velocity of ferrite and bainite to facilitate the formation of martensite. It also acts as a main element causing strengthening of the solution and strengthening of the precipitation. If the content is excessive, the effect becomes saturated, toughness and weldability may be deteriorated, and the cost of manufacturing the steel may increase.

Titanium dioxide (TiO 2 ) and zirconium dioxide (ZrO 2 )

Titanium dioxide (TiO 2 ) and zirconium dioxide (ZrO 2 ) are effective components for ensuring arc stability and slag fluidity. If the content of such oxides is insufficient, the slag fluidity becomes unstable and the weld bead shape becomes poor. The slag fluidity can be secured, but the occurrence of spatter is increased and the weldability and bead shape are poor.

Sodium oxide (NaO) and potassium oxide (K 2 O)

Sodium oxide (NaO) and potassium oxide (K 2 O) reduce the ionization potential of the arc during welding to facilitate arc generation and maintain a stable arc during welding. If the content is excessive, high fume may occur due to high vapor pressure, and the slag viscosity is excessively reduced to form an unstable inner bead.

Silicon dioxide (SiO 2)

As dioxide components of silicon (SiO 2) may increase the slag viscosity, in the primary slag in welding materials titanium dioxide (TiO 2) the viscosity, and the effect is insignificant, and the content of the viscosity is excessively increased when many such inclusions remaining defect and There is a risk of cracking due to an increase in silicon (Si) content of the deposited metal.

Zirconium dioxide (ZrO 2 )

Zirconium dioxide (ZrO 2 ) is a component that increases the melting point of slag because of its high temperature melting point. If the content is excessive, an unmelted spike is formed in the arc.

Aluminum oxide (Al 2 O 3 )

Aluminum oxide (Al 2 O 3 ) is a component for improving the slag viscosity and is preferably added for the purpose of good bead formation and molten metal protection, but in consideration of low specific gravity.

In the present invention, in order to improve the tensile strength and elongation ratio of the welded portion by adjusting the alloy component proportion of the weld metal in the horizontal posture versus welding, and to reduce occurrence of internal weld defect and surface weld bead failure at the time of welding, By controlling the kinds of the components and the amount of the additives, it was intended to obtain a welded portion having excellent mechanical properties and to improve the weldability.

Hereinafter, the present invention will be described more specifically by way of examples.

A welding material having a composition of the deposited metal as shown in the following Table 1, for example, a flux cored welding wire, was prepared.

division C Si Mn P S Ni Cr Mo Cu V Inventory 1 0.052 0.548 1.590 0.010 0.006 0.011 0.023 0.003 0.009 0.015 Inventory 2 0.053 0.501 1.520 0.011 0.007 0.013 0.021 0.003 0.008 0.015 Inventory 3 0.055 0.490 1.587 0.010 0.008 0.018 0.030 0.004 0.011 0.015 Honorable 4 0.048 0.467 1.475 0.014 0.008 0.012 0.028 0.003 0.009 0.015 Inventory 5 0.056 0.521 1.612 0.012 0.006 0.015 0.028 0.004 0.007 0.015 Inventory 6 0.043 0.493 1.573 0.012 0.006 0.017 0.030 0.004 0.009 0.013

Then, welding was performed using each of the above-mentioned welding materials, and the mechanical properties and welding conditions (surface bead, backside bead) and arc stability of welded portions formed after welding were evaluated. The welding conditions are shown in Table 2 below, and the mechanical properties of the welds are shown in Table 3 below.

Using the welding materials of Inventive Examples 1, 2 and 5, 12-pass CO 2 welding was carried out on a welding object having a welding groove of 45 ° and a root gap of 12 mm under the conditions of a welding current of 310 A and a voltage of 30 V.

On the other hand, in the case of Inventive example 6, 4-pass CO 2 welding was performed on a welding object having a welding groove of 45 ° and a root gap of 5 mm under the conditions of a welding current of 400 A and a voltage of 40 V.

In the case of Inventive Examples 3 and 4, mechanical properties were not evaluated because welding workability was improved.

In Inventive Example 2 , the arc stabilizer and the slag component in Inventive Example 1 were slightly reduced in the amount of the remaining slag components except for TiO 2 .

Inventive Example 3 increased the high melting point slag component to prevent sagging in high heat input.

In Inventive Example 4, an alloy component such as aluminum (Al) was adjusted to make the bead shape into a conical shape.

Example 5 further increases the high melting point slag component in Inventive Example 3 and adds the high melting point slag ingredient that was not used in Inventive Example 3.

Inventive Example 6 adjusted the carbon (C) and manganese (Mn) contents in Inventive Example 5 to improve properties (elongation).

division Surface bead Backside bead Arc stability Remarks Inventory 1 Bad Bad Good Inventory 2 Bad Bad Good Edge curl disappears. Bead rough phenomenon and separation are insufficient Inventory 3 Bad Bad Good Improvement in peelability, spatter at one time level, good fluidity Honorable 4 Bad Bad Good Poor peeling, double bead occurrence, bead rough appearance Inventory 5 Good Good Good Good peeling, reduced spatter Inventory 6 Good Good Good Improved strength and elongation at high heat welding

division Tensile test Charpy V-Notch impact test value [J] Yield strength
[N / mm 2 ] The tensile strength
N / mm 2 Elongation
[%] -20 ° C -30 ° C Inventory 1 493.2 551.5 32.5 100.3 61.7 Inventory 2 609.7 680.1 25.4 49.3 28.7 Inventory 3 - - - - - Honorable 4 - - - - - Inventory 5 568.2 648.5 27.4 54.0 37.3 Inventory 6 484.1 592.9 26.2 49.0 32.7

As shown in Tables 2 and 3, it was confirmed that, in the case of Examples 5 and 6 of the present invention, good welding characteristics and mechanical properties can be secured.

Next, the tensile test and the impact test of the weld metal by the welding material of Inventive Example 6 of the present invention were carried out to obtain tensile test results and impact test results as shown in Tables 4 and 5 below.

One. Tensile test result

division size
[?, mm] Cross section [mm 2 ] Gauge distance
[mm] Yield strength
[N / mm 2 ] The tensile strength
[N / mm 2 ] Elongation
[%] Section shrinkage ratio
[%] Inventory 6 9.96 77.91 50 519.3 604.7 25.24 44.05 Inventory 6 9.94 77.60 50 498.8 590.0 26.92 59.83

2. Impact test result (20 ℃) [J]

Specimen Number One 2 3 4 5 6 Average Inventory 6 112 76 83 84 93 87 89

As shown in Tables 4 and 5, when the specimens were subjected to the tensile test value impact test using the fused metal of the welding material of Inventive example 6 of the present invention, for example, the welded part, it was found that good elongation (22% The impact test result (34J or more) was obtained.

Although the present invention has been described with reference to the preferred embodiments described above, the present invention is not limited thereto but is limited by the following claims. Accordingly, those skilled in the art will appreciate that various modifications and changes may be made thereto without departing from the spirit of the following claims.

Claims (5)

(C): 0.04 to 0.05% by weight, silicon (Si): 0. (P): 0.011 to 0.013, sulfur (S): 0.006 to 0.011%, and unavoidable impurities,
And at least one member selected from the group consisting of copper (Cu), nickel (Ni), chromium (Cr), molybdenum (Mo) and vanadium (V)
Horizontal posture versus welded joint welding Horizontal posture welded welding material containing high melting point slag generating component which prevents weld bead sagging simultaneously with increase of viscosity of molten metal to prevent molten metal lead in welding. The method according to claim 1, wherein the copper (Cu) is 0.01 to 0.02%, the nickel (Ni) is 0.01%, the chromium (Cr) is 0.02 to 0.03%, the molybdenum (Mo) Wherein the vanadium (V) comprises 0.01 to 0.02%. According to claim 1, wherein said high-melting-point slag generation component is titanium dioxide (TiO 2), silicon dioxide (SiO 2), sodium (NaO), potassium oxide (K 2 O), zirconium dioxide (ZrO 2), aluminum oxide (Al 2 O 3 ) in the horizontal posture versus welding position. The welding material according to claim 1, wherein the welded portion using the wire has an impact test value of 35J or more and an elongation percentage of 22% or more. The welding post according to claim 1, wherein the wire is a positive cored wire.
KR1020150157461A 2015-11-10 2015-11-10 But joint welding material KR20170054824A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
KR1020150157461A KR20170054824A (en) 2015-11-10 2015-11-10 But joint welding material

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
KR1020150157461A KR20170054824A (en) 2015-11-10 2015-11-10 But joint welding material

Publications (1)

Publication Number Publication Date
KR20170054824A true KR20170054824A (en) 2017-05-18

Family

ID=59048975

Family Applications (1)

Application Number Title Priority Date Filing Date
KR1020150157461A KR20170054824A (en) 2015-11-10 2015-11-10 But joint welding material

Country Status (1)

Country Link
KR (1) KR20170054824A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
PL424391A1 (en) * 2018-01-26 2019-07-29 Politechnika Śląska Cast iron powder core, preferably for producing layers resistant to corrosion and abrasive wear

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
PL424391A1 (en) * 2018-01-26 2019-07-29 Politechnika Śląska Cast iron powder core, preferably for producing layers resistant to corrosion and abrasive wear

Similar Documents

Publication Publication Date Title
KR101443480B1 (en) Ni-based alloy welding metal, ni-based alloy-coated arc welding rod
KR102208029B1 (en) Electroslag welding wire, electroslag welding flux and weld joints
JP6927304B2 (en) Gas shield arc welding method for steel sheets
JP4303655B2 (en) Welding method for galvanized steel sheets with excellent corrosion resistance and zinc embrittlement crack resistance
JP2019025524A (en) Flux-cored wire for gas-shielded arc welding, and manufacturing method of welded joint
JP6201803B2 (en) Submerged arc welds with excellent low temperature toughness
KR101600174B1 (en) Flux cored wire for gas shielded arc welding
KR20180016569A (en) Flux cored wire for gas shield arc welding
JPWO2019186701A1 (en) Ni-based alloy wire for submerged arc welding and method for manufacturing welded joint
JP5968934B2 (en) Welding method of galvanized steel sheet
CN112621016B (en) Welding material, weld metal, and electroslag welding method
KR102032106B1 (en) Vertical direction narrow gas shielded arc welding method
JP6119948B1 (en) Vertical narrow groove gas shielded arc welding method
KR101168162B1 (en) Submerged arc welding flux for thick steel plate welding
JP2022102850A (en) SOLID WIRE FOR GAS SHIELD ARC WELDING USED FOR WELD OF LOW Si STEEL, JOINTING METHOD OF LOW Si STEEL, AND REPAIR METHOD OF LOW Si STEEL
JP2019025525A (en) Flux-cored wire for gas-shielded arc welding, and manufacturing method of welded joint
KR20170054824A (en) But joint welding material
JP6776798B2 (en) Multi-layer submerged arc welding method
KR102150974B1 (en) Tandem gas shielded arc welding wire having good low temperature toughness
KR20170082304A (en) Titania Based Flux Cored Wire of Gas Shielded Arc Welding for excellent hot crack resistance according to high heat input
JP2022105363A (en) Welded joint, and automobile member
KR102051960B1 (en) Tandem gas shielded arc welding wire
KR102088500B1 (en) Titania Based Flux Cored Wire of Gas Shielded Arc Welding for excellent impact value in post weld heat treatment
KR101264606B1 (en) Gas shielded arc welding titania based flux cored wire having excellent crack resistance
JP7327667B2 (en) Gas-shielded arc welding method, welded joint, and method for manufacturing the welded joint

Legal Events

Date Code Title Description
A201 Request for examination
E601 Decision to refuse application