CN1995432B - Welding joint steel plated with excellent low-temperature flexibility - Google Patents
Welding joint steel plated with excellent low-temperature flexibility Download PDFInfo
- Publication number
- CN1995432B CN1995432B CN2005101357835A CN200510135783A CN1995432B CN 1995432 B CN1995432 B CN 1995432B CN 2005101357835 A CN2005101357835 A CN 2005101357835A CN 200510135783 A CN200510135783 A CN 200510135783A CN 1995432 B CN1995432 B CN 1995432B
- Authority
- CN
- China
- Prior art keywords
- contain
- steel plate
- welding
- low
- heat input
- Prior art date
- Legal status (The legal status 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 status listed.)
- Active
Links
Abstract
The invention discloses a steel board, which comprises the following parts: 0.005-0.10% C, less than 0.7% Si, 0.5-2% Mn, less than 0.1% Al, 0.005-0.03% Ti and 0.001-0.01% N, wherein the microscopic tissue is composed of ferrite and other tissues with even density as 4 times as carbon density in the steel board.
Description
Technical field
The present invention relates near the excellent steel plate (refering in particular to slab) of low-temperature flexibility of a kind of welded-joint (welding line when big heat input is welded, two phase region heating parts when little heat input is welded etc.).
Background technology
Nowadays, the steel plate that low-temperature flexibility is excellent in each field by widespread demand.For example, with in the container etc., for the liquefaction of gas, and use under the low temperature about-60 ℃ is so also requiring its toughness good under the low temperature at the low temperature of stock solution liquefied oil gas (LPG) and liquefaction ammonium.Particularly because welding joint is changed by the microtexture due to the welding heat and causes toughness to be easy to deterioration, so the excellent steel plate of the low-temperature flexibility of demand welding joint consumingly.
For example, carry out improve (spy opens clear 54-19412 communique etc.) by the chemical composition of adjustment steel plate to the low-temperature flexibility of welding point.Promptly open in the clear 54-19412 communique the spy; It is conceived to if generate the island martensite body at welding point; Then, this island martensite body becomes mutually the starting point of destruction because being the hard that concentrated suitable C; So having proposed to reduce this island martensite body is purpose, and the C content of reduction steel (mother metal).But, produce outside the low-temperature flexibility effect, also further require the improvement of low-temperature flexibility in adjustment through chemical ingredients.For example, the time be heated to about 1400 ℃ high-temperature area (the heat affecting part during big heat input welding (below be sometimes referred to as HAZ) etc. in welding) in, make the low-temperature flexibility deterioration because of thickization of crystal grain, so require further to improve low-temperature flexibility.
Therefore open in the flat 9-165656 communique the spy, be suppressed at thickization of the crystal grain of HAZ by making precipitate (TiN etc.) fine dispersion.But, when carrying out big heat input welding, compare near the zone that forms high temperature (more than 1400 ℃) (for example, the welding line when big heat welding input etc.) with said HAZ portion.And when carrying out little heat input welding, also have and compare the zone of standing cryogenic thermal process with big heat input welded H AZ portion (for example, near the welding line during little heat input.In this zone, be heated to two phase regions between Ac1 point and the Ac3 point (below, be called two phase region heating parts)).Near welding line with big heat input welding, because the precipitate solid solution of TiN etc., so can't expect to suppress the effect of thickization of crystal grain.Also have, in two phase region heating parts, form ferritic and austenitic equilibrium state, C from then on ferritic is transferred in the austenite, and C concentrates in austenite, has consequently generated island martensite body (so phenomenon is known as two phase region embrittlement).Fine precipitate prevents that to two phase region embrittlement effect is also very little.
Summary of the invention
The present invention is conceived to this type of above-mentioned situation, and its purpose is, proposes near the excellent steel plate of low-temperature flexibility of a kind of welded-joint (welding line when big heat input is welded, two phase region heating parts when little heat input is welded etc.).
Present inventors in order to solve the said problem result of research with keen determination repeatedly, draw following understanding and accomplish the present invention; Promptly be conceived to: the island martensite body that becomes the reason of embrittlement; Because the every part from steel (mother metal) does not generate equably, but generate, so if microsegregation portion is controlled energetically from the microsegregation portion of C; Then can control the generation of island martensite body more to heavens, thereby can further improve the low-temperature flexibility of welding joint.
Promptly; The steel plate that the low-temperature flexibility of welding joint of the present invention is excellent wherein, has following chemical constitution: establish the C:0.005～0.10% (meaning of quality %; As follows), (not containing 0%), Mn:0.5～2% below the Si:0.7%, (not containing 0%), Ti:0.010～0.03% below the Al:0.1%, and N:0.001～0.01%; Remainder is Fe and unavoidable impurities, and microtexture is by other the organizational composition beyond ferritic and this ferritic, the average carbon density in these other the tissue; With respect to the carbon concentration in the steel plate integral body is below 3.0 times, and the area occupation ratio of its hetero-organization beyond the ferritic is 5～20%.
Said steel plate also can contain as follows: (not containing 0%) below (not containing 0%), the Nb:0.05% below (not containing 0%), the V:0.1% below (not containing 0%), the Mo:0.5% below (not containing 0%), the Cr:0.5% below (not containing 0%), the Cu:0.5% below (not containing 0%), the Ni:0.5% below (not containing 0%), the B:0.005% below (not containing 0%), the REM:0.01% below (not containing 0%), the Mg:0.005% below (not containing 0%), the Ca:0.005% below the Zr:0.05% etc. in addition.
Steel plate of the present invention, because not only form the chemical ingredients of defined, the average carbon density in the tissue of other beyond the ferritic is below 4 times with respect to the carbon concentration in steel plate integral body, so the low-temperature flexibility of welding joint is excellent.
Embodiment
Steel plate of the present invention, its microtexture is made up of other the tissue (to call second in the following text mutually) beyond ferritic and this ferritic.As second phase, can give an example for example bainite, perlite, island martensite body etc.And second can be one tissue mutually, but also can be by a plurality of organizational compositions.Perlite normally.
And in steel plate of the present invention, with respect to the carbon concentration in steel plate whole (mother metal), said second the average carbon density (second during by a plurality of organizational composition, being the average weighted meaning) in mutually is suppressed extremely lowly.Second contains the microsegregation portion that when welding, makes the C of island martensite body generation in fact the most easily mutually, suppresses extremely lowly through the average carbon density with this second phase, can control the generation of island martensite body extremely to heavens.Therefore good near the low-temperature flexibility of welded-joint (welding line when big heat input is welded, two phase region heating parts when little heat is imported welding etc.).Specifically, second the average carbon density in mutually, the carbon concentration with respect to steel plate whole (mother metal) below 4 times, is preferably below 3.5 times, further is preferably below 3.0 times, most preferably is below 2.5 times.Also have, the lower limit of said average carbon density is not done restriction especially, but usually more than 0.5 times about (for example being more than 1.0 times, to be preferably more than 1.5 times).
The area occupation ratio of the 2nd phase is about 1～30% for example, is preferably about 5～20% further preferred about 7～15%.
And steel plate of the present invention; Contain: (not containing 0%), Ti:0.005～0.03% below (not containing 0%), Mn:0.5～2%, the Al:0.1% below C:0.005～0.10% (meaning of quality %, as follows), Si:0.7%, and N:0.001～0.01%.
The qualification of each composition the reasons are as follows said.
C：
C makes the low-temperature flexibility deterioration of welded-joint as the generation reason of island martensite body.Therefore, C is made as below 0.10%, is preferably below 0.09%, further is preferably below 0.08%.But if C is very few, then the intensity of steel plate too reduces.Therefore, C is made as more than 0.005%, is preferably more than 0.01%, further is preferably more than 0.03%.
Si：
Si makes the low-temperature flexibility deterioration of welded-joint if the excessive island martensite body that then makes increases.Therefore, Si is made as below 0.7%, is preferably below 0.5%, further is preferably below 0.3%, most preferably below 0.24%.And, because Si is used for the deoxidation of molten steel, so must residue in the steel.And also can improve the intensity of steel plate effectively.Si is made as more than 0.10%, is preferably more than 0.05%, also can further be preferably more than 0.15%.
Mn：
Mn is to improving hardenability, and the intensity that improves steel plate is effective.Therefore, Mn is made as more than 0.5%, is preferably more than 0.7%, further is preferably more than 1.0%.But,, the island martensite body is increased, thereby make the low-temperature flexibility deterioration of welded-joint if Mn is excessive.Therefore, Mn is made as below 2%, is preferably below 1.8%, further is preferably below 1.6%.
Al：
If Al is excessive, then the toughness deterioration of mother metal.Therefore, Al is made as below 0.1%, is preferably below 0.08%, further is preferably below 0.06%.On the other hand, use as reductor because Al is many, so be the element that in the adjustment process of molten steel, must sneak into.And, be precipitate because Al forms AlN, so the HAZ toughness can improve big heat input welding effectively the time.When making the HAZ flexible improve effect to bring into play effectively through Al, recommend Al for example to be made as more than 0.01%, be preferably more than 0.02%.
Ti：
It is precipitate that Ti forms TiN, the HAZ toughness in the time of can effectively improving big heat input welding.Therefore, Ti is made as more than 0.005%, is preferably more than 0.007%, further is preferably more than 0.010%.But, if Ti is excessive, the toughness deterioration of mother metal then.Therefore, Ti is made as below 0.03%, is preferably below 0.025%, further is preferably below 0.020%.
N：
The element of N and Ti and Al etc. forms nitride, the HAZ toughness in the time of can improving big heat input welding effectively.Therefore, N is made as more than 0.001%, is preferably more than 0.002%, further is preferably more than 0.003%.On the other hand, if N is excessive, then make the toughness deterioration of mother metal.Therefore, N is made as below 0.01%, is preferably below 0.008%, further is preferably below 0.006%.
Steel plate of the present invention; Other the element etc. that also can contain as required and append beyond must element said, for example: precipitate forming element " (not containing 0%) below (not containing 0%), the Mg:0.005% below (not containing 0%), the Ca:0.005% below the Zr:0.05%, and (not containing 0%) below the REM:0.01% etc. "; Toughness improves element " (not containing 0%) below the B:0.005%, Ni:0.5% following (not containing 0%) etc. "; Intensity improves element " (not containing 0%) below (not containing 0%), the Mo:0.5% below (not containing 0%), the Cr:0.5%, V:0.1% following (not containing 0%), (not containing 0%) below the Nb:0.05% etc. below the Cu:0.5% ".
Precipitate forming element: Zr, Ca, Mg, REM etc.
The formation nitride that Zr and said Ti are same, the HAZ toughness in the time of can improving big heat input welding effectively.The lower limit of the addition of Zr limits especially, but when actively expecting said action effect, is recommended as, and for example, is made as more than 0.0003%, is preferably more than 0.0005%, further is preferably more than 0.0010%.On the other hand, if Zr is excessive, then cause the low of cleanliness.Therefore, Zr is made as below 0.05%, is preferably below 0.005%, further is preferably below 0.003%.
Ca, Mg, and REM (rare earth element) form oxide compound, sulfide, oxysulfide etc., can prevent thickization of the crystal grain of HAZ effectively.And, also effective to the anisotropy that alleviates mother metal.Ca, Mg, and the lower limit of the addition of REM do not do special qualification; But when actively expecting said action effect; Be recommended as, for example, Ca is made as more than 0.0005% and (is preferably more than 0.0010%); Mg is made as more than 0.0005% and (is preferably more than 0.0010%), and REM is made as 0.0005% (being preferably more than 0.0010%).On the other hand, if this Ca, Mg, and the excessive then cleanliness of REM low.Therefore, Ca is made as below 0.005% and (is preferably below 0.003%), and Mg is made as below 0.005% and (is preferably below 0.003%), and REM is made as below 0.01% and (is preferably below 0.005%, most preferably below 0.003%).
Above-mentioned precipitate forming element can add separately, also can organize compound more and adds.
Toughness improves element: B, Ni etc.
B generates BN, and is fixing to the deleterious solid solution N of HAZ by it, has the effect of the generation of control grain boundary ferrite.The lower limit of the addition of B is not done special qualification, but when actively expecting said action effect, is recommended as, and for example is made as more than 0.0003%, is preferably more than 0.0005%, further is preferably more than 0.0010%.On the other hand, if the excessive then big heat input welded H AZ toughness deterioration of B.Therefore, B is made as below 0.005%, is preferably below 0.004%, further is preferably below 0.003%.
Ni can make toughness improve effectively.The lower limit of the addition of Ni is not done special qualification, but when actively expecting said action effect, is recommended as, and for example, is made as more than 0.01%, is preferably more than 0.05%, further is preferably more than 0.1%.On the other hand, then be easy to take place pit if Ni is excessive.Therefore, Ni is made as below 0.5%, is preferably below 0.4%.
Above-mentioned toughness improves element, can add separately, also can organize compound more and adds.
Intensity improves element: Cu, Cr, Mo, V, Nb etc.
Cu is the intensity rising effective elements to solution strengthening and precipitation strength.The lower limit of the addition of Cu is not done special qualification, but when actively expecting said action effect, for example, is made as more than 0.01%, is preferably more than 0.05%, further is preferably more than 0.10%.On the other hand, if the excessive then hot workability of Cu deterioration, crackle is easy to get into surface of steel plate.Therefore, Cu is made as below 0.5%, is preferably below 0.4%, further is preferably below 0.3%.
Cr and Mo are arbitrary all effective aspect the intensity that promotes mother metal.The lower limit of the addition of Cr and Mo is not done special qualification, but when actively expecting said action effect, is recommended as, and Cr for example is made as more than 0.05% and (is preferably more than 0.10%), and Mo for example is made as more than 0.01% and (is preferably more than 0.05%).On the other hand, if Cr and Mo are excessive, then be easy to make big heat input welded H AZ toughness deterioration.Therefore, Cr is made as below 0.5% and (is preferably below 0.3%), and Mo is made as below 0.5% and (is preferably below 0.3%).
V and Nb are arbitrary all to be elements that intensity is risen.The lower limit of the addition of V and Nb is not done special qualification; But when actively expecting said action effect, be recommended as, V for example is made as more than 0.005% and (is preferably more than 0.010%; Further preferred more than 0.02%), Nb for example is made as more than 0.001% and (is preferably more than 0.005%).On the other hand, if V and Nb are excessive, then side is easy to make big heat input welded H AZ toughness deterioration.Therefore, V is made as below 0.1% and (is preferably below 0.07%, further preferred below 0.05%), and Nb is made as below 0.05% and (is preferably below 0.035%, further preferred below 0.02%).
Above-mentioned intensity improves element, can add separately, also can organize compound more and adds.
Remainder can be Fe and unavoidable impurities.And as unavoidable impurities, P and S etc. for example can give an example.This P and S can reduce energetically.For example, P can be made as below 0.02% and (not contain 0%).If the excessive then deteriorated weldability of P.Preferred P is below 0.015%, most preferably below 0.013%.Also have, P also can be made as more than 0.001% about (hold is not more than 0.005%).
And S also can be made as below 0.01% and (not contain 0%).If S is excessive, then sulfide-based inclusion increases, and the anti-hydrogen induced cracking of steel plate is easy to produce.Preferred S below 0.007%, is preferably below 0.005% especially.And S also can be for about (being in particular more than 0.0005%) more than 0.0001%.
The present invention is of value in so-called slab application.Thickness of slab is for example for about 7mm above (being preferably more than the 10mm).Also have, the upper limit of thickness of slab is not done special qualification, but is generally about 50mm following (being in particular below the 30mm).
The steel plate that the preferred tensile strength of the present invention is excellent, for example for 350MPa above about (be preferably 400MPa above about).Also have, the upper limit of tensile strength is not done special qualification, but is generally about 650MPa following (being in particular below the 610MPa).
Steel plate of the present invention can be made according to following mode: the steel billet that will be adjusted into predetermined component is heated to about 900～1200 ℃ of temperature, carries out hot rolling (rolling outlet temperature is 700～850 ℃) afterwards, to cool off with comparing extremely hastily usually.If cooling hastily then can prevent the concentrating second phase at rolling back C.
Embodiment
Below; Enumerate embodiment the present invention is described more particularly, but the present invention does not receive the restriction of following embodiment, in all scopes that obtains meeting the described aim in front and back; Certainly can carry out the appropriateness change, it all is contained in the scope of technology of the present invention.
Next, to doing following evaluation with the resulting steel plate of following embodiment.
" the C concentration of second phase "
Cut out with the parallel section of rolling direction and grind in the position of degree of depth t/4 (t is the thickness of steel plate).With X-ray microanalysis device (EPMA: NEC's system " JCMA-7331 ") analyze this section (acceleration voltage: 15kV, multiplying power: 1000 times, microscope apparent field diameter: 10), try to achieve second the C concentration (quality %) in mutually in view of the above.
" near the low-temperature joint toughness the welding line when big heat input is welded "
With Heating temperature: 1400 ℃, 800～500 ℃ cooling time (Tc): steel plate is handled in 100 seconds thermal cycling, and the pendulum that is determined at temperature-60 ℃ absorbs energy (V groove).And said thermal cycling is envisioned near the thermal cycling the welding line of the FAB welding (FAB is the registered trademark of Kobe Steel Ltd.) of welding heat input 8kJ/mm.
" low-temperature joint toughness of two phase region heating parts when little heat input is welded "
With Heating temperature: 1400 ℃, 800～500 ℃ cooling time (Tc): 15 seconds thermal cycling is handled after the steel plate, and with Heating temperature: 800 ℃, 800～500 ℃ cooling time (Tc): steel plate is handled in 15 seconds thermal cycling.The pendulum that then is determined at temperature-60 ℃ absorbs energy (V groove).And said thermal cycling is envisioned for the CO at welding heat input 2kJ/mm
2In the welding, near two phase region heating parts the welding line that is considered to embrittlement.In above-mentioned two phase region heating parts, be easy to apply aforesaid dual thermal cycling.
Embodiment 1
To steel billet (the steel grade symbol: A that contains C:0.08%, Si:0.15%, Mn:1.50%, P:0.009%, S:0.002%, Al:0.038%, Ti:0.014%, N:0.0046%; Remainder is Fe and unavoidable impurities), be rolling to the thickness of slab of regulation with the various condition shown in the below table 1.
Evaluation result by the resulting steel plate of below table 1 expression.
Table 1
Can know from table 1, at the example of No.7, because second the excessive concentration of C in mutually, so near the low-temperature joint toughness the welding line when big heat input welding is poor.In the example of No.1～6, because second the C concentration in mutually is suitable, so near the low-temperature joint toughness the welding line when big heat input welding is excellent with respect to this.
Embodiment 2
The steel (steel grade A) of the composition that melting and embodiment 1 are same and the steel of the composition shown in the below table 2 are rolling to the thickness of slab of regulation with the various condition shown in the below table 3.
Evaluation result by the resulting steel plate of below table 3 expressions.
Can know from table 2 and table 3; In the example of No.17～21; Because second the excessive concentration of C in mutually, so near the low-temperature joint toughness the welding line when big heat input welding is poor, and the low-temperature flexibility of two phase region heating parts during little heat input welding is also poor.With respect to this, in the example of No.8～16 because second the C concentration in mutually is suitable, thus near the welding line when big heat input welding and the low-temperature flexibility of two phase region heating parts during little heat input welding excellent.
Steel plate of the present invention is excellent near the low-temperature flexibility of welding joint (welding line when big heat input is welded, two phase region heating parts when little heat input is welded etc.).Therefore, require the various steel plate of low-temperature flexibility can effectively utilize in, for example, the low temperature that is used in stock solution liquefied oil gas (LPG) and liquefaction ammonium is with the steel plate of container etc.
Claims (4)
1. a steel plate is characterized in that,
Have by below the chemical constitution that constitutes as follows: C:0.005～0.10%, Si:0.7% and do not contain 0%, Mn:0.5～2%, below the Al:0.1% and do not contain 0%, Ti:0.010～0.03%, and N:0.001～0.01%, remainder is Fe and unavoidable impurities;
Microtexture is by other the organizational composition beyond ferritic and this ferritic;
Average carbon density in these other the tissue, the carbon concentration whole with respect to steel plate is below 3.0 times;
The area occupation ratio of its hetero-organization beyond the ferritic is 5～20%;
Wherein, % is the meaning of quality %, down together.
2. the steel plate of putting down in writing according to claim 1; It is characterized in that; Also contain from following optional at least a kind: Zr:0.05% below and do not contain 0%, below the Ca:0.005% and do not contain 0%, below the Mg:0.005% and do not contain 0%, and REM:0.01% following and do not contain 0%.
3. according to the steel plate of claim 1 record, it is characterized in that, also contain: B:0.005% below and do not contain 0%, reach below the Ni:0.5% and do not contain 0% from following optional at least a kind.
4. the steel plate of putting down in writing according to claim 1; It is characterized in that, also contain from following optional at least a kind: Cu:0.5% below and do not contain 0%, below the Cr:0.5% and do not contain 0%, below the Mo:0.5% and do not contain 0%, below the V:0.1% and do not contain 0%, reach below the Nb:0.05% and do not contain 0%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2005101357835A CN1995432B (en) | 2005-12-28 | 2005-12-28 | Welding joint steel plated with excellent low-temperature flexibility |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2005101357835A CN1995432B (en) | 2005-12-28 | 2005-12-28 | Welding joint steel plated with excellent low-temperature flexibility |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1995432A CN1995432A (en) | 2007-07-11 |
| CN1995432B true CN1995432B (en) | 2012-01-18 |
Family
ID=38250633
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2005101357835A Active CN1995432B (en) | 2005-12-28 | 2005-12-28 | Welding joint steel plated with excellent low-temperature flexibility |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN1995432B (en) |
-
2005
- 2005-12-28 CN CN2005101357835A patent/CN1995432B/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| CN1995432A (en) | 2007-07-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US11453933B2 (en) | High-strength steel material having enhanced resistance to crack initiation and propagation at low temperature and method for manufacturing the same | |
| CN101400815B (en) | Steel sheet for submerged arc welding | |
| US20220002836A1 (en) | Hot-rolled steel strip & manufacturing method | |
| JP2017155300A (en) | Thick steel sheet for low temperature and manufacturing method therefor | |
| JP5903880B2 (en) | High-strength steel sheet for line pipes with excellent sour resistance and weld heat-affected zone toughness and method for producing the same | |
| JP6492862B2 (en) | Low temperature thick steel plate and method for producing the same | |
| JP2008255459A (en) | Thick steel plate having excellent haz toughness, base metal toughness, elongation and strength-elongation balance | |
| JP2019214752A (en) | Low-yield-ratio thick steel plate | |
| JP2011202214A (en) | Thick high tensile strength steel plate having excellent low temperature toughness in multilayer weld zone and method for producing the same | |
| KR20180074228A (en) | High strength steel having excellent fracture initiation resistance and fracture arrestability in low temperature, and method for manufacturing the same | |
| JP4891836B2 (en) | Steel plate with excellent toughness of weld heat affected zone in high heat input welding | |
| CN100513611C (en) | High-strength steel plate and process for production thereof, and high-strength steel pipe | |
| JP2005256037A (en) | Method for producing high strength-high toughness-thick steel plate | |
| JPH11229075A (en) | High strength steel excellent in delayed breakdown resistance, and its production | |
| JP4412098B2 (en) | Low yield ratio high strength steel sheet with excellent weld heat affected zone toughness and method for producing the same | |
| JP3893921B2 (en) | Low temperature Ni-containing steel and method for producing the same | |
| JP4637516B2 (en) | Steel sheet with excellent low temperature toughness of welded joints | |
| JP2012188749A (en) | Thick steel plate with high toughness in multi-pass welded part and multi-pass welded joint | |
| CN108603267B (en) | Steel material for high heat input welding | |
| CN1995432B (en) | Welding joint steel plated with excellent low-temperature flexibility | |
| JP2001335884A (en) | High strength thick steel plate excellent in ctod(crack tip opening displacement) characteristic, and its manufacturing method | |
| JP4507730B2 (en) | Low yield ratio high strength high toughness steel sheet and method for producing the same | |
| JP4284258B2 (en) | Steel sheet with low yield ratio and excellent toughness and welded joint toughness and its manufacturing method | |
| JP4742617B2 (en) | Manufacturing method of high-strength steel sheet with excellent weld heat-affected zone toughness | |
| JP4089455B2 (en) | High strength steel with excellent HIC resistance |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant |