CN101724780B - Thick steel plate - Google Patents
Thick steel plate Download PDFInfo
- Publication number
- CN101724780B CN101724780B CN2009102053093A CN200910205309A CN101724780B CN 101724780 B CN101724780 B CN 101724780B CN 2009102053093 A CN2009102053093 A CN 2009102053093A CN 200910205309 A CN200910205309 A CN 200910205309A CN 101724780 B CN101724780 B CN 101724780B
- Authority
- CN
- China
- Prior art keywords
- quality
- haz
- toughness
- contain
- nitride
- 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.)
- Expired - Fee Related
Links
Images
Classifications
-
- 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
- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
-
- 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
- C22C38/002—Ferrous alloys, e.g. steel alloys containing In, Mg, or other elements not provided for in one single group C22C38/001 - C22C38/60
-
- 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
- C22C38/005—Ferrous alloys, e.g. steel alloys containing rare earths, i.e. Sc, Y, Lanthanides
-
- 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
- C22C38/06—Ferrous alloys, e.g. steel alloys containing aluminium
-
- 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
- C22C38/12—Ferrous alloys, e.g. steel alloys containing tungsten, tantalum, molybdenum, vanadium, or niobium
-
- 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
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
The invention provides a steel plate with excellent HAZ toughness even in high heat input welding. The thick steel plate of the invention comprises predetermined chemical compositions; and, has Ti nitride content above 5.0X106/mm2 when the diameter of equivalent circle is smaller than 0.05 mum; has Ti nitride content above 1.0X105/mm2 when the diameter of equivalent circle is between 0.05 and 1.0 mum; and has the Ti nitride content below 5/mm2 when the diameter of equivalent circle is larger than 1.0 mum.
Description
Technical field
The present invention relates to be applicable to the Plate Steel of the welded structure of bridge, high-rise and boats and ships etc.; The Plate Steel that particularly relates to the tenacity excellent of the heat affected zone (following only be called " HAZ ") after the large-line energy welding also relates to mother metal (steel plate) and the Plate Steel of HAZ tenacity excellent after the large-line energy welding in addition.
Background technology
In recent years, along with the maximization of above-mentioned various welded structures, the welding of the Plate Steel that thickness of slab 50mm is above is inevitable.Therefore, in all areas, from this viewpoint of improving of welding procedure efficient, the situation of existence is to point to the above large-line energy welding of 50kJ/mm.
Yet if carry out large-line energy welding, HAZ is heated to Xu Leng after the pyritous austenite region, thus near HAZ portion (particularly the fusion portion of HAZ portion) organize thickization, the such problem of the easy deterioration of toughness of this part is arranged.The toughness (below be called " HAZ toughness ") of guaranteeing this HAZ portion well becomes problem all the year round.
The technology of the HAZ flexible deterioration when being used to prevent the large-line energy welding proposes to have various up to now.As this technological typical example; For example shown in the patent documentation 1～6, propose to have a kind of steel, it is to disperse to separate out fine TiN in the steel through making; Be suppressed at thickization of the austenite crystal that produces at HAZ that carries out large-line energy when welding, thereby suppress HAZ flexible deterioration.Yet in these technology; If welding base metal reaches the high temperature more than 1400 ℃, then among the HAZ, particularly at position (fusion portion) near welding base metal; Disappear because the thermal conductance that receives during welding causes above-mentioned TiN solid solution, have and fully to suppress the such problem of HAZ flexible deterioration.
In addition, in patent documentation 7, also propose a kind of technology, it is in order to suppress the generation that particle diameter surpasses this thick TiN of 0.1 μ m, has realized that particle diameter is suitableization of distribution of the fine TiN of 0.01～0.1 μ m, realizes that thus the HAZ flexible improves.Yet, only realize suitableization of the distribution of fine TiN, can not guarantee sufficient HAZ toughness.
So present inventors take the lead in patent documentation 8, even propose a kind of steel that also can not make the toughness deterioration of HAZ when when welding, receiving the pyritous heat affecting.In this technology, through heavy addition N in steel, and suitably control the interpolation balance of Ti and B, make after the welding solid solution not yet thus and the amount of the TiN that exists increases, thereby improve HAZ toughness.
In addition, present inventors also propose a kind of technology, make the TiN that is present in the welding steel contain Nb among the inclusion energetically, and control Ti/Nb ratio, and making particle diameter is the every 1mm of number of the inclusion of 0.01～0.25 μ m
2Be 1.0 * 10
4More than individual, guarantee the HAZ toughness (for example patent documentation 9) in the broad heat input scope thus.
Yet according to these technology, the above-mentioned TiN solid solution that the heat that receives in the time of still can not avoiding owing to welding causes disappears, and still has HAZ toughness that the problem of some deteriorations is arranged.Thus; As the method that remedies the disappearance that contains the Ti nitride, propose to have with oxide compound to generate the technology (for example, patent documentation 10) that point is applied flexibly as containing the Ti nitride; With technology of applying flexibly as the pinning particle with the oxide compound of high temperatures (for example, patent documentation 11,12) etc.
In addition, in patent documentation 13, propose to have a kind of technology, it is through promoting inclusion with oxide compound etc. as the ferritic generation of the intracrystalline of starting point, thereby makes HAZ organize miniaturization, to guarantee HAZ toughness.But the inclusion of these oxide compounds etc. is applied flexibly technology, and making easily has dysgenic thick inclusion to generate to toughness, and in addition, the inclusion of general oxide compound etc. can be that The amount of inclusions is lacked than TiN, therefore is difficult to obtain stable HAZ toughness.
Yet oxide compound lacks than containing Ti nitride quantity, can not get sufficient HAZ flexible problem.In addition, in applying flexibly the technology of oxide compound, cause easily, the good problem of toughness that can not stably make mother metal and HAZ is arranged because of thick oxide compound generates the mother metal that brings and the tough sexual deviation of HAZ.And even fine tissue is formed, if there be thick Ti nitride and the island martensite body (MA) of containing, then its starting point as brittle rupture works, and also can cause the flexible deviation.
[patent documentation 1] special public clear 55-26164 communique
[patent documentation 2] spy opens the 2003-166017 communique
[patent documentation 3] spy opens the 2003-213366 communique
[patent documentation 4] spy opens the 2001-20031 communique
[patent documentation 5] spy opens the 2008-121074 communique
[patent documentation 6] spy opens the 2003-160834 communique
[patent documentation 7] spy opens the 2001-98340 communique
[patent documentation 8] spy opens the 2005-200716 communique
[patent documentation 9] spy opens the 2004-218010 communique
[patent documentation 10] spy opens the 2003-321728 communique
[patent documentation 11] spy opens the 2007-100213 communique
[patent documentation 12] spy opens the 2005-336602 communique
[patent documentation 13] spy opens the 2008-223081 communique
Summary of the invention
The present invention is in view of such situation and doing, and its purpose is, a kind of the steel plate that HAZ toughness is also good provides a kind of HAZ tenacity excellent in addition when carrying out the large-line energy welding even provide, and the also excellent Plate Steel of the toughness of mother metal self.
Can solve the Plate Steel of the present invention of above-mentioned problem; It has following some main idea: contain (not containing 0 quality %), Al:0.005～0.05 quality %, Ti:0.010～0.080 quality %, Nb:0.002～0.10 quality %, Ca:0.0005～0.010 quality % and N:0.002～0.020 quality % below (not containing 0 quality %), the S:0.015 quality % below (containing 0 quality %), Mn:1.0～2.0 quality %, the P:0.03 quality % below C:0.03～0.15 quality %, the Si:0.25 quality % respectively; Surplus is iron and unavoidable impurities, contains the every 1mm of Ti nitride in what diameter of equivalent circle was lower than 0.05 μ m
2Have 5.0 * 10
6More than individual, contain the every 1mm of Ti nitride in diameter of equivalent circle 0.05～1.0 μ m
2Have 1.0 * 10
5Contain the every 1mm of Ti nitride more than individual and in what diameter of equivalent circle surpassed 1.0 μ m
2Exist below 5.Such Plate Steel HAZ toughness is good.
Also have; Above-mentioned what is called " diameter of equivalent circle "; Be the size that is conceived to contain the Ti nitride, try to achieve the circular diameter of the such supposition that equates with its area, it is the diameter of the nitride on the viewpoint face of transmission electron microscope (TEM) and scanning electron microscope (SEM), confirmed.Its aim of Ti nitride that contains as object among the present invention is, comprises TiN certainly, also comprise a part with other nitride forming elements (for example Nb, Zr, V etc.) displacements Ti (with atomic ratio measuring be below 50% about) nitride.
In Plate Steel of the present invention, (t: the area ratio of the island martensite body of position thickness of slab) is below 5%, and the toughness of then HAZ tenacity excellent, and mother metal self also improves, and is therefore preferred if further make apart from the surface dark t/4.
In addition; Also containing (not containing 0 quality %) below (not containing 0 quality %), the Cr:1.5 quality % below (not containing 0 quality %), the Cu:1.5 quality % and the element more than a kind among (not containing 0 quality %) below the Mo:1.5 quality % below the Ni:1.5 quality %, also is the optimal way of Plate Steel of the present invention.
Perhaps; Contain (not containing 0 quality %) below (not containing 0 quality %), the Cr:1.5 quality % below (not containing 0 quality %), the Cu:1.5 quality % and the element more than a kind among (not containing 0 quality %) below the Mo:1.5 quality % below the Ni:1.5 quality %; And the A value with following formula (1) expression is 125≤A≤200, and adjusts, make it and the G value represented by following formula (2) between; Relation with A/G>=4350, this also is another optimal way of Plate Steel of the present invention.
A＝53+104[C]+76[Cu]+109[Cr]+37[Ni]+2422[Nb]+31[Mo]…(1)
G＝[Nb]+5[B]…(2)
[formula (1), in (2), [] represented the content (quality %) of each element.]
In Plate Steel of the present invention, contain like inferior element also useful as required again: (a) (not containing 0 quality %) below the V:0.1 quality %; (b) (not containing 0 quality %) below the B:0.005 quality %; (c) below (not containing 0 quality %) below the Zr:0.02 quality %, the REM:0.02 quality % among (not containing 0 quality %) more than a kind, through containing these elements, corresponding its kind, the characteristic of Plate Steel is further improved.
According to the present invention, the chemical ingredients composition of steel plate is included in the suitable scope, and suitably made it to disperse according to the size that contains the Ti nitride, therefore can realize the improved Plate Steel of toughness of welding heat affected zone (HAZ).
In addition, also pass through further to suppress the area ratio of the island martensite body in the tissue, thereby can realize the improved Plate Steel of toughness of mother metal and welding heat affected zone (HAZ).
In addition, be equivalent to the A value of the motivating force of bainitic transformation through further control, and suitably control can realize the Plate Steel that HAZ toughness is further enhanced thus to the relation (A/G) of austenite grain boundary influential G value of ability and said A value.
Description of drawings
Fig. 1 is the graphic representation of the relation of expression A value and A/G value and HAZ bainite structure.Visible by Fig. 1, along with A value and A/G value rise, the bainite structure size has the tendency that diminishes.
Embodiment
Present inventors, still residual the containing of fusion obtained success (said patent documentation 9) aspect Ti nitride (following represent with the TiN) increase under making the high temperature in when welding, is basis with this technology, studies repeatedly in order further to improve HAZ toughness.
In the technology that proposes up to now; Fine TiN is disperseed in a large number; This is considered to improving on the HAZ toughness is effective means; But make HAZ toughness good aspect, find it would be better to the number of control TiN (promptly containing the Ti nitride), make it to increase and get final product with the number that diameter of equivalent circle is counted the size about 0.05～1.0 μ m.
Distinguish also that in addition finer TiN (count be lower than 0.05 μ m with diameter of equivalent circle) compared with HAZ toughness, is to make well needs more of base metal tenacity on the contrary.The TiN blending dispersion of (the counting 0.05～1.0 μ m) if of this fine TiN and above-mentioned size with diameter of equivalent circle; And control the generation of thick (surpassing 1.0 μ m) TiN in diameter of equivalent circle; Then find to realize the Plate Steel of HAZ tenacity excellent, thereby accomplish the present invention.
In Plate Steel of the present invention, through after the control stated, the TiN of various size is suitably disperseed, and stipulates the reasons are as follows of these important documents.
[be lower than the every 1mm of TiN of 0.05 μ m in diameter of equivalent circle
2Be 5.0 * 10
6More than individual]
Be lower than the TiN of 0.05 μ m in diameter of equivalent circle, thickization of the austenite crystal when suppressing rolling (γ grain) is being used to guarantee needs on the toughness of HAZ and mother metal.If the number of the TiN of this size is than every 1mm
2Be 5.0 * 10
6Individual (5.0 * 10
6Individual/mm
2) few, then can not get the stable base metal tenacity of body.
[in the every 1mm of TiN of diameter of equivalent circle 0.05～1.0 μ m
2Be 1.0 * 10
5More than individual]
The TiN that counts 0.05～1.0 μ m with diameter of equivalent circle suppresses thickization of γ grain of HAZ, is being used to guarantee needs on the good HAZ toughness.If the number of the TiN of this size is than every 1mm
2Be 1.0 * 10
5Individual (1.0 * 10
5Individual/mm
2) few, then can not get the stable HAZ toughness of body.Also have, the size of TiN was than 0.05 μ m hour, though help base metal tenacity, fusion easily is little to the help of the tough property improvement of HAZ in the large-line energy welding.In addition, if this size is bigger than 1.0 μ m, then can give the toughness deleterious impact of mother metal and HAZ.
[the every 1mm of TiN that surpasses 1.0 μ m in diameter of equivalent circle
2Be below 5]
The thick TiN that surpasses 1.0 μ m in diameter of equivalent circle can be to the toughness deleterious impact of mother metal and HAZ, therefore preferred the least possible method.From this viewpoint, in the present invention, the TiN that surpasses 1.0 μ m in diameter of equivalent circle is defined as every 1mm
2At below 5 (5/mm
2Below).
Also find in addition,, then can realize except HAZ toughness, the Plate Steel that the toughness of mother metal is also excellent if further suppress the generation of the island martensite body (MA) of prescribed position.
In Plate Steel of the present invention, make the area ratio of island martensite body (MA) be in the reasons are as follows in the scope of regulation.
[the dark t/4 apart from the surface (t: the area ratio of the island martensite body of position thickness of slab) is below 5%]
Plate Steel of the present invention; It is organized basically and is made up of ferritic and bainite; But island martensite body (MA) works as the brittle rupture starting point, and base metal tenacity is caused detrimentally affect, so the area ratio of island martensite body need be suppressed at below 5%; If its area ratio surpasses 5%, then can not get stable base metal tenacity.Also have, why make the prescribed position of the area ratio of island martensite body be " dark t/4 (t: position thickness of slab) " apart from the surface, selection be the representational position of the characteristic of expression steel plate.
In order to realize dispersion state and the microstructure (area ratio of island martensite body) of above-mentioned such TiN; In molten steel, make the interpolation of Al and Ca be Al → Ca in proper order; Hold-time to casting is controlled at more than 10 minutes, is lower than 90 minutes; And to make the cooling time under 1500～1400 ℃ of when casting be in 600 seconds; And after heating condition before rolling is controlled at 1050～1200 ℃ * 2～5 hours, implementing roughing more than 900 ℃, and to make speed of cooling be that to stop temperature be that 300～500 ℃ of coolings after being rolled get final product for 2～15 ℃/second, cooling.The regulation of each important document the reasons are as follows.
[in molten steel, making the interpolation of Al and Ca be Al → Ca in proper order]
If make the interpolation of these elements be Ca → Al in proper order, then in molten steel, generate Ca oxide compound and Al oxide compound.These oxide compounds become the generation starting point of thick TiN easily, owing to increase in the thick TiN of diameter of equivalent circle above 1.0 μ m, cause mother metal and HAZ toughness deterioration easily.With respect to this, if add, then can generate the Ca-Al composite oxides of the generation starting point that is difficult to become TiN with the order of Al → Ca, the generation of thick TiN is inhibited.
[the hold-time T1 to casting is more than 10 minutes, is lower than 90 minutes]
Hold-time T1 to casting is the important document that the generating state to the Ca-Al composite oxides exerts an influence; When this hold-time, T1 was lower than 10 minutes; The Ca-Al composite oxides can't fully generate, and cause mother metal that the generation increase because of thick TiN brings and the toughness deterioration of HAZ.On the other hand, if this hold-time T1 surpasses 90 minutes, then thickization of composite oxides brings the toughness detrimentally affect of mother metal and HAZ.
[T2 cooling time under 1500～1400 ℃ during casting is in 600 seconds]
If [T2 cooling time under 1500～1400 ℃ during casting surpasses 600 seconds, and then the growing amount of thick TiN increases, and the growing amount of counting the TiN of 0.05～1.0 μ m with diameter of equivalent circle reduces, and can not guarantee sufficient base metal tenacity and HAZ toughness.
[heating condition before rolling: 1050～1200 ℃ * 2～5 hours]
This rolling heating condition can impact the form of TiN, if Heating temperature Th at this moment is lower than 1050 ℃, perhaps heat-up time, T3 was than 2 hours weak points, then can't fully obtain to count with diameter of equivalent circle the TiN of 0.05～1.0 μ m.If Heating temperature Th is higher than 1200 ℃, heat-up time, T3 was than 5 little durations, and then the Ostwald of TiN growth promotes, can't fully obtain to count the TiN that is lower than 0.05 μ m with diameter of equivalent circle.
[implementing roughing more than 900 ℃]
The temperature of roughing (roughing end temp Tf) can't fully obtain to count the TiN that is lower than 0.05 μ m with diameter of equivalent circle, the base metal tenacity deterioration when being lower than 900 ℃.
[the speed of cooling Rc:2 after rolling～15 ℃/second, it is 300～500 ℃ that cooling stops temperature T s]
If the speed of cooling Rc after rolling is slower than 2 ℃/second, then thick ferritic generates, the base metal tenacity deterioration, if than 15 ℃/second fast, then the growing amount of island martensite body (MA) increases, the base metal tenacity deterioration.In addition, when cooling stopped temperature T s and is lower than 300 ℃, the growing amount of island martensite body (MA) increased, the base metal tenacity deterioration.In addition, surpass 500 ℃ if cooling stops temperature T s, then soft tissue increases, and intensity reduces.Also have, when cooling stops temperature T s and is lower than 300 ℃,, also can access stable toughness through carrying out the temper about 500 ℃ thereafter.
Next, the chemical ingredients composition for Plate Steel of the present invention (mother metal) describes.As above-mentioned, even Plate Steel of the present invention satisfies the distribution of TiN and the microstructure of prescribed position, if but the content of each chemical ingredients (element) be not in the proper range, then still can not reach excellent HAZ toughness and base metal tenacity.Therefore in Plate Steel of the present invention, except the distribution situation of TiN (containing the TiN nitride) was good, the amount of each chemical ingredients also need be in the proper range of the following stated.Particularly making Si content is below the 0.02 quality %, and this guarantees on more good base metal tenacity and the HAZ toughness exceedingly useful reducing the thick generation that contains the Ti nitride.
[C:0.03～0.15 quality %]
C is used to guarantee the intensity of steel plate and the element that can not lack.When C content is lower than 0.03 quality %, can not guarantee the intensity of steel plate.Be preferably more than the 0.04 quality %.But if C content is superfluous, then the island martensite body (MA) of hard is a large amount of generates, and causes the toughness deterioration of HAZ toughness and mother metal.Therefore C content need be suppressed at below the 0.15 quality % and (be preferably below the 0.12 quality %, more preferably below the 0.10 quality %, further be preferably below the 0.09 quality %).
[below the Si:0.25 quality % (containing 0 quality %)]
Si is useful element on the intensity of guaranteeing steel plate through solution strengthening, but through reducing as much as possible, can suppress to contain thickization of Ti nitride, makes the toughness of mother metal and HAZ good.If Si content is superfluous, then the island martensite body (MA) of hard is a large amount of generates, and causes the toughness deterioration of mother metal.Therefore Si content need be suppressed at below the 0.25 quality % at least.Particularly in order to reduce the generation of the thick Ti of containing nitride, guarantee more good base metal tenacity and HAZ toughness, preferred Si content is below the 0.15 quality %, more preferably below 0.05 quality %, most preferably below 0.02 quality %.
[Mn:1.0～2.0 quality %]
Mn is guaranteeing on the intensity of steel plate it is useful element, in order to bring into play this effect effectively, need make it to contain more than the 1.0 quality %.Be preferably more than the 1.2 quality %, more preferably more than the 1.4 quality %.But, contain if surpass 2.0 quality % superfluously, then the intensity of HAZ excessively rises, the toughness deterioration, so Mn content is below the 2.0 quality %, is preferably below the 1.8 quality %, more preferably below the 1.7 quality %.
[below the P:0.03 quality % (not containing 0 quality %)]
P as impurity element causes intercrystalline cracking easily, gives the toughness deleterious impact, and therefore preferred its content is the least possible.From guaranteeing this viewpoint of flexible, P content need be suppressed at below the 0.03 quality %, preferably below 0.02 quality %.But making P in the steel reach 0 quality % in the industry has any problem.
[below the S:0.015 quality % (not containing 0 quality %)]
S is the impurity that makes the toughness deterioration of mother metal, and preferably its content is few as much as possible.From guaranteeing this viewpoint of flexible, S content need be suppressed at below the 0.015 quality %, preferably below 0.010 quality %.But making S in the steel reach 0 quality % in the industry has any problem.
[Al:0.005～0.05 quality %]
As aforementioned, it is the element useful to the crystallization that suppresses thick TiN through before Ca, adding.In order to bring into play this effect, its content need be for more than the 0.005 quality %, but superfluous as if its content, then thick TiN generates, and therefore the toughness deterioration of mother metal and HAZ need be suppressed at below the 0.05 quality %.The preferred lower limit of Al content is 0.010 quality %, and preferred upper limit is 0.04 quality %.
[Ti:0.010～0.080 quality %]
Ti and N react and the nitride of formation all size, are the elements that helps the toughness raising of mother metal and HAZ.In order to bring into play this effect effectively, Ti is contained more than the 0.010 quality %, be preferably more than the 0.012 quality %.But if contain superfluously, then thick TiN generates in a large number, makes the toughness deterioration of mother metal and HAZ, therefore should be suppressed at below the 0.080 quality %.Be preferably below the 0.060 quality %.
[Nb:0.002～0.10 quality %]
Nb separates out as carbonitride, suppresses thickization of γ grain, is at the element that base metal tenacity is effectively played a role on good.This effect is that 0.002 quality % is brought into play when above effectively at Nb content, but in order more effectively to bring into play this effect, preferably makes it to contain more than the 0.005 quality %.But, if Nb content is superfluous, then cause separating out of thick carbonitride, therefore the base metal tenacity deterioration need (be preferably below the 0.08 quality %) below the 0.10 quality %.
[Ca:0.0005～0.010 quality %]
Ca is to effective elements in the crystallization that suppresses thick TiN through after Al, adding.In order to bring into play this effect, Ca is contained more than the 0.0005 quality %, be preferably more than the 0.0008 quality %.But if Ca content is superfluous, then thick oxide compound generates, and the toughness deterioration of mother metal and HAZ therefore need be below 0.010 quality %.Be preferably below the 0.008 quality %.
[N:0.002～0.020 quality %]
N at high temperature forms the residual nitride (containing the Ti nitride) of fusion, is useful element on the toughness of guaranteeing mother metal and HAZ.Through making N content is (to be preferably more than the 0.003 quality %) more than the 0.002 quality %, and that can guarantee to stipulate contains the Ti nitride.But if N content is superfluous, then solid solution N amount increases, because strain aging causes the toughness deterioration of mother metal and HAZ.Therefore, N need be suppressed at below the 0.020 quality %, is preferably below the 0.018 quality %.
The present invention regulation contain element such as above-mentioned, surplus is iron and unavoidable impurities, as this unavoidable impurities, element (for example Sn, As, the Pb etc.) that can allow to infiltrate because of the situation of raw material, goods and materials, producing apparatus etc. sneak into.In addition, it is also effective to contain following element more energetically, and according to the kind of the composition that is contained, the characteristic of steel plate is further improved.
[among (not containing 0 quality %) below (not containing 0 quality %), the Cr:1.5 quality % below (not containing 0 quality %) below the Ni:1.5 quality %, the Cu:1.5 quality % and the Mo:1.5 quality % following (not containing 0 quality %) more than a kind]
Ni, Cu, Cr and Mo all are the high strength effective elements to steel plate, and its effect increases and increases along with its content, in order to bring into play this effect effectively, all preferably makes it to contain more than the 0.05 quality %.More preferably more than the 0.10 quality %.But if the content of these elements is superfluous, then cause the excessive rising of intensity, therefore the toughness deterioration of mother metal and HAZ all preferably is suppressed at below the 1.5 quality %.More preferably below the 1.2 quality %.
[below the V:0.1% (not containing 0%)]
V separates out as carbonitride, suppresses thickization of γ grain, is at the element that base metal tenacity is effectively played a role aspect good.This effect increases and increases along with its content, in order to bring into play this effect effectively, preferably makes it to contain (more preferably more than 0.005%) more than 0.002%.Yet, if V content is superfluous, cause separating out of thick carbonitride, therefore the base metal tenacity deterioration is (to be preferably below 0.08%) below 0.1%.
[below the B:0.005% (not containing 0%)]
The generation of the grain boundary ferrite that the B inhibition is thick is an effective elements on the toughness of mother metal and HAZ improves.This effect increases and increases along with its content, in order to bring into play this effect effectively, preferably makes it to contain (more preferably more than 0.0015%) more than 0.0010%.But if B content is superfluous, then cause the separating out of BN of austenite grain boundary, mother metal and HAZ toughness deterioration, so preferably below 0.0050%.More preferably below 0.0040%.
[(not containing 0%) and/or REM:0.02% below the Zr:0.02% following (not containing 0%)]
Zr and REM (rare earth element) make the oxide compound miniaturization, are the elements that helps the toughness raising of HAZ.This effect increases and increases along with its content, in order to bring into play this effect effectively, all preferably makes it to contain (more preferably more than 0.0005%) more than 0.0001%.But if surplus contains, then oxide compound becomes thick, makes the toughness deterioration of mother metal and HAZ, therefore all should be suppressed at below 0.02%.Preferably below 0.015%.Also have, in the present invention, so-called REM (rare earth element) meaning is to comprise lanthanon (15 elements from La to Ln) and Sc (scandium) and Y (yttrium).
; In Plate Steel of the present invention, contain any one of said Ni, Cu, Cr, Mo when above, except the control of above-mentioned TiN; The control of the bainitic transformation motivating force of bringing through the optimizing of utilizing the alloying element addition can further improve HAZ toughness.Present inventors are conceived to utilize this bainitic transformation motivating force to control the technology of the bainite structure miniaturization of the HAZ that brings, further research repeatedly.Its result can know that the factor beyond the bainitic transformation motivating force brings influence also can for the size of the bainite structure of HAZ, is that austenite grain boundary can exert an influence specifically.
Therefore, recommend in the present invention: (i) control is equivalent to the A value of bainitic transformation motivating force, and (ii) stipulates to influence the G value of austenite grain boundary ability, control A/G.Thus, the nucleus formation frequency of the bainite in the crystal boundary increases, the miniaturization that can reach the bainite structure of HAZ, and HAZ toughness further improves.
About (i)
At first, study with regard to the motivating force of bainitic transformation and the influence of various alloys.If consider the forming process of bainitic transformation, then think the temperature that its motivating force can begin to take place with the motivating force of bainitic transformation (below be called " T
0Temperature ") and the temperature of the actual generation of bainitic transformation (below be called " B
sPoint ") difference describe.
Therefore, with regard to each temperature (T
0Temperature, B
sPoint) influence of pairing alloying element is further studied.About T
0Temperature owing to can calculate through calculation of thermodynamics, is therefore used calculation of thermodynamics software (Thermo-calc can buy from the CRC synthetic study), studies with regard to the influence of each alloying element, carries out formulism for the influence of each element.On the other hand, about B
sPoint is because can not calculate, so adopt experimental value in theory.That is, for forming different a plurality of steel grades, the condition of the embodiment that states later on (be heated to 1400 ℃ and keep after 60 seconds, with the TR of 800～500 ℃ of coolings in 500 seconds) is carried out thermal cycling test, tries to achieve B at this moment
sPoint is through the influence formulism of regression analysis with each element.Two formula (T that obtain
0Temperature, B
sPoint) poor is according to (T
0Temperature-B
sPoint) formula can be tried to achieve the A value by following formula (1) expression.
A＝53+104[C]+76[Cu]+109[Cr]+37[Ni]+2422[Nb]+31[Mo]…(1)
In the present invention, making the represented A value of following formula (1) is 125≤A≤200.If the A value is lower than 125, then can not guarantee sufficient phase driving force, so thickization of bainite structure.On the other hand, if the A value surpasses 200, then martensitic transformation takes place, because the martensitic phase of hard causes HAZ toughness deterioration.The A value is preferably 135≤A≤180.
Next, can study with the influence of various alloying elements with regard to austenite grain boundary.In general, Nb and B are known as the element that reduces the austenite grain boundary ability.Therefore, prepare several steel grades that make Nb amount and B quantitative changeization with the A value of degree that have, respectively it is measured the bainite structure size of HAZ.Consequently, the B amount is 5 times that Nb measures for the influence of bainite structure size approximately, thus, as the index that can exert an influence to austenite grain boundary, adopts G=[Nb]+5 [B].If have the effect that reduces crystal boundary energy Nb and B to contain quantitative change many, then can know that by following formula (2) G value becomes greatly, the value of G means that greatly promptly the austenite grain boundary ability is little.Also have, B (boron) is an arbitrary element in the present invention, calculates the G value with [B]=0 when not containing B.
G＝[Nb]+5[B]…(2)
If austenite grain boundary can be low (be above-mentioned G value big), then austenite grain boundary is stable, and the crystal boundary bainite of eliminating this stable crystal boundary is difficult to generation.That is, even more than regulation, keep being equivalent to the A value of bainitic transformation motivating force, during austenite grain boundary ability low (the G value is big), bainitic transformation still is difficult to generate.Therefore in the present invention, control A/G makes it to be A/G >=4350.If A/G is lower than 4350, then the nucleus formation frequency of crystal boundary bainite reduces, and thick bainite structure forms.A/G is preferably more than 4400.In addition, the upper limit of G value is not special to be limited, and is approximately below 50000.
The present invention relates to Plate Steel, so-called Plate Steel is defined like JIS in this field, refers generally to thickness of slab more than 3.0mm.But Plate Steel of the present invention; Even for thickness of slab is that to carry out heat input be the large-line energy welding more than the 50kJ/mm to steel plate such more than the 50mm; Have and demonstrate good HAZ toughness; Therefore being applied on the steel plate of this thickness is preferred mode, but the thickness of steel plate of the present invention is not limited to more than the 50mm, and is not precluded within the application on the steel plate that thickness of slab is lower than this.
The Plate Steel of the present invention that so obtains; Can use as the material of the for example works of bridge, high-rise and boats and ships etc.; Much less little～middle heat input welding, even in the large-line energy welding, also can prevent the toughness deterioration of mother metal and welding heat affected zone.
[embodiment]
Below, illustrate in greater detail the present invention through embodiment, but following embodiment does not limit character of the present invention, also can suitably change enforcement in the scope of the aim of before and after can meeting, stating, these all are included in the technical scope of the present invention.
[embodiment 1]
Control below table 3, the condition shown in 4 (the interpolation order of Al, Ca, the hold-time T1 that extremely casts) on one side; The steel of the below table of melting on one side 1, the composition shown in 2; T2 cooling time of (1500～1400 ℃ TRs) during control casting on one side; Cooling on one side should molten steel, become slab (behind cross-sectional shape: the 150mm * 250mm), with below table 3, the rolling condition shown in 4 (Heating temperature Th before rolling, rolling before heat-up time T3, roughing end temp Tf) be rolled; Become the hot-rolled sheet of thickness of slab 80mm, be cooled to cooling in rolling back with speed of cooling Rc and stop temperature T s.In addition, as required, implement temper with 500 ℃.Also have, in table 1, REM is about 50% to be that the form of about 25% norium is added with containing Ce to contain la.In addition, element is not added in "-" expression in the table 1.In addition in table 3,4, the interpolation of Al, Ca order is " zero " when Al → Ca, when Ca → Al, is " * ".
For each test board of manufacturing like this, measure the toughness of area ratio (branch rate), Plate Steel (mother metal) and HAZ of the individual number density that contains the Ti nitride, the island martensite body (MA) of all size with following main points.These results are presented in the table 5,6.
[being lower than the mensuration of the individual number density that contains the Ti nitride of 0.05 μ m in diameter of equivalent circle]
From dark t/4 (t: test film under cut position thickness of slab) (extract test film and make its shaft core position) through the t/4 position apart from the surface of each steel plate; (replica) TEM test film is duplicated in cross section making by being parallel to rolling direction and thickness of slab direction; With transmission electron microscope (TEM), observe with the condition of observing 60000 times of multiplying powers, field of view 2 * 2 (μ m), observation 5 places, place.Through image analysis, measure the area that respectively contains the Ti nitride in this visual field then, calculate the diameter of equivalent circle of each nitride by this area.Also have, contain the Ti nitride and differentiate through EDX (energy dispersion type X ray detector).Then, the number that contains the Ti nitride that diameter of equivalent circle is lower than 0.05 μ m is converted into every 1mm
2Try to achieve.But, be to contain the Ti nitride below the 0.01 μ m about diameter of equivalent circle, the safety of EDX is also insufficient, therefore from analyze except.
[in the mensuration of the individual number density that contains the Ti nitride of diameter of equivalent circle 0.05～1.0 μ m]
With transmission electron microscope (TEM),, observe the above-mentioned TEM test film that duplicates to observe the condition at 15000 times of multiplying powers, field of view 8 * 8 (μ m), observation 5 places, place.Through image analysis, measure the area that respectively contains the Ti nitride in this visual field then, calculate the diameter of equivalent circle of each nitride by this area.Also have, contain the Ti nitride and differentiate through EDX (energy dispersion type X ray detector).Then, the number that contains the Ti nitride with diameter of equivalent circle 0.05～1.0 μ m is converted into every 1mm
2Try to achieve.
[mensuration that surpasses the individual number density that contains the Ti nitride of 1.0 μ m in diameter of equivalent circle]
From dark t/4 (t: test film under cut position thickness of slab) apart from the surface of each steel plate; Use the field emission type sem " SUPRA35 (trade(brand)name) " of Carl Zeiss corporate system; Observation is parallel to the cross section of rolling direction and thickness of slab direction, to observe 1000 times of multiplying powers, field of view 0.06 μ m
2, the condition of observing 20 places, place observes.Surpass the inclusion particle of 1.0 μ m for diameter of equivalent circle, by EDX differentiate contain N contain the Ti nitride.Then, the number that contains the Ti nitride that diameter of equivalent circle is surpassed 1.0 μ m is converted into every 1mm
2Try to achieve.
[mensuration of the area ratio of island martensite body (MA)]
From dark t/4 (t: test film under cut position thickness of slab) apart from the surface of each steel plate; With behind the corrosion of レ ペ ラ reagent and the rolling direction cross section parallel with the thickness of slab direction; Take 3 visuals field with opticmicroscope with 400 times, through the area ratio (branch rate) of image analysis calculation island martensite body (MA).
[toughness of mother metal]
From apart from the dark t/4 in surface of each steel plate (t: position thickness of slab), extract pendulum impact test sheet (No. 4 test films of JIS Z 2201) in rolling direction, under-60 ℃, carry out pendulum impact test according to JIS Z 2242, measure that absorb can (vE
-60).At this moment measure for 3 test films and absorb ability (vE
-60), calculate its Schwellenwert.
[evaluation of HAZ flexible]
From apart from the dark t/4 in surface of each steel plate (t: position thickness of slab), extract pendulum impact test sheet (No. 4 test films of JIS Z 2201) in rolling direction, simulate the thermal cycling test of large-line energy welding, estimate HAZ toughness.At this moment thermal cycling test be with above-mentioned test film be heated to 1400 ℃ and kept for 60 seconds after, spend 800～500 ℃ TR of cooling in 500 seconds, apply thus and be equivalent to the thermal cycling that weld heat input is 55kJ.According to JIS Z 2242, under-40 ℃, carry out pendulum impact test, measuring absorption can (vE
-40).At this moment measure for 3 test films and absorb ability (vE
-40), calculate its Schwellenwert.Then, vE
-40Schwellenwert surpass 100J be evaluated as the HAZ tenacity excellent.
Can investigate (also have, following No. representes the steel No. of table 1～6) as follows by these results.The example of important document two aspects of area ratio of important document and island martensite body (MA) of the individual number density that contains the Ti nitride of the present invention regulation is satisfied in No.1～25th; It is suitable that the dispersion of Ti nitride is formed, contained to chemical ingredients; And the generation of MA also is inhibited, and can know that the toughness that can access mother metal is good, given play to Schwellenwert and surpassed the excellent performance of the such base metal tenacity of 100J; And the toughness of welding heat affected zone is also good, vE
-40Schwellenwert surpass the such steel plate of 100J.
With respect to this, the C content in its steel plate of No.36 is the higher limit of the scope of the present invention's regulation, and the toughness of welding heat affected zone is with vE
-40Schwellenwert count below the 100J.
On the other hand, No.26～35,37～43rd, the example of a certain important document of disengaging the present invention regulation, the poor toughness of welding heat affected zone.Details as Follows.
The interpolation order of its Al of No.26 and Ca is improper, and the thick Ti nitride that contains increases the toughness deterioration of mother metal and HAZ.No.27 is short to the hold-time of casting, and the thick Ti nitride that contains increases the toughness deterioration of mother metal and HAZ.No.28 is long to the hold-time of casting in addition, and to stop temperature low in cooling in addition, the thick increase of Ti nitride, the toughness deterioration of mother metal and HAZ of containing.
Surpass 600 seconds the cooling time in No.29 when casting, and the speed of cooling after rolling in addition is fast,, the thick Ti nitride that contains increases, and reduces the toughness deterioration of mother metal and HAZ in the number that contains the Ti nitride of diameter of equivalent circle 0.05～1.0 μ m.No.30 is short to the hold-time of casting, and the thick Ti nitride that contains increases the toughness deterioration of mother metal and HAZ.
Mn content in its steel plate of No.31 surpasses the scope of the present invention's regulation, and rolling in addition preceding Heating temperature is high, and the number that contains the Ti nitride that is lower than 0.05 μ m in diameter of equivalent circle is not enough, can not get the toughness of good mother metal and HAZ.Si content in its steel plate of No.32 surpasses the scope of the present invention's regulation, and the growing amount of the MA of hard increases, and causes the toughness deterioration of mother metal and HAZ thus.
The content of P in its steel plate of No.33 surpasses the scope of the present invention's regulation, and rolling in addition preceding heat-up time is short, the toughness deterioration of mother metal and HAZ.The scope of the discontented unabridged version invention of the Al content in its steel plate of No.34 regulation, rolling in addition preceding heat-up time is elongated, and the thick generation that contains the Ti nitride can not get suppressing the toughness deterioration of mother metal and HAZ.
No.35 is short rolling preceding heat-up time, HAZ toughness deterioration.Al in the No.37 steel plate and Si content surpass the scope of the present invention's regulation, the toughness deterioration of mother metal and HAZ.
Ti content in the No.38 steel plate surpasses the scope of the present invention's regulation, and the thick Ti nitride that contains increases the toughness deterioration of mother metal and HAZ.
The scope of the discontented unabridged version invention of the Ca content in No.39 steel plate regulation, the thick Ti nitride that contains increases the toughness deterioration of mother metal and HAZ.
Ca content in the No.40 steel plate surpasses the scope of the present invention's regulation, can envision the generation of thick oxide compound, the toughness deterioration of mother metal and HAZ.
N content in the No.41 steel plate surpasses the scope of the present invention's regulation, even it is good to contain the form of Ti nitride, the toughness of mother metal and HAZ is deterioration still.
No.42,43 Ni content and Cu content as preferred composition surpass the scope that the present invention stipulates respectively, even it is good to contain the form of Ti nitride, the toughness of mother metal and HAZ is deterioration still.
[embodiment 2]
With the condition shown in table 10～12, the steel that melting, the chemical ingredients of casting shown in table 7～9 are formed becomes slab and (behind cross-sectional shape: the 150mm * 250mm), carries out hot rolling, obtain the hot-rolled sheet of thickness of slab 80mm.Also have, in table 7～9, REM is about 50% to be that the form of about 25% norium is added with containing Ce to contain la.In addition, in table 10～12, the interpolation of so-called Al, Ca is " zero " in proper order, and the meaning is to add by the order of Al → Ca.
From like cutting test sheet on the above-mentioned hot-rolled sheet that obtains,, measure HAZ toughness in addition in the following manner by the individual number density that contains the Ti nitride that following main points and embodiment 1 likewise measure all size.
The HAZ flexible is measured
From apart from dark t/4 position, the surface of each hot-rolled sheet, extract pendulum impact test sheet (the standard test sheets of JISZ 2242 defineds) in rolling direction, simulate the thermal cycling test of large-line energy welding, estimate HAZ toughness.At this moment thermal cycling test be with above-mentioned test film be heated to 1400 ℃ and kept for 60 seconds after, spend 800～500 ℃ TR of cooling in 500 seconds, be equivalent to the welding that weld heat input is 55kJ., according to JIS Z 2242, under-40 ℃ temperature carry out pendulum impact test, measure vE thereafter
-40Test is carried out on 3 test films, this vE
-40MV surpass 190J to be evaluated as HAZ toughness very excellent.Also have, in a～f of table 12, also show the vE of 3 test films
-40Minimum value.
The result is presented in table 10～12.
Table 10, the No.1 shown in 11～32 become to be grouped into, the value of A value, A/G suitably controlled, and creating conditions has in addition also obtained suitable control, so TiN satisfies important document of the present invention, reach vE
- 40MV surpass the so extremely good HAZ toughness of 190J.
On the other hand, its C of No.33 measures within the scope of the invention, since high slightly, so HAZ toughness is with vE
-40The MV meter be lower than 190J slightly.
A～f by table 12 is visible, and the value of A value or A/G brings the influence of HAZ flexible.The a of table 12 comprises the value of A value or A/G; Because all satisfy important document of the present invention; So demonstrate extremely good HAZ toughness, but its A value of b, c and d is little, so the miniaturization of bainite structure is insufficient; Though HAZ toughness minimum value is the value above 140J, MV is the value that is lower than 190J.E is because the A value is big, so the martensitic phase of hard generates, though HAZ toughness minimum value is the value above 150J, MV is the value that is lower than 190J.F is because the value of A/G is little, so the nucleus formation frequency of crystal boundary bainite reduces, thick bainite forms, though HAZ toughness minimum value is the value above 170J, MV is the value that is lower than 190J.
[embodiment 3]
In No.1～3,5,14 of the table 10 of said embodiment 2, among the No.31 of table 11 and the Ni.c of table 12, the d, (12.5mm * 32mm * 55mm) carries out the thermal cycling test same with embodiment 2 to extract test film from hot-rolled sheet.In this test film; For being equivalent to apart from the part of the dark t/4 position, surface of hot-rolled sheet; Implement EBSP (EBSD Electron Back-ScatteringPattern) and measure (the visual field: 200 μ m * 200 μ m), measure the median size that differs from the HAZ bainite structure of the big angle crystal boundary encirclement more than 15 ° by crystal orientation with method of bisector.The result is presented among table 13, Fig. 1.
[table 13]
| No. | The A value | The A/G value | HAZ bainite structure size (μ m) |
| 1 | 136 | 6824 | 21 |
| 2 | 138 | 8612 | 18 |
| 3 | 145 | 8080 | 15 |
| 5 | 151 | 8364 | 14 |
| 14 | 170 | 8945 | 11 |
| 31 | 152 | 6348 | 18 |
| |
120 | 7289 | 24 |
| d | 104 | 5329 | 26 |
Claims (3)
1. Plate Steel; It is characterized in that; Contain C:0.03～0.15 quality %; Below the Si:0.25 quality % and contain 0 quality %; Mn:1.0～2.0 quality %; Below the P:0.03 quality % but do not contain 0 quality %; Below the S:0.015 quality % but do not contain 0 quality %; Al:0.005～0.05 quality %; Ti:0.010～0.080 quality %; Nb:0.002～0.10 quality %; Ca:0.0005～0.010 quality % and N:0.002～0.020 quality %; Surplus is iron and unavoidable impurities
Contain the every 1mm of Ti nitride in what diameter of equivalent circle was lower than 0.05 μ m
2Have 5.0 * 10
6More than individual,
Contain the every 1mm of Ti nitride in diameter of equivalent circle 0.05～1.0 μ m
2Have 1.0 * 10
5More than individual,
And, contain the every 1mm of Ti nitride in what diameter of equivalent circle surpassed 1.0 μ m
2Exist below 5,
And the area ratio of the island martensite body of dark position for t/4 is below 5% apart from the surface, and wherein, t is a thickness of slab.
2. Plate Steel according to claim 1; It is characterized in that, also contain below the Ni:1.5 quality % but do not contain below 0 quality %, the Cu:1.5 quality % but do not contain below 0 quality %, the Cr:1.5 quality % but do not contain below 0 quality % and the Mo:1.5 quality % but do not contain the element more than a kind among the 0 quality %.
3. Plate Steel according to claim 1 and 2 is characterized in that, except that above-mentioned composition, also contains at least 1 group among following (a)～(c) crowd:
(a) below the V:0.1 quality % but do not contain 0 quality %;
(b) below the B:0.005 quality % but do not contain 0 quality %;
(c) below the Zr:0.02 quality % but do not contain below 0 quality %, the REM:0.02 quality % but do not contain among the 0 quality % more than a kind.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2008269894A JP5207914B2 (en) | 2008-10-20 | 2008-10-20 | Thick steel plate with excellent toughness of base metal and weld heat affected zone |
| JP2008-269894 | 2008-10-20 | ||
| JP2009169083A JP5340839B2 (en) | 2009-07-17 | 2009-07-17 | Steel sheet with excellent toughness of weld heat affected zone |
| JP2009-169083 | 2009-07-17 |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011102672758A Division CN102321842A (en) | 2008-10-20 | 2009-10-19 | Plate Steel |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN101724780A CN101724780A (en) | 2010-06-09 |
| CN101724780B true CN101724780B (en) | 2012-01-04 |
Family
ID=42218979
Family Applications (2)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2009102053093A Expired - Fee Related CN101724780B (en) | 2008-10-20 | 2009-10-19 | Thick steel plate |
| CN2011102672758A Pending CN102321842A (en) | 2008-10-20 | 2009-10-19 | Plate Steel |
Family Applications After (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011102672758A Pending CN102321842A (en) | 2008-10-20 | 2009-10-19 | Plate Steel |
Country Status (2)
| Country | Link |
|---|---|
| KR (1) | KR101119378B1 (en) |
| CN (2) | CN101724780B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101320220B1 (en) * | 2010-05-20 | 2013-10-29 | 가부시키가이샤 고베 세이코쇼 | Thick steel plate |
| JP5419820B2 (en) * | 2010-07-20 | 2014-02-19 | 新日鐵住金株式会社 | Rolled steel bar or wire rod for hot forging |
| JP5824434B2 (en) * | 2011-11-14 | 2015-11-25 | 株式会社神戸製鋼所 | Thick steel plate with excellent toughness in weld heat affected zone |
| JP6301805B2 (en) * | 2014-10-17 | 2018-03-28 | 株式会社神戸製鋼所 | Thick steel plate for tanks with excellent toughness of weld heat affected zone |
| JP2017078221A (en) * | 2015-10-21 | 2017-04-27 | 株式会社神戸製鋼所 | Steel plate and joined body |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4035990B2 (en) | 2001-12-13 | 2008-01-23 | Ｊｆｅスチール株式会社 | Super high heat input welding HAZ toughness and low yield ratio steel plate for building structure and method for producing the same |
| JP4507708B2 (en) | 2003-06-12 | 2010-07-21 | Ｊｆｅスチール株式会社 | Low yield ratio high strength high toughness steel sheet manufacturing method |
| JP4507747B2 (en) * | 2003-07-31 | 2010-07-21 | Ｊｆｅスチール株式会社 | Low yield ratio high strength high toughness steel pipe excellent in strain aging resistance and method for producing the same |
| JP4356949B2 (en) * | 2006-11-13 | 2009-11-04 | 株式会社神戸製鋼所 | Thick steel plate with excellent toughness in weld heat affected zone |
| JP4976905B2 (en) * | 2007-04-09 | 2012-07-18 | 株式会社神戸製鋼所 | Thick steel plate with excellent HAZ toughness and base metal toughness |
| JP4485561B2 (en) * | 2007-10-02 | 2010-06-23 | 株式会社神戸製鋼所 | High tensile steel plate for welding with excellent base metal toughness |
-
2009
- 2009-10-19 KR KR1020090099040A patent/KR101119378B1/en active IP Right Grant
- 2009-10-19 CN CN2009102053093A patent/CN101724780B/en not_active Expired - Fee Related
- 2009-10-19 CN CN2011102672758A patent/CN102321842A/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| KR101119378B1 (en) | 2012-03-06 |
| CN102321842A (en) | 2012-01-18 |
| KR20100044106A (en) | 2010-04-29 |
| CN101724780A (en) | 2010-06-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105492643B (en) | High strength cold rolled steel plate and its manufacture method | |
| CN101665887B (en) | Thick steel board | |
| CN101925685B (en) | High-strength thick steel products excellent in toughness and weldability, high-strength ultra-thick h shape steel and processes for manufacturing both | |
| CN107002198B (en) | High strength cold rolled steel plate and its manufacturing method | |
| JP5207914B2 (en) | Thick steel plate with excellent toughness of base metal and weld heat affected zone | |
| CN101343712B (en) | Heavy steel plate for high-heat energy input soldering with excellent shortness fissure spread stop character | |
| CN105940133B (en) | Wear-resistant steel plate and its manufacture method | |
| CN101285150B (en) | Heavy plate excellent in haz toughness and mother plate toughness | |
| CN105940134A (en) | High-strength cold-rolled steel sheet and method for manufacturing same | |
| CN101285159B (en) | Heavy plate excellent in haz toughness | |
| CN101787488B (en) | Steel material of a welding heat effect part with excellent toughness | |
| CN105102651B (en) | The Large Heat Input Welding high-strength steel sheet and its manufacture method of excellent in brittle-cracking propagation stopping characteristics | |
| JP5172391B2 (en) | Steel sheet with excellent toughness and uniform elongation of weld heat affected zone | |
| CN101182618B (en) | Tenacity excellent high intensity steel for welding heat influenced part | |
| CN102884217A (en) | High-strength thick steel plate with excellent drop weight characteristics | |
| JP6160574B2 (en) | High-strength hot-rolled steel sheet excellent in strength-uniform elongation balance and method for producing the same | |
| CN101724780B (en) | Thick steel plate | |
| CN101153372A (en) | Steel plate with excellent inhibition of welding heat affected section and manufacturing method of the same | |
| CN101363100B (en) | Thick steel plate for high heat input welding with excellent shear property | |
| CN101392352B (en) | Thick high tension steel plate for high heat energy input welding and production method thereof | |
| CN101210300A (en) | Toughness excellent steel plate of welding heat influence part in ultra-high heat input welding | |
| CN101205591A (en) | High-strength steel plate resistant to strength reduction resulting from stress relief annealing and excellent in weldability | |
| CN101760695B (en) | Thick steel plate | |
| CN101586220B (en) | High-tension steel plate with excellent toughness and endurance crack resistance for welding heat influence part | |
| JP2011021263A (en) | Steel plate excellent in weld heat affected zone toughness |
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 | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20120104 Termination date: 20201019 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |