CN110225988A - Ferrite-group stainless steel hot rolled steel plate and its manufacturing method - Google Patents

Ferrite-group stainless steel hot rolled steel plate and its manufacturing method Download PDF

Info

Publication number
CN110225988A
CN110225988A CN201880008313.8A CN201880008313A CN110225988A CN 110225988 A CN110225988 A CN 110225988A CN 201880008313 A CN201880008313 A CN 201880008313A CN 110225988 A CN110225988 A CN 110225988A
Authority
CN
China
Prior art keywords
rolling
ferrite
content
steel plate
stainless steel
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.)
Granted
Application number
CN201880008313.8A
Other languages
Chinese (zh)
Other versions
CN110225988B (en
Inventor
吉野正崇
藤泽光幸
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
JFE Steel Corp
JFE Engineering Corp
Original Assignee
NKK Corp
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 NKK Corp filed Critical NKK Corp
Publication of CN110225988A publication Critical patent/CN110225988A/en
Application granted granted Critical
Publication of CN110225988B publication Critical patent/CN110225988B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0221—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the working steps
    • C21D8/0226—Hot rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/004—Heat treatment of ferrous alloys containing Cr and Ni
    • 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
    • C22C38/60—Ferrous alloys, e.g. steel alloys containing lead, selenium, tellurium, or antimony, or more than 0.04% by weight of sulfur
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D6/00—Heat treatment of ferrous alloys
    • C21D6/02—Hardening by precipitation
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0205—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips of ferrous alloys
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D8/00—Modifying the physical properties by deformation combined with, or followed by, heat treatment
    • C21D8/02—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips
    • C21D8/0247—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment
    • C21D8/0263—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of plates or strips characterised by the heat treatment following hot rolling
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
    • C21D9/46—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for sheet metals
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/001—Ferrous alloys, e.g. steel alloys containing N
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/002—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
    • C22C38/004—Very low carbon steels, i.e. having a carbon content of less than 0,01%
    • 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/42—Ferrous alloys, e.g. steel alloys containing chromium with nickel with copper
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/44—Ferrous alloys, e.g. steel alloys containing chromium with nickel with molybdenum or tungsten
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/46—Ferrous alloys, e.g. steel alloys containing chromium with nickel with vanadium
    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C38/00—Ferrous alloys, e.g. steel alloys
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/48—Ferrous alloys, e.g. steel alloys containing chromium with nickel with niobium or tantalum
    • 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
    • C22C38/50—Ferrous alloys, e.g. steel alloys containing chromium with nickel with 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
    • C22C38/18—Ferrous alloys, e.g. steel alloys containing chromium
    • C22C38/40—Ferrous alloys, e.g. steel alloys containing chromium with nickel
    • C22C38/52—Ferrous alloys, e.g. steel alloys containing chromium with nickel with cobalt
    • 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
    • C22C38/54—Ferrous alloys, e.g. steel alloys containing chromium with nickel with boron
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
    • C21D2211/00—Microstructure comprising significant phases
    • C21D2211/005—Ferrite

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Heat Treatment Of Sheet Steel (AREA)
  • Heat Treatment Of Steel (AREA)

Abstract

The present invention provides the ferrite-group stainless steel hot rolled steel plate and its manufacturing method for having sufficient corrosion resistance and being able to suppress crackle of the punch press process at thick wall flange disk when.The ferrite-group stainless steel hot rolled steel plate, with as follows at being grouped as, contain C:0.001~0.020%, Si:0.05~1.00%, Mn:0.05~1.00%, P:0.04% or less, S:0.01% or less, Al:0.001~0.50%, N:0.001~0.020%, Cr:11.0~24.0%, Ni:0.01~2.00%, Nb:0.12~0.80% in terms of quality %, remainder is made of Fe and inevitable impurity, critical stress intensity factors KICFor 25MPam1/2More than.

Description

Ferrite-group stainless steel hot rolled steel plate and its manufacturing method
Technical field
The present invention relates to the ferrite-group stainless steel hot-rolled steels excellent suitable for the punch press process for forming ring flange etc. Plate and its manufacturing method.
Background technique
In recent years, the reinforcing of the relevant laws and regulations of the exhaust to automobile is being promoted, improving fuel efficiency becomes when business It is anxious.Therefore, the exhaust for using the exhaust generated by automobile engine as the air inlet of engine again is being promoted to follow again Ring (Exhaust Gas Recirculation, EGR) systematic difference.By engine generate exhaust by for reducing It is supplied again after the cooler for recycled exhaust gas of gas temperature to engine.When making exhaust cycle, gas leakage, each to be vented in order to prevent System unit is fastened via ring flange.The ring flange applied in such exhaust system component needs to have enough rigid Property.Therefore, always using the ring flange of heavy wall (such as plate thickness is 5mm or more) in such exhaust system component.
In the past, the ring flange of heavy wall used always ordinary steel.But for for passing through high temperature as egr system The ring flange of the component of exhaust, it is desirable that sufficient corrosion resistance.Therefore, to compared with ordinary steel excellent corrosion resistance it is stainless Steel, particularly coefficient of thermal expansion are smaller and be difficult to generate the application of the ferrite-group stainless steel of thermal stress and studied, and want strongly Seek (such as plate thickness is 5mm or more) ferrite series stainless steel plate that the plate thickness that can be used for the ring flange of heavy wall is big.
For such market demands, for example, being containing for 5.0~10.0mm Patent Document 1 discloses a kind of plate thickness Nb ferrite-group stainless steel coils of hot rolled has following composition in terms of quality %, by C:0.030% or less, Si:2.00% with Under, Mn:2.00% or less, P:0.050% or less, S:0.040% or less, Cr:10.00~25.00%, N:0.030% or less, Nb:0.01~0.80%, remainder are made of Fe and inevitable impurity, and hardness is adjusted to 190HV hereinafter, at 25 DEG C Charp impact value is adjusted to 20J/cm2More than.
Existing technical literature
Patent document
Patent document 1: Japanese Unexamined Patent Publication 2012-140688 bulletin
Summary of the invention
But the inventors of the present invention utilize crank pressure using the ferrite-group stainless steel coils of hot rolled recorded in patent document 1 Power machine punch press process at heavy wall flange disk shape, although as a result have enough charp impact values, sometimes in punching portion Plate thickness central portion generates apparent crackle, is unable to get defined flange disk shape, it is clear that be not enough to the flange applied to heavy wall Disk.In addition, coils of hot rolled disclosed in Patent Document 1 in order to obtain, needs being immersed in coiled material after batching in hot rolling In water and kept for 15 minutes or more, there is also projects in manufacturing and productivity.
It is an object of the invention to: the above subject is solved, provides with sufficient corrosion resistance and is able to suppress with bent The ferrite-group stainless steel hot rolled steel plate of crackle when handle press machine be shaped to the punch press process of the ring flange of heavy wall and its Manufacturing method.
The inventors of the present invention are studied in detail to solve project, as a result, it has been found that in order to be added using crank press etc. The biggish processing method of work speed in the case where not cracking punch press process at heavy wall ring flange, as long as making facing for steel plate Boundary's stress intensity factor (Threshold Stress Intensity Factor) KICBecome larger.Specifically, discovery passes through Make critical stress intensity factors KICFor 25MPam1/2More than, even if thus big using process velocity as crank press Processing method can also be effectively inhibited and be cracked when punch press process is at thick wall flange disk in punching end face portion, Neng Gouchong Divide the ring flange suitable for heavy wall.
The inventors of the present invention are studied in detail to solve project.The result found that utilizing crank press etc. The big processing method of process velocity by plate thickness be more than 5.0mm heavy wall steel plate in the case where not cracking punch press process at When the ring flange of heavy wall, processability not can be carried out accurate evaluation using the charp impact value used always in the past, but utilize The toughness evaluation index in slab field, i.e. critical stress intensity factors (Threshold Stress Intensity Factor) KICIt is able to carry out accurate evaluation.It is thought that the punching end due in sheet metal of the plate thickness less than 5.0mm, when due to processing Plastic deformation area near face is larger relative to plate thickness, therefore cannot entirely be arranged using the processing of fracture mechanics adjoint Forming phenomenon of rupture, in contrast, plate thickness be 5.0mm or more heavy wall steel plate in, when due to sufficiently meeting processing The plastic deformation area in the neighbouring portion in punching end face become sufficiently small small-scale yield situation relative to plate thickness, therefore being capable of benefit The phenomenon of rupture along with defined processing is handled with the quantitative target of fracture mechanics, i.e. stress intensity factor, especially can Enough utilize its critical value, i.e. critical stress intensity factors KICCarry out accurate evaluation.
Crackle the presence or absence of when the inventors of the present invention are to the ring flange for utilizing crank press punch press process established practice setting shape as a result, Generation and critical stress intensity factors KICRelationship carried out probe.Its result obtains following opinion: critical by making Stress strength factor KICFor 25MPam1/2More than, it can effectively inhibit in utilization crank press punch press process into heavy wall method It is cracked when blue disk in punching end face portion, the ring flange of heavy wall can be fully applicable to.
But also obtain following opinion: the ferrite-group stainless steel by being directed to proper composition, especially suitable control is by 3 The hot finishing that more than passage multi-pass is constituted (roll between heat on bodyguard) final 3 passages in process accumulation reduction ratio (= 100- (rolling of final plate thickness/final 3 passages start before plate thickness) × 100 [%]), to make the critical of hot rolled steel plate Stress strength factor KICIt improves.
The present invention is carried out based on the above opinion, and main idea is as follows.
[1] a kind of ferrite-group stainless steel hot rolled steel plate has as follows at being grouped as, in terms of quality %, contains C:0.001 ~0.020%, Si:0.05~1.00%, Mn:0.05~1.00%, P:0.04% or less, S:0.01% or less, Al:0.001 ~0.50%, N:0.001~0.020%, Cr:11.0~24.0%, Ni:0.01~2.00%, Nb:0.12~0.80% remain Remaining part point is made of Fe and inevitable impurity, critical stress intensity factors KICFor 25MPam1/2More than.
[2] a kind of ferrite-group stainless steel hot rolled steel plate has as follows at being grouped as, in terms of quality %, contains C:0.001 ~0.020%, Si:0.05~1.00%, Mn:0.05~1.00%, P:0.04% or less, S:0.01% or less, Al:0.001 ~0.50%, N:0.001~0.020%, Cr:13.0~24.0%, Ni:0.01~0.60%, Nb:0.12~0.80% remain Remaining part point is made of Fe and inevitable impurity, critical stress intensity factors KICFor 25MPam1/2More than.
[3] the ferrite-group stainless steel hot rolled steel plate according to above-mentioned [1] or [2], wherein as at being grouped as, with Quality % meter, further containing selected from Cu:0.01~1.50%, Mo:0.01~2.00%, W:0.01~0.20%, Co:0.01 It is one kind or two or more in~0.20%.
[4] the ferrite-group stainless steel hot rolled steel plate according to any one of above-mentioned [1]~[3], wherein as ingredient Composition, in terms of quality %, further containing selected from Ti:0.01~0.30%, V:0.01~0.20%, Zr:0.01~0.20%, REM:0.001~0.100%, B:0.0002~0.0025%, Mg:0.0005~0.0030%, Ca:0.0005~0.0030% In it is one kind or two or more.
[5] a kind of manufacturing method of ferrite-group stainless steel hot rolled steel plate is described in any one of above-mentioned [1]~[4] The manufacturing method of ferrite-group stainless steel hot rolled steel plate makes finish rolling in the hot-rolled process of finish rolling for carrying out 3 passages or more Final 3 passages are in 800~1100 DEG C of temperature range and make 25% or more the accumulation reduction ratios of above-mentioned final 3 passages.
Here, critical stress intensity factors KICRefer to that with fatigue precracking line be rolling right angle orientation, stress axis is that rolling is flat The mode of line direction takes the CT test film according to ASTM E399 from board width central portion, tested according to ASTM E399 and Obtained stress intensity factor.
According to the present invention, it obtains that there is sufficient corrosion resistance and be able to suppress to be shaped to heavy wall with crank press Ring flange punch press process when crackle excellent tenacity ferrite-group stainless steel hot rolled steel plate.
It should be noted that the sufficient corrosion resistance in the present invention refers to: the surface grinding that will be evaluated using #600 sand paper After polishing, carrying out brine spray cyclic test specified in the JIS H 8502 of 5 circulations in the steel plate for sealing end face portion (will (brine spray (5 mass %NaCl, 35 DEG C, be sprayed 2hr) → dry (60 DEG C, 4hr, relative humidity 40%) → wetting (50 DEG C, 2hr, relative humidity >=95%)) as 1 recycle test) when steel plate evaluation face rust area rate (=face of getting rusty Product/steel plate the gross area × 100 [%]) it is 25% or less.
In addition, the toughness of crackle when being able to suppress the punch press process for the ring flange for being shaped to heavy wall with crank press is excellent It is different to refer to: to be adopted in such a way that fatigue precracking line is rolling right angle orientation, stress axis is rolling parallel direction from board width central portion The CT test film according to ASTM E399 is taken, critical stress intensity factors K obtained from being tested according to ASTM E399ICFor 25MPa·m1/2More than.
Specific embodiment
Ferrite-group stainless steel hot rolled steel plate of the invention has as follows at being grouped as, and contains C:0.001 in terms of quality % ~0.020%, Si:0.05~1.00%, Mn:0.05~1.00%, P:0.04% or less, S:0.01% or less, Al:0.001 ~0.50%, N:0.001~0.020%, Cr:11.0~24.0%, Ni:0.01~2.00%, Nb:0.12~0.80% remain Remaining part point is made of Fe and inevitable impurity, critical stress intensity factors KICFor 25MPam1/2More than.
As preferred form, ferrite-group stainless steel hot rolled steel plate of the invention has as follows at being grouped as, with matter % meter is measured, C:0.001~0.020%, Si:0.05~1.00%, Mn:0.05~1.00%, P:0.04% or less, S are contained: 0.01% or less, Al:0.001~0.50%, N:0.001~0.020%, Cr:13.0~24.0%, Ni:0.01~0.60%, Nb:0.12~0.80%, remainder are made of Fe and inevitable impurity, critical stress intensity factors KICFor 25MPa m1/2More than.
Critical stress intensity factors KICRefer to that with fatigue precracking line be rolling right angle orientation, stress axis is rolling parallel direction Mode take the CT test film according to ASTM E399 from board width central portion, obtained from being tested according to ASTM E399 Stress intensity factor.
Hereinafter, the present invention is described in detail.
The inventors of the present invention to use the various ferrite-group stainless steel hot rolled steel plates of plate thickness 5.0mm using crank press rush The reason of cracking when cutting out the ring flange for the shape for being processed into the hole portion with diameter 30mm is studied in detail.Its result It was found that: it is orthogonal with punching direction near the plate thickness central portion of punching end face portion in the above-mentioned steel plate for producing crackle Direction generate small cracking, cracking development, to crack.
The generation and development of the small cracking and the relationship of material property is studied in detail in the inventors of the present invention.It is tied Fruit finds to reduce with the critical stress intensity factors of steel plate, and the development of small cracking has incidental trend.Therefore, it attempts Using various ferrite-group stainless steel hot rolled steel plate (plate thickness 5.0mm) punch press process at the ring flange, as a result, it has been found that by providing The obtained critical stress intensity factors of measuring method be 25MPam1/2It does not crack, is being lower than in above steel plate 25MPa·m1/2Steel plate in be easy to produce crackle.
Therefore, for the method progress to improving critical stress intensity factors in ferrite-group stainless steel hot rolled steel plate Research, the inventors of the present invention have carried out the probe of composition of steel and hot-rolled condition.It is as a result, it has been found that pass through the iron to proper composition Plain system stainless steel with especially carry out the finish rolling being made of multi-pass hot-rolled process final 3 passages 800~1100 DEG C temperature range and the accumulation reduction ratios of final 3 passages ((rolling of final plate thickness/final 3 passages starts=100- Preceding plate thickness) × 100 [%]) it is controlled for 25% or more mode, thus not only to surface part also to plate thickness central portion It has been efficiently directed into rolling strain, has as a result obtained 25MPam1/2Above critical stress intensity factors KIC。
It should be noted that the plate thickness of ferrite-group stainless steel hot rolled steel plate of the invention is not particularly limited, due to being desirable to It is enough in the plate thickness of the ring flange of heavy wall, therefore preferably 5.0mm or more.In addition, above-mentioned plate thickness is not particularly limited, preferably 15.0mm is hereinafter, more preferably 10.0mm or less.
Hereinafter, also effectively assigning rolling strain, steel to the plate thickness central portion of the steel plate after hot rolling to using the above method The critical stress intensity factors K of plate whole thicknessICThe reason of rising, is illustrated.
When being rolled to steel plate, steel plate anamorphic stretching since surface section.Therefore, in the case where reduction ratio is small, plate The deflection of thick central portion is small, hardly assigns rolling strain to plate thickness central portion.In addition, ferrite-group stainless steel has in heat The trend of the recovery of processing strain is easy to happen in rolling.Therefore, in the hot rolling carried out using the prior art, not due to reduction ratio Enough processing strain effectively can not be assigned to plate thickness central portion.In turn, the rolling being endowed is strained due to excessive in hot rolling Restore and eliminates and reduce.As a result, cannot get in the hot rolling carried out using the prior art defined critical stress intensity because Sub- KIC。
Therefore, the inventors of the present invention, which are directed in hot-rolled process, effectively and fully assigns rolling to the plate thickness central portion of steel plate The method of strain is started with from composition of steel and hot-rolling method these two aspects and is had made intensive studies.
Itself as a result, it has been found that from the viewpoint of hot-rolling method, by by final 3 passage management of hot finishing appropriate Then temperature range is rolled with biggish accumulation reduction ratio, so that rolling strain sufficiently and is effectively imparted to plate thickness Central portion.
But obtain following opinion: from the viewpoint of composition of steel, in the ferrite-group stainless steel for being practically free of Nb In, the recovery being easy to happen in hot rolling, therefore, the hot-rolling method proposed even with the inventors of the present invention also cannot get enough roll System answers variable density, cannot get defined critical stress intensity factors.
On the other hand, obtain following opinion: due to containing appropriate Nb ferrite-group stainless steel in, it is fine in hot rolling Nb Carbonitride Precipitation, the fine Nb carbonitride hinder the movement of dislocation, therefore proposed by using the inventors of the present invention Hot-rolling method can obtain higher rolling and answer variable density, at the same critical stress intensity as defined in obtaining in hot rolled steel plate because Son.
Obtain following opinion: in the present invention, by the ferrite-group stainless steel containing appropriate Nb by hot finishing Final 3 passage management in temperature range appropriate, then rolled with biggish accumulation reduction ratio, to inhibit to roll The recovery of strain, and rolling is strained to the central portion for sufficiently and being effectively imparted to plate thickness, it is strong to obtain defined limit stress Spend factor KIC。
Specifically, proposing following scheme: to the ferrite-group stainless steel of the Nb containing 0.12% or more by 3 passages Final 3 passages of the hot finishing process constituted above are in 800~1100 DEG C of temperature range and the accumulation pressure of final 3 passages The side that lower rate (=100- (rolling of final plate thickness/final 3 passages start before plate thickness) × 100 [%]) is 25% or more Formula is controlled, and hot rolling is carried out.
Next, being illustrated to ferrite-group stainless steel hot rolled steel plate of the invention at being grouped as.
Hereinafter, unless otherwise specified, the % of expression composition composition refers to quality %.
C:0.001~0.020%
If being more than 0.020% containing C, the reduction of the corrosion resistance of the reduction and weld part of processability becomes significant. From the viewpoint of corrosion resistance and processability, the fewer C content the better, but in order to make C content less than 0.001%, refining expends Time, in manufacture not preferably.Therefore range of the C content 0.001~0.020%.C content is preferably 0.003% or more, More preferably 0.004% or more.In addition, C content is preferably 0.015% hereinafter, more preferably 0.012% or less.
Si:0.05~1.00%
Si has the effect of being enriched in the oxide film thereon formed when welding and improves the corrosion resistance of weld part, and It is the element useful as the deoxidant element in steel making working procedure.These effects are obtained and the Si containing 0.05% or more, are contained It is bigger to measure its more effect.But if being more than 1.00% containing Si, the increase of the rolling load in hot-rolled process occurs Generation with significant oxide skin, in annealing operation because of the reduction of the pickling caused by steel plate surface layer forms Si enriched layer, The increase of surface defect, the rising of manufacturing cost are induced, it is thus not preferred.Therefore Si content is 0.05~1.00%.Si content Preferably 0.10% or more.In addition, Si content is preferably 0.60% hereinafter, more preferably 0.40% or less.
Mn:0.05~1.00%
Mn has the effect of improving the intensity of steel, in addition, also having the function of as deoxidier.The effect in order to obtain, Need the Mn containing 0.05% or more.But if Mn content is more than 1.00%, become the precipitation of the MnS of the starting point of corrosion It is promoted, corrosion resistance reduces.Therefore Mn content is 0.05~1.00%.Mn content is preferably 0.10% or more.In addition, Mn Content is preferably 0.50% hereinafter, more preferably 0.30% or less.
P:0.04% or less
P is the element inevitably contained in steel, but for corrosion resistance and the harmful element of processability, thus excellent Choosing is reduced as far as.In particular, processability significantly reduces due to solution strengthening if P content is more than 0.04%.Therefore, P Content is 0.04% or less.It is preferred that P content is 0.03% or less.
S:0.01% or less
The element that S and P also inevitably contain in steel, but because be harmful to corrosion resistance and processability Element and it is preferred that being reduced as far as.In particular, corrosion resistance significantly reduces if S content is more than 0.01%.Therefore, S Content is 0.01% or less.It is preferred that S content is 0.008% or less.More preferable S content is 0.003% or less.
Al:0.001~0.50%
Al is effective deoxidier.Further, since the affinity ratio Cr of Al and N is strong, therefore when N invades weld part, make N It is precipitated in the form of Al nitride rather than in the form of Cr nitride, has the effect of inhibiting sensitization.These effects are by containing There is 0.001% or more Al and obtains.But if penetration when welding reduces, welding containing the Al for having more than 0.50% Workability reduces, thus not preferred.Therefore range of the Al content 0.001~0.50%.Al content be preferably 0.20% hereinafter, More preferably 0.10% or less.
N:0.001~0.020%
If N content is more than 0.020%, the reduction of the corrosion resistance of the reduction and weld part of processability becomes significant. From the viewpoint of corrosion resistance, the lower N content the better, in order to make N content be reduced to less than 0.001%, needs prolonged Refining, leads to the rising of manufacturing cost and the reduction of productivity, thus not preferred.Therefore, N content is 0.001~0.020% Range.N content is preferably 0.003% or more, and more preferably 0.005% or more.In addition, N content be preferably 0.015% hereinafter, More preferably 0.012% or less.
Cr:11.0~24.0%
Cr is to the most important element of corrosion resistance for ensuring stainless steel.When its content is less than 11.0%, in automobile exhaust It cannot get sufficient corrosion resistance in atmosphere.On the other hand, when being more than 24.0% containing Cr, due to generating σ (Sigma) Xiang Erren Property is substantially reduced, and is unable to get defined critical stress intensity factors in the present invention.Therefore Cr content is 11.0~24.0% Range.Cr content is preferably 13.0% or more, more preferably 14.0% or more, further preferably 16.0% or more, more into One step is preferably 17.0% or more.In addition, Cr content be preferably 21.5% hereinafter, more preferably 20.0% hereinafter, further it is excellent It is selected as 18.5% or less.
Ni:0.01~2.00%
Ni is the element for improving the corrosion resistance of stainless steel, is that the corruption of active dissolution occurs not forming passive state envelope Lose the element for inhibiting corrosion to carry out in environment.In addition, Ni is strong austenite forming element, has and inhibit to generate in weld part Ferrite, inhibit because Cr carbonitride precipitation caused by sensitization effect.The effect is and the Ni containing 0.01% or more It obtains, the content of Ni is more, and the effect is higher.But if Ni content is more than 2.00%, not only processability is reduced, Er Qierong It is also easy to produce stress corrosion cracking (SCC).Further, since Ni is expensive element, thus the increase of the content of Ni will lead to manufacture at This increase, it is thus not preferred.Therefore Ni content is 0.01~2.00%.Ni content is preferably 0.05% or more, more preferably 0.10% or more.In addition, Ni content is preferably 1.00% hereinafter, more preferably 0.60% hereinafter, further preferably 0.50% Hereinafter, being still more preferably 0.45% or less.
Nb:0.12~0.80%
Nb is precipitated in conjunction with C or N and in the form of Nb carbonitride in hot-rolled process.The Nb carbonitride of precipitation has The movement of pinning dislocation, the effect for inhibiting the rolling strain assigned by hot rolling to eliminate by recovery.The recovery in hot rolling is prolonged as a result, Late, it is able to suppress the reduction that variable density is answered because the rolling caused by excessively restoring occurs.It is obtained when containing 0.12% or more Nb Said effect.But if Nb content is more than 0.80%, due to generation Laves phase, reduce toughness sometimes instead, and Rolling load in hot rolling obviously rises, and therefore, it is difficult to apply hot-rolling method provided by the invention.Therefore Nb content 0.12~ 0.80% range.Nb content is preferably 0.15% or more, and more preferably 0.20% or more.In addition, Nb content is preferably 0.75% hereinafter, more preferably 0.60% or less.
The present invention is a kind of ferrite-group stainless steel, which is characterized in that containing above-mentioned essential component and remainder is by Fe It is constituted with inevitable impurity.In addition, as needed, a kind in Cu, Mo, W and Co can be contained in following ranges Or two or more or/and it is one kind or two or more in Ti, V, Zr, REM, B, Mg and Ca.
Cu:0.01~1.50%
Cu is to improve spy to the corrosion resistance of base material and weld part when making in aqueous solution or being attached with weakly acidic water droplet Not effective element.The effect containing 0.01% or more by obtaining, and Cu content is more, and the effect is higher.But if contain Having Cu is more than 1.50%, then hot-workability reduces and induces surface defect sometimes.In addition, the deoxygenated skin after annealing sometimes also becomes It obtains difficult.Therefore contain Cu when, Cu content preferably 0.01~1.50% range.Cu content is more preferably 0.10% or more, Further preferably 0.30% or more.In addition, Cu content is more preferably 0.60% hereinafter, further preferably 0.45% or less.
Mo:0.01~2.00%
Mo is the element for significantly improving the corrosion resistance of stainless steel.The effect is obtained by containing 0.01% or more, The more effects of content more improve.But if Mo content is more than 2.00%, rolling load when hot rolling becomes larger and makes sometimes The property made reduces, or the excessive rising of armor plate strength occurs.In addition, largely containing since Mo is expensive element Manufacturing cost can be made to increase.When therefore, containing Mo, Mo content is preferably 0.01~2.00%.Mo content is more preferably 0.10% More than.In addition, Mo content is more preferably 1.40% or less.But due in the steel containing Ti Mo also have and reduce toughness Effect, therefore when containing 0.15% or more Ti, Mo content is preferably 0.30~1.40% or less.Contain 0.15% or more When Ti, Mo content is more preferably 0.40% or more.In addition, containing 0.15% or more Ti when, Mo content is more preferably 0.90% Below.
W:0.01~0.20%
W is same as Mo to be had the effect of improving corrosion resistance.The effect is obtained and the W containing 0.01% or more.But It is that when being more than 0.20% containing W, intensity rises, leads to the reduction of manufacturing because of rolling load increase etc. sometimes.Therefore, contain When having W, W content preferably 0.01~0.20% range.W content is more preferably 0.05% or more.In addition, W content is more preferable It is 0.15% or less.
Co:0.01~0.20%
Co is the element for improving toughness.The effect is obtained and the Co containing 0.01% or more.On the other hand, if Co content is more than 0.20%, then processability reduces sometimes.When therefore, containing Co, Co content preferably 0.01~0.20% model It encloses.
Ti:0.01~0.30%
Ti be with the affinity of C and N be higher than Cr element, in the form of carbide or nitride be precipitated, have inhibit because The effect of sensitization caused by the precipitation of Cr carbonitride.The effect in order to obtain needs the Ti containing 0.01% or more.But If Ti content is more than 0.30%, good surface texture is unable to get because of the excessive precipitation of TiN sometimes.Therefore, contain When Ti, Ti content preferably 0.01~0.30% range.Ti content is more preferably 0.03% or more, further preferably 0.10% or more.In addition, Ti content is more preferably 0.20% hereinafter, further preferably 0.15% or less.
V:0.01~0.20%
V and C, N form carbonitride, inhibit sensitization when welding and improve the corrosion resistance of weld part.The effect is logical V content is crossed to obtain for 0.01% or more.On the other hand, if V content is more than 0.20%, processability and toughness are obvious sometimes It reduces.Therefore, V content is preferably 0.01~0.20%.V content is more preferably 0.05% or more.In addition, V content is more preferably 0.15% or less.
Zr:0.01~0.20%
Zr has the effect of inhibiting sensitization in conjunction with C, N.The effect is obtained and the Zr containing 0.01% or more.Separately On the one hand, if being more than 0.20% containing Zr, processability is substantially reduced sometimes.When therefore, containing Zr, Zr content preferably exists 0.01~0.20% range.Zr content is more preferably 0.10% or less.
REM:0.001~0.100%
REM (Rare Earth Metals: rare earth metal) has the effect of raising oxidative resistance, inhibits the oxygen of weld part Change the formation that envelope (welding tempering colour) formed and inhibited the Cr-depleted region domain immediately below oxide film thereon.The effect is by containing 0.001% or more REM and obtain.On the other hand, if being more than 0.100% containing REM, acid when making cold rolled annealed sometimes The manufacturings such as washing property reduce.When therefore, containing REM, REM content preferably 0.001~0.100% range.REM content is more excellent It is selected as 0.050% or less.
B:0.0002~0.0025%
B is to the improvement deep drawing resistance to effective element of secondary processing brittleness after molding.The effect is by making the content of B 0.0002% or more and obtain.On the other hand, if crossing 0.0025% containing B ultrasound, processability and toughness are reduced sometimes.Cause This, when containing B, B content preferably 0.0002~0.0025% range.B content is more preferably 0.0003% or more.In addition, B Content is more preferably 0.0006% or less.
Mg:0.0005~0.0030%
Mg is to improve the equiaxial crystal ratio of steel billet, to the effective element of the raising of processability, toughness.The effect is by containing 0.0005% or more Mg and obtain.On the other hand, if Mg content is more than 0.0030%, make the surface texture of steel sometimes Deteriorate.When therefore, containing Mg, Mg content preferably 0.0005~0.0030% range.Mg content is more preferably 0.0010% More than.In addition, Mg content is more preferably 0.0020% or less.
Ca:0.0005~0.0030%
Ca is that have the effect of making smelting and field trash miniaturization that when continuously casting generates, particularly to preventing from continuously casting The effective ingredient of the blocking of nozzle in making.Its effect is obtained and the Ca containing 0.0005% or more.But if contain Ca is more than 0.0030%, then reduces corrosion resistance because generating CaS sometimes.When therefore, containing Ca, Ca content preferably exists 0.0005~0.0030% range.Ca content is more preferably 0.0015% hereinafter, further preferably 0.0010% or less.
Critical stress intensity factors KIC: 25MPam1/2More than
Ferrite-group stainless steel hot rolled steel plate of the invention can pass through critical stress intensity factors KICFor 25MPam1/2 Crackle when punch press process to inhibit the ring flange for being shaped to heavy wall with crank press above.Critical stress intensity factors KIC Preferably 30MPam1/2More than, more preferably 35MPam1/2More than, further preferably 40MPam1/2More than.It should say Bright, the ring flange of heavy wall is not particularly limited, such as can enumerate the ring flange of plate thickness 5.0mm or more.As above-mentioned ring flange, example Such as the ring flange of preferred 5.0~15.0mm of plate thickness, the ring flange of more preferable 5.0~10.0mm of plate thickness.
Next, being illustrated to the manufacturing method of ferrite-group stainless steel hot rolled steel plate of the invention.It should be noted that In the following description, unless otherwise specified, temperature is just the table with steel billet, the hot rolled steel plate of the measurements such as land surface pyrometer etc. Face temperature.
Ferrite-group stainless steel hot rolled steel plate of the invention is by using the steel billet formed with mentioned component, by roughing Make the rolling of final 3 passages of finish rolling at 800~1100 DEG C of temperature range in the hot rolling constituted with finish rolling more than 3 passages And makes 25% or more the accumulation reduction ratio of final 3 passages and obtain.
Firstly, using method well known to converter, electric furnace, vacuum melting furnace etc. to be made of mentioned component the molten steel that constitutes into Steel billet material (steel billet) is made by continuous metal cast process or ingot casting-cogging method in row melting.
The steel billet is heated 1~24 hour with 1100~1250 DEG C, or without heating and directly for heat after casting It rolls.In the present invention, the roughing aspect not to be particularly limited to, but the preparatory feelings for effectively destroying cast sturcture before hot finishing It under condition, plays a significant role, can be expected through the metal structure after hot rolling to the miniaturization of the crystal grain in hot finishing later It miniaturize and further increases toughness, therefore preferably make 65% or more accumulation reduction ratio in roughing.Thereafter, pass through hot essence It is rolled down to regulation plate thickness, so that temperature range of the rolling of final 3 passages of finish rolling at 800~1100 DEG C, presses accumulation The mode that lower rate is 25% or more carries out.
The rolling temperature range of final 3 passages of hot finishing: 800~1100 DEG C
The accumulation reduction ratio of final 3 passages of hot finishing: 25% or more
In order to obtain defined critical stress intensity factors after hot rolling, need through final 3 passages to hot finishing Rolling temperature and accumulation reduction ratio carry out suitable control come inhibit rolling in excessive recovery, simultaneously effective to plate thickness Central portion assigns rolling strain.
It is strained to also assign enough rollings to plate thickness central portion, needs to make the rolling of final 3 passages of hot finishing Range of the temperature at 800~1100 DEG C, and make accumulation reduction ratio (=100- (the final plate thickness/3 final of final 3 passages The rolling of passage start before plate thickness) × 100 [%]) and be 25% or more, prevent by final 3 passages assign rolling strain because Restore and eliminate, simultaneously effective assigns rolling strain to plate thickness center.
When the accumulation reduction ratio of final 3 passages of hot finishing is less than 25%, effectively plate thickness central portion can not be assigned Rolling strain, therefore it is unable to get defined critical stress intensity factors.Therefore, make the accumulation reduction ratio of final 3 passages 25% or more.It is preferred that accumulation reduction ratio is 30% or more.Further preferably accumulation reduction ratio is 35% or more.It should be noted that tired The upper limit of product reduction ratio is not particularly limited, if keeping accumulation reduction ratio excessive, rolling load rises sometimes and manufacturing drops It is low, therefore preferably 60% or less.
When making the rolling temperature of final 3 passages of hot finishing less than 800 DEG C, along with the reduction of steel billet temperature, rolling Load obviously rises, thus not preferred in manufacture.On the other hand, if the rolling temperature of final 3 passages is more than 1100 DEG C, then the rolling assigned by rolling is strained to be eliminated because of excessive recovery, is unable to get defined critical stress intensity factors.Cause This, range of the rolling temperature of final 3 passages at 800~1100 DEG C.It is preferred that the rolling temperature of final 3 passages 800~ 1050 DEG C of range.Range of the rolling temperature of more preferable final 3 passages at 850~1000 DEG C.
It should be noted that it is negative to apply excessive rolling in the specific passage in final 3 passages of hot finishing in order to prevent Lotus preferably makes 950~1100 DEG C of rolling temperature range of the 1st passage in final 3 passages, makes then the 1st passage The rolling temperature range of the 2nd passage carried out is 925~1075 DEG C, makes the 3rd passage that then the 2nd passage carries out Rolling temperature range is 875~1050 DEG C.
In addition, the manufacturing method of ferrite-group stainless steel hot rolled steel plate of the invention is characterized in that: by 3 passages with After controlling temperature range in final 3 passages of the hot finishing of upper composition, apply biggish pressure.If in 4 final roads Apply the rolling of biggish pressure, even identical accumulation reduction ratio in more than secondary, reduction ratio is also scattered in each passage, Therefore the strain imparting in plate thickness center is become inadequate, and the accumulation shipping time between each passage increases, therefore encourages Recovery during transporting between each passage, the effect for straining imparting reduce, it is difficult to obtain defined critical stress intensity factors.Separately On the one hand, if make finish rolling rolling temperature and accumulation reduction ratio control finally 2 passages hereinafter, if in order at 2 Carried out in passage accumulation 25% or more reduction ratio big pressure, there are rolling load obviously rise and manufacturing reduce the case where, It is thus not preferred.Therefore, to final 3 of finish rolling in the manufacturing method of ferrite-group stainless steel hot rolled steel plate of the invention The rolling temperature and accumulation reduction ratio of passage are controlled.
It should be noted that in the manufacturing method of ferrite-group stainless steel hot rolled steel plate of the invention, it is important that hot essence The rolling temperature and accumulation reduction ratio for the 3 final passages rolled are controlled, as long as finish rolling more than 3 passages, so that it may To carry out the finish rolling of any passage, but if maximum road number is more than 15 passages, then due to increasing with the frequency of exposure of roll and It is easy to happen the reduction of steel billet temperature, in order to maintain steel billet temperature within the scope of predetermined temperature, exists and needs from outside Heating etc. cause manufacturing reduction or manufacturing cost increase the case where, therefore, maximum road number be preferably 15 passages with Under.More preferably up to road number is 10 passages or less.
The cooling of steel plate is carried out after hot finishing, then carry out steel plate batches processing, and hot rolled strip is made.It is rolled up in the present invention When taking temperature to be not particularly limited, but making coiling temperature more than 450 DEG C and less than 500 DEG C, occur sometimes because of 475 DEG C of embrittlement Embrittlement.Therefore, coiling temperature is preferably 450 DEG C or less or 500 DEG C or more.If carrying out carbonated drink cooling etc. after final rolling to add Quickly cooling but after, carry out batching processing at 450 DEG C or less, then rolling caused by capable of further suppressing because of the recovery after batching strain Elimination, thus more preferably.
It should be noted that can carry out hot rolled plate annealing for the hot rolled steel plate obtained by the present invention and hot-roll annealing is made Steel plate.Due to excellent tenacity, the hot rolled plate being able to carry out on continuous annealing production line moves back hot rolled steel plate provided by the invention Fire, it is previous to worry to be broken as caused by low tenacity and avoid continuous annealing production line.In addition, after obtained hot-roll annealing steel plate It carries out cold rolling and cold-reduced sheet annealing also has no relations.
Embodiment
Hereinafter, by embodiment, the present invention is described in detail.
It will be true using the converter and strong mixing of capacity 150ton with the stainless molten steel of chemical composition shown in table 1 The refining of empty oxygen decarbonisation (SS-VOD) carries out melting, and the steel of width 1000mm, thickness 200mm are made up of continuously casting Base.After the steel billet is heated 1hr at 1200 DEG C, as hot rolling, carry out that about 40mm is made using the reversible roughing of 3 sections of bases Steel plate, the finish rolling for be made of 7 passages then according to the condition recorded in table 2 final 3 passages (the 5th passage, 6th passage, the 7th passage) hot rolled steel plate is made.
Following evaluation is carried out to obtained hot rolled steel plate.
(1) critical stress intensity factors KICEvaluation
It is adopted in such a way that fatigue precracking line is rolling right angle orientation, stress axis is rolling parallel direction from board width central portion Take the CT test film according to ASTM E399.For the test film, critical stress intensity factors K is found out according to ASTME399IC.It will Critical stress intensity factors is 25MPam1/2It is evaluated as qualification above, 25MPam will be less than1/2It is evaluated as unqualified.
(2) evaluation of corrosion resistance
The test film that 60 × 100mm is taken from obtained hot rolled steel plate is ground using the surface that #600 sand paper will be evaluated Production seals the test film of end face portion after grinding and polishing light, for brine spray cyclic test specified in JIS H 8502.Salt water Nebulisation cycle test be with brine spray (5 mass %NaCl, 35 DEG C, spraying 2hr) → dry (60 DEG C, 4hr, relative humidity 40%) → wetting (50 DEG C, 2hr, relative humidity >=95%) carries out 5 circulations as 1 circulation.To 5 circulations of implementation The evaluation face of test film after brine spray cyclic test carries out photograph taking, by image analysis come the evaluation of measurement test piece The rust area in face, calculating scale rate by the ratio with the test film gross area, ((rust area/test film in test film is total Area) × 100 [%]).10% or less scale rate is especially excellent corrosion resistance and is evaluated as qualified (◎), will be more than 10% And it is evaluated as qualified (zero) for 25% or less, it will be more than 25% to be evaluated as unqualified (×).
Test result and hot-rolled condition are shown in table 2 together.
Composition of steel, hot-rolled condition meet No.1~22 of the scope of the present invention, 29~33 by defined hot rolling to steel Rolling strain is fully imparted in plate, has as a result obtained defined critical stress intensity factors.In addition, to obtained hot-rolled steel The corrosion resistance of plate is evaluated, and as a result confirmed that scale rate is 25% hereinafter, having sufficient corrosion resistance.
No.2,4,6,7,9 especially with steel B, D, F, G, I containing Mo and the No.5 using steel E and H containing Cu With 8 and steel M, N and O for having used Cr content high No.13~15 in, it is 10% below more excellent for having obtained scale rate Corrosion resistance.
It is more than the scope of the present invention in the rolling temperature of the 5th passage (the 3rd passage since final passage) No.23 and the 5th passage and the rolling temperature of the 6th passage (the 2nd passage since final passage) are more than the present invention Range No.25 in, although being rolled with defined accumulation reduction ratio, due to rolling temperature be excessively high temperature, because This occur by rolling assign processing strain excessive recovery, as a result do not obtain after hot rolling as defined in critical stress intensity because Son.In No.24 of the accumulation reduction ratio of final 3 passages lower than the scope of the present invention, the imparting for rolling strain is insufficient, knot Fruit does not obtain defined critical stress intensity factors after hot rolling.
In No.26 of the rolling temperature of the 5th passage and the 6th passage lower than the scope of the present invention, due to rolling temperature Degree is too low temperature, therefore rolling load obviously rises, when the rolling of final 7th passage is implemented because load has been more than dress It sets allowed band and cannot complete to roll, defined evaluation can not be carried out.
In the No.27 of steel R for using Nb content being more than the scope of the present invention, has occurred in hot rolling and analysed by Laves phase Apparent toughness caused by out reduces, and does not obtain defined critical stress intensity factors.
In using No.28 of the Nb content lower than the steel S of the scope of the present invention, due to there is no that the Nb carbon nitrogen of sufficient amount is precipitated Compound, therefore the excessive recovery in hot rolling has occurred, do not obtain defined critical stress intensity factors.
In using No.34 of the Cr content lower than the steel Y of the scope of the present invention, since Cr content is insufficient, without To desired corrosion resistance.
In the No.35 of steel Z for using Cr content being more than the scope of the present invention, σ phase is precipitated because containing excessive Cr, Therefore the reduction that apparent toughness has occurred, is unable to get defined critical stress intensity factors.
Industrial availability
By the punch press process of the ferrite-group stainless steel hot rolled steel plate that the present invention obtains carried out using crank press It is especially excellent, particularly suitable for manufactured, required by using crank press or the punch press process of other methods etc. compared with The ring flange etc. of the heavy wall of high processability and corrosion resistance.

Claims (5)

1. a kind of ferrite-group stainless steel hot rolled steel plate, have as follows at being grouped as, in terms of quality % containing C:0.001~ 0.020%, Si:0.05~1.00%, Mn:0.05~1.00%, P:0.04% or less, S:0.01% or less, Al:0.001~ 0.50%, N:0.001~0.020%, Cr:11.0~24.0%, Ni:0.01~2.00%, Nb:0.12~0.80%, it is remaining Part is made of Fe and inevitable impurity,
Critical stress intensity factors KICFor 25MPam1/2More than.
2. a kind of ferrite-group stainless steel hot rolled steel plate, have as follows at being grouped as, in terms of quality % containing C:0.001~ 0.020%, Si:0.05~1.00%, Mn:0.05~1.00%, P:0.04% or less, S:0.01% or less, Al:0.001~ 0.50%, N:0.001~0.020%, Cr:13.0~24.0%, Ni:0.01~0.60%, Nb:0.12~0.80%, it is remaining Part is made of Fe and inevitable impurity,
Critical stress intensity factors KICFor 25MPam1/2More than.
3. ferrite-group stainless steel hot rolled steel plate according to claim 1 or 2, wherein as at being grouped as, with quality % Meter, further containing selected from Cu:0.01~1.50%, Mo:0.01~2.00%, W:0.01~0.20%, Co:0.01~ It is one kind or two or more in 0.20%.
4. ferrite-group stainless steel hot rolled steel plate described in any one of claim 1 to 3, wherein as at being grouped as, In terms of quality %, further containing selected from Ti:0.01~0.30%, V:0.01~0.20%, Zr:0.01~0.20%, REM: 0.001~0.100%, B:0.0002~0.0025%, Mg:0.0005~0.0030%, in Ca:0.0005~0.0030% It is one kind or two or more.
5. a kind of manufacturing method of ferrite-group stainless steel hot rolled steel plate, is ferrite according to any one of claims 1 to 4 It is the manufacturing method of stainless steel hot rolled steel plate, in the hot-rolled process of finish rolling for carrying out 3 passages or more, makes final the 3 of finish rolling A passage makes 25% or more the accumulation reduction ratio of final 3 passages at 800~1100 DEG C of temperature range.
CN201880008313.8A 2017-01-26 2018-01-12 Hot rolled ferritic stainless steel sheet and method for producing same Active CN110225988B (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP2017012545 2017-01-26
JP2017-012545 2017-01-26
PCT/JP2018/000559 WO2018139207A1 (en) 2017-01-26 2018-01-12 Ferrite stainless hot-rolled steel sheet and production method therefor

Publications (2)

Publication Number Publication Date
CN110225988A true CN110225988A (en) 2019-09-10
CN110225988B CN110225988B (en) 2021-09-07

Family

ID=62979289

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201880008313.8A Active CN110225988B (en) 2017-01-26 2018-01-12 Hot rolled ferritic stainless steel sheet and method for producing same

Country Status (7)

Country Link
US (1) US20200002779A1 (en)
EP (1) EP3556880A4 (en)
JP (1) JP6384640B1 (en)
KR (1) KR102274976B1 (en)
CN (1) CN110225988B (en)
MX (1) MX2019008874A (en)
WO (1) WO2018139207A1 (en)

Families Citing this family (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3385403B1 (en) 2016-02-08 2020-01-01 JFE Steel Corporation High-strength seamless stainless steel pipe for oil country tubular goods and method of manufacturing high-strength seamless stainless steel pipe
US11261512B2 (en) * 2016-09-02 2022-03-01 Jfe Steel Corporation Ferritic stainless steel
KR102234326B1 (en) 2016-09-02 2021-03-30 제이에프이 스틸 가부시키가이샤 Ferritic stainless steel
WO2018116792A1 (en) * 2016-12-21 2018-06-28 Ｊｆｅスチール株式会社 Ferritic stainless steel
JP6384636B1 (en) 2017-01-13 2018-09-05 Ｊｆｅスチール株式会社 High strength stainless steel seamless pipe and method for manufacturing the same
US11306369B2 (en) 2017-02-24 2022-04-19 Jfe Steel Corporation High-strength stainless steel seamless pipe for oil country tubular goods, and method for producing same
JP6274372B1 (en) 2017-03-30 2018-02-07 Ｊｆｅスチール株式会社 Ferritic stainless steel
KR102337567B1 (en) * 2017-05-26 2021-12-08 제이에프이 스틸 가부시키가이샤 Ferritic stainless steel
CN113614269B (en) * 2019-03-26 2022-10-25 杰富意钢铁株式会社 Ferritic stainless steel sheet and method for producing same
CN115466901B (en) * 2022-06-15 2023-05-26 福建青拓特钢技术研究有限公司 Ultra-pure ferrite stainless steel with low molybdenum and no sigma phase precipitation for ball pen head and production method thereof

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001181798A (en) * 1999-12-20 2001-07-03 Kawasaki Steel Corp Hot rolled ferritic stainless steel sheet excellent in bendability, its manufacturing method, and method of manufacturing for cold rolled steel sheet
CN104769144A (en) * 2012-10-30 2015-07-08 新日铁住金不锈钢株式会社 Ferritic stainless steel sheet having excellent heat resistance
CN106133166A (en) * 2014-03-26 2016-11-16 新日铁住金不锈钢株式会社 Ferrite-group stainless steel rolled plate and its manufacture method and flange components

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH08199237A (en) * 1995-01-25 1996-08-06 Nisshin Steel Co Ltd Production of hot rolled ferritic stainless steel strip excellent in toughness at low temperature
JP3518117B2 (en) * 1995-12-27 2004-04-12 Ｊｆｅスチール株式会社 Method for producing hot-rolled high Cr ferritic stainless steel sheet with smooth surface
JP4400058B2 (en) * 2003-02-13 2010-01-20 Ｊｆｅスチール株式会社 Ferritic stainless steel welded pipe with excellent spinning processability
JP5196807B2 (en) * 2007-02-26 2013-05-15 新日鐵住金ステンレス株式会社 Ferritic stainless steel sheet excellent in formability with low roughness of processing surface and method for producing the same
JP5262029B2 (en) * 2007-09-11 2013-08-14 Ｊｆｅスチール株式会社 Ferritic stainless steel plate with excellent stretch flangeability
JP5737952B2 (en) 2011-01-05 2015-06-17 日新製鋼株式会社 Nb-containing ferritic stainless steel hot rolled coil and manufacturing method
TWI548757B (en) * 2013-03-14 2016-09-11 新日鐵住金不銹鋼股份有限公司 Ferritic stainless steel sheet which is minimally strengthened after aging treatment and method of manufacturing the same
US10385429B2 (en) * 2013-03-27 2019-08-20 Nippon Steel & Sumikin Stainless Steel Corporation Hot-rolled ferritic stainless-steel plate, process for producing same, and steel strip
JP5918796B2 (en) * 2014-03-28 2016-05-18 新日鐵住金ステンレス株式会社 Ferritic stainless hot rolled steel sheet and steel strip with excellent toughness
US20190226045A1 (en) * 2016-10-17 2019-07-25 Jfe Steel Corporation Hot-rolled and annealed ferritic stainless steel sheet and method for manufacturing the same

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2001181798A (en) * 1999-12-20 2001-07-03 Kawasaki Steel Corp Hot rolled ferritic stainless steel sheet excellent in bendability, its manufacturing method, and method of manufacturing for cold rolled steel sheet
CN104769144A (en) * 2012-10-30 2015-07-08 新日铁住金不锈钢株式会社 Ferritic stainless steel sheet having excellent heat resistance
CN106133166A (en) * 2014-03-26 2016-11-16 新日铁住金不锈钢株式会社 Ferrite-group stainless steel rolled plate and its manufacture method and flange components

Also Published As

Publication number Publication date
JPWO2018139207A1 (en) 2019-01-31
US20200002779A1 (en) 2020-01-02
MX2019008874A (en) 2019-09-18
WO2018139207A1 (en) 2018-08-02
EP3556880A4 (en) 2019-12-04
JP6384640B1 (en) 2018-09-05
EP3556880A1 (en) 2019-10-23
KR20190102028A (en) 2019-09-02
CN110225988B (en) 2021-09-07
KR102274976B1 (en) 2021-07-07

Similar Documents

Publication Publication Date Title
CN110225988A (en) Ferrite-group stainless steel hot rolled steel plate and its manufacturing method
US10000824B2 (en) Material for cold-rolled stainless steel sheet and production method therefor
KR102201004B1 (en) Ferritic stainless steel hot rolled annealed steel sheet and manufacturing method thereof
CN107709592B (en) Ferrite series stainless steel plate and its manufacturing method
JP6432720B1 (en) Ferritic stainless steel hot rolled annealed steel sheet and method for producing the same
TWI546389B (en) Fat iron stainless steel plate
CN107429360B (en) The manufacturing method of steel plate for tanks and steel plate for tanks
TWI605134B (en) Fertilizer-grained stainless steel hot-rolled steel sheet and hot-rolled annealing sheet, and methods for producing the same
CN110295320A (en) A kind of big wall thickness X52MS acid-resistant pipeline steel plate and its manufacturing method of the production of LF-RH refinery practice
EP3093362B1 (en) Ferritic stainless steel and method for producing same
CN107532259A (en) Martensitic stain less steel
CN110747391A (en) Cold-rolled ultrahigh-strength steel with excellent elongation and preparation method thereof
JP6411881B2 (en) Ferritic stainless steel and manufacturing method thereof
JP2009079255A (en) High-tensile-strength cold-rolled steel sheet and method for manufacturing the same
JP6304469B1 (en) Ferritic stainless steel hot rolled annealed steel sheet and method for producing the same
CN110088321A (en) Steel plate
CN111424221B (en) Stainless steel plate for lamination and manufacturing method thereof
TWI841339B (en) Steel plate and method for manufacturing the same
CN107557669A (en) Inexpensive high formability energy hot-dip galvanizing sheet steel and preparation method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant