US2006243356A1PendingUtilityA1
Austenite-type stainless steel hot-rolling steel material with excellent corrosion resistance, proof-stress, and low-temperature toughness and production method thereof
Est. expiryFeb 2, 2025(expired)· nominal 20-yr term from priority
C22C 38/04C22C 38/002C22C 38/42C22C 38/001C22C 38/44C22C 38/02C22C 38/004
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Abstract
An austenitic stainless steel hot-rolled steel material can be provided which has sea-water resistance and strength superior to conventional steel. Low-temperature toughness can be maintained, which is preferable in a structural member of speedy craft. The steel material can include an austenitic stainless steel hot-rolled steel material which excels in the properties of corrosion resistance, proof stress, and low-temperature toughness. In such austenitic stainless steel hot-rolling steel material, e.g., PI[=Cr+3.3(Mo+0.5W)+16N] ranges from 35 to 40, δ cal [=2.9 (Cr+0.3Si+Mo+0.5W)−2.6 (Ni+0.3Mn+0.25Cu+35C+20N)−18] ranges from −6 to +2, and a 0.2% proof stress at room temperature is not less than 550 MPa, Charpy impact value measured using a V-notch test piece at −40° C. is not less than 100 J/cm2, and the pitting potential measured in a deaerated aqueous solution of 10% NaCl at 50° C. (Vc′100) is not less than 500 mV (as it relates to saturated Ag/AgCl).
Claims
exact text as granted — not AI-modified1 - 10 . (canceled)
11 . An austenitic stainless hot-rolled steel material having a superior corrosion resistance, a proof stress, and a low-temperature toughness, comprising,
C: about 0.001 to 0.03 mass %, Si: about 0.1 to 1.5 mass %, Mn: about 0.1 to 3.0 mass %, P: about 0.005 to 0.05 mass %, S: about 0.0001 to 0.003 mass %, Ni: about 15.0 to 21.0 mass %; Cr: about 22.0 to 28.0 mass %, Mo: about 1.5 to 3.5 mass %, N: about 0.15 to 0.35 mass %, and O: about 0.0005 to 0.007 mass %, wherein: a Pi value expressed by the following formula ranges from about 35 to 40: PI=Cr+3.3(Mo+0.5W)+16N, and a δ cal value expressed by the following formula ranges from about −6 to +2: δcal=2.9(Cr+0.3Si+Mo+0.5W)−2.6(Ni+0.3Mn+0.25Cu+35C+20N)−18 a remnant of the steel material comprising Fe and inevitable impurities, a content of intermetallic compounds contained in the steel material is at most about 0.5 mass %, about 0.2% proof stress at a room temperature is at least about 550MPa, a Charpy impact value measured using a V-notch test piece at about −40° C. is at least about 100 J/cm 2 , and a pitting potential measured in a deaerated aqueous solution of about 10% NaCl at about 50° C. (Vc′100) is at least about 500 mV as compared to a saturated solution of Ag/AgCl.
12 . The steel material according to claim 11 , further comprising at least one of:
W: about 0.3 to 3.0 mass %, or Al: about 0.005 to 0.1 mass %.
13 . The steel material according to claim 11 , further comprising at least one of:
W: about 0.3 to 3.0 mass %, Al: about 0.005 to 0.1 mass %, Cu: about 0.3 to 2.0 mass %, or Sn: at most about 0.1 mass %.
14 . The steel material according to claim 11 , further comprising at least one of:
W: about 0.3 to 3.0 mass %, Al: about 0.005 to 0.1 mass %, Cu: about 0.3 to 2.0 mass %, Sn: about at most about 0.1 mass %, Ca: about 0.0005 to 0.0050 mass %, Mg: about 0.0005 to 0.0050 mass %, or REM: about 0.005 to 0.10 mass %.
15 . The steel material according to claim 11 , further comprising at least one of:
W: about 0.3 to 3.0 mass %, Al: about 0.005 to 0.1 mass %, Cu: about 0.3 to 2.0 mass %, Sn: about at most about 0.1 mass %, Ca: about 0.0005 to 0.0050 mass %, Mg: about 0.0005 to 0.0050 mass %, REM: about 0.005 to 0.10 mass %, or B: about 0.0003 to 0.0060 mass %.
16 . The steel material according to claim 11 , further comprising at least one of:
W: about 0.3 to 3.0 mass %, Al: about 0.005 to 0.1 mass %, Cu: about 0.3 to 2.0 mass %, Sn: at most about 0.1 mass %, Ca: about 0.0005 to 0.0050 mass %, Mg: about 0.0005 to 0.0050 mass %, REM: about 0.005 to 0.10 mass %, B: about 0.0003 to 0.0060 mass %, Ti: about 0.003 to 0.03 mass %, Nb: about 0.02 to 0.20 mass %, Zr: about 0.003 to 0.03 mass %, V: about 0.05 to 0.5 mass %, or Ta: about 0.01 to 0.1 mass %.
17 . A process for producing an austenitic stainless hot-rolled steel material having a superior corrosion resistance, a proof stress, and a low-temperature toughness, wherein a content of intermetallic compounds contained in the steel material is at most about 0.5 mass %, about 0.2% proof stress at a room temperature is at least about 550 MPa, a Charpy impact value measured using a V-notch test piece at about −40° C. is at least about 100 J/cm 2 , and a pitting potential measured in a deaerated aqueous solution of about 10% NaCl at about 50° C. (Vc′100) is at least about 500 mV as compared to a saturated solution of Ag/AgCl, the process comprising:
performing, at a temperature of about 1200 to 1300° C. for at least about one hour, a homogenizing-heat treatment on a particular material which is at least one of a cast steel or a semi-finished product of the steel material which comprises:
C: about 0.001 to 0.03 mass %,
Si: about 0.1 to 1.5 mass %,
Mn: about 0.1 to 3.0 mass %,
P: about 0.005 to 0.05 mass %,
S: about 0.0001 to 0.003 mass %,
Ni: about 15.0 to 21.0 mass %;
Cr: about 22.0 to 28.0 mass %,
Mo: about 1.5 to 3.5 mass %,
N: about 0.15 to 0.35 mass %, and
O: about 0.0005 to 0.007 mass %,
wherein a PI value expressed by the following formula ranges from about 35 to 40: PI=Cr+3.3(Mo+0.5W)+16N, and
a δ cal value expressed by the following formula ranges from about −6 to +2:
δcal=2.9(Cr+0.3Si+Mo+0.5W)−2.6(Ni+0.3Mn+0.25Cu+35C+20N)−18
a remnant of the steel material comprising Fe and inevitable impurities,
reheating the particular treated material at a temperature of about 1100 to 1300° C.; while rolling the particular reheated material, maintaining a temperature of at least about 850° C., and by a first draft of at least about 50% at a temperature of at least about 1050° C. and a second draft of at least about 10% at a temperature of about 1050 to 850° C.; and cooling the rolled particular material at an average cooling rate of about 800 to 500° C. after the rolling procedure is performed for at least about 150° C./min, without a solution treatment.
18 . An austenitic stainless hot-rolled steel material having a superior corrosion resistance and a low-temperature toughness, comprising,
C: at most about 0.03 mass %, Si: about 0.1 to 1.5 mass %, Mn: about 0.1 to 3.0 mass %, P: at most about 0.05 mass %, S: at most about 0.003 mass %, Ni: about 15.0 to 21.0 mass %, Cr: about 22.0 to 28.0 mass %, Mo: about 1.5 to 3.5 mass %, N: about 0.15 to 0.35 mass %, Al: about 0.005 to 0.1 mass %, and O: at most about 0.007 mass %, wherein a PI value expressed by the following formula ranges from about 35 to 40: PI=Cr+3.3(Mo+0.5W)+16N, and a δ cal value expressed by the following formula ranges from about −6 to +4: δcal=2.9(Cr+0.3Si+Mo+0.5W)−2.6(Ni+0.3Mn+0.25Cu+35C+20N)−18 a remnant of the steel material comprising of Fe and substantially inevitable impurities, and a content of intermetallic compounds contained in the steel material is at most about 0.5 mass %, and a value by each element represents the content of the element expressed in terms of mass %.
19 . The steel material according to claim 18 , further comprising at least one of:
Cu: about 0.1 to 2.0 mass %, Ti: about 0.003 to 0.03 mass %, Nb: about 0.02 to 0.20 mass %, V: about 0.05 to 0.5 mass %, W: about 0.3 to 3.0 mass %, B: about 0.0003 to 0.0060 mass %, Ca: about 0.0005 to 0.0050 mass %, Mg: about 0.0005 to 0.0050 mass %, or REM: about 0.005 to 0.10.
20 . A process for producing an austenitic stainless hot-rolled steel material having a superior corrosion resistance and a low-temperature toughness, wherein a content of intermetallic compounds contained in the steel material is at most about 0.5 mass %, the process comprising:
performing, at a temperature of about 1200 to 1300° C. for at least about one hour, a homogenizing-heat treatment on a particular material which is at least one of a cast steel or a semi-finished product of the steel material which comprises:
C: at most about 0.03 mass %,
Si: about 0.1 to 1.5 mass %,
Mn: about 0.1 to 3.0 mass %,
P: at most about 0.05 mass %,
S: at most about 0.003 mass %,
Ni: about 15.0 to 21.0 mass %,
Cr: about 22.0 to 28.0 mass %,
Mo: about 1.5 to 3.5 mass %,
N: about 0.15 to 0.35 mass %,
Al: about 0.005 to 0.1 mass %, and
O: at most about 0.007 mass %,
wherein a PI value expressed by the following formula ranges from about 35 to 40: PI=Cr+3.3(Mo+0.5W)+16N, and a δ cal value expressed by the following formula ranges from about −6 to +4: δcal=2.9(Cr+0.3Si+Mo+0.5W)−2.6(Ni+0.3Mn+0.25Cu+35C+20N)−18 a remnant of the steel material comprising of Fe and substantially inevitable impurities, a value by each element represents the content of the element expressed in terms of mass %, and the heat treatment is performed so as to reduce the content of the intermetallic compound in the steel material.
21 . A process for producing an austenitic stainless hot-rolled steel material having a superior corrosion resistance, a proof stress, and a low-temperature toughness, wherein a content of intermetallic compounds contained in the steel material is at most about 0.5 mass %, about 0.2% proof stress at a room temperature is at least about 550 MPa, a Charpy impact value measured using a V-notch test piece at about −40° C. is at least about 100 J/cm 2 , and a pitting potential measured in a deaerated aqueous solution of about 10% NaCl at about 50° C. (Vc′100) is at least about 500 mV as compared to a saturated solution of Ag/AgCl, the process comprising:
performing, at a temperature of about 1200 to 1300° C. for at least about one hour, a homogenizing-heat treatment on a particular material which is at least one of a cast steel or a semi-finished product of the steel material which comprises:
C: about 0.001 to 0.03 mass %,
Si: about 0.1 to 1.5 mass %,
Mn: about 0.1 to 3.0 mass %,
P: about 0.005 to 0.05 mass %,
S: about 0.0001 to 0.003 mass %,
Ni: about 15.0 to 21.0 mass %;
Cr: about 22.0 to 28.0 mass %,
Mo: about 1.5 to 3.5 mass %,
N: about 0.15 to 0.35 mass %,
O: about 0.0005 to 0.007 mass %, and
at least one of:
W: about 0.3 to 3.0 mass %, or
Al: about 0.005 to 0.1 mass %.
wherein a PI value expressed by the following formula ranges from about 35 to 40: PI=Cr+3.3(Mo+0.5W)+16N,
a δ cal value expressed by the following formula ranges from about −6 to +2:
δcal=2.9(Cr+0.3Si+Mo+0.5W)−2.6(Ni+0.3Mn+0.25Cu+35C+20N)−18, and
a remnant of the steel material comprising Fe and inevitable impurities;
reheating the particular treated material at a temperature of about 1100 to 1300° C.; while rolling the particular reheated material at a temperature of at least about 850° C., and by a first draft of at least about 1050% at a temperature of at least about 1 050° C. and a second draft of at least about 10% at a temperature of about 1050 to 850° C.; and cooling the rolled particular material at an average cooling rate of about 800 to 500° C. after the rolling procedure is performed for at least about 150° C./min, without a solution treatment.
22 . A process for producing an austenitic stainless hot-rolled steel material having a superior corrosion resistance, a proof stress, and a low-temperature toughness, wherein a content of intermetallic compounds contained in the steel material is at most about 0.5 mass %, about 0.2% proof stress at a room temperature is at least about 550 MPa, a Charpy impact value measured using a V-notch test piece at about −40° C. is at least about 100 J/cm 2 , and a pitting potential measured in a deaerated aqueous solution of about 10% NaCl at about 50° C. (Vc′100) is at least about 500 mV as compared to a saturated solution of Ag/AgCl, the process comprising:
performing, at a temperature of about 1200 to 1300° C. for at least about one hour, a homogenizing-heat treatment on a particular material which is at least one of a cast steel or a semi-finished product of the steel material which comprises:
C: about 0.001 to 0.03 mass %,
Si: about 0.1 to 1.5 mass %,
Mn: about 0.1 to 3.0 mass %,
P: about 0.005 to 0.05 mass %,
S: about 0.0001 to 0.003 mass %,
Ni: about 15.0 to 21.0 mass %;
Cr: about 22.0 to 28.0 mass %,
Mo: about 1.5 to 3.5 mass %,
N: about 0.15 to 0.35 mass %,
O: about 0.0005 to 0.007 mass %, and
at least one of:
W: about 0.3 to 3.0 mass %,
Al: about 0.005 to 0.1 mass %,
Cu: about 0.3 to 2.0 mass %, or
Sn: at most about 0.1 mass %,
wherein a PI value expressed by the following formula ranges from about 35 to 40: PI=Cr+3.3(Mo+0.5W)+16N,
a δ cal value expressed by the following formula ranges from about −6 to +2:
δcal=2.9(Cr+0.3Si+Mo+0.5W)−2.6(Ni+0.3Mn+0.25Cu+35C+20N)−18, and
a remnant of the steel material comprising Fe and inevitable impurities,
reheating the particular treated material at a temperature of about 1100 to 1300° C.;
while rolling the particular reheated material maintaining a temperature of at least about 850° C., and by a first draft of at least about 50% at a temperature of at least about 1050° C. and a second draft of at least about 10% at a temperature of about 1050 to 850° C.; and cooling the rolled particular material at an average cooling rate of about 800 to 500° C. after the rolling procedure is performed for at least about 150° C./min, without a solution treatment.
23 . A process for producing an austenitic stainless hot-rolled steel material having a superior corrosion resistance, a proof stress, and a low-temperature toughness, wherein a content of intermetallic compounds contained in the steel material is at most about 0.5 mass %, about 0.2% proof stress at a room temperature is at least about 550 MPa, a Charpy impact value measured using a V-notch test piece at about −40° C. is at least about 100 J/cm 2 , and a pitting potential measured in a deaerated aqueous solution of about 10% NaCl at about 50° C. (Vc′100) is at least about 500 mV as compared to a saturated solution of Ag/AgCl, the process comprising:
performing, at a temperature of about 1200 to 1300° C. for at least about one hour, a homogenizing-heat treatment on a particular material which is at least one of a cast steel or a semi-finished product of the steel material which comprises:
C: about 0.001 to 0.03 mass %,
Si: about 0.1 to 1.5 mass %,
Mn: about 0.1 to 3.0 mass %,
P: about 0.005 to 0.05 mass %,
S: about 0.0001 to 0.003 mass %,
Ni: about 15.0 to 21.0 mass %;
Cr: about 22.0 to 28.0 mass %,
Mo: about 1.5 to 3.5 mass %,
N: about 0.15 to 0.35 mass %,
O: about 0.0005 to 0.007 mass %, and at least one of:
W: about 0.3 to 3.0 mass %,
Al: about 0.005 to 0.1 mass %,
Cu: about 0.3 to 2.0 mass %,
Sn: about at most about 0.1 mass %,
Ca: about 0.0005 to 0.0050 mass %,
Mg: about 0.0005 to 0.0050 mass %, or
REM: about 0.005 to 0.10 mass %,
wherein a PI value expressed by the following formula ranges from about 35 to 40: PI=Cr+3.3(Mo+0.5W)+16N,
a δ cal value expressed by the following formula ranges from about −6 to +2:
δcal=2.9(Cr+0.3Si+Mo+0.5W)−2.6 (Ni+0.3Mn+0.25Cu+35C+20N)−18, and
a remnant of the steel material comprising Fe and inevitable impurities, reheating the particular treated material at a temperature of about 1100 to 1300° C.;
while rolling the particular reheated material maintaining a temperature of at least about 850° C., and by a first draft of at least about 50% at a temperature of at least about 1050° C. and a second draft of at least about 10% at a temperature of about 1050 to 850° C.; and cooling the rolled particular material at an average cooling rate of about 800 to 500° C. after the rolling procedure is performed for at least about 150° C./min, without a solution treatment.
24 . A process for producing an austenitic stainless hot-rolled steel material having a superior corrosion resistance, a proof stress, and a low-temperature toughness, wherein a content of intermetallic compounds contained in the steel material is at most about 0.5 mass %, about 0.2% proof stress at a room temperature is at least about 550 MPa, a Charpy impact value measured using a V-notch test piece at about −40° C. is at least about 100 J/cm 2 , and a pitting potential measured in a deaerated aqueous solution of about 10% NaCl at about 50° C. (Vc′100) is at least about 500 mV as compared to a saturated solution of Ag/AgCl, the process comprising:
performing, at a temperature of about 1200 to 1300° C. for at least about one hour, a homogenizing-heat treatment on a particular material which is at least one of a cast steel or a semi-finished product of the steel material which comprises:
C: about 0.001 to 0.03 mass %,
Si: about 0.1 to 1.5 mass %,
Mn: about 0.1 to 3.0 mass %,
P: about 0.005 to 0.05 mass %,
S: about 0.0001 to 0.003 mass %,
Ni: about 15.0 to 21.0 mass %;
Cr: about 22.0 to 28.0 mass %,
Mo: about 1.5 to 3.5 mass %,
N: about 0.15 to 0.35 mass %, p 2 O: about 0.0005 to 0.007 mass %, and at least one of:
W: about 0.3 to 3.0 mass %,
Al: about 0.005 to 0.1 mass %,
Cu: about 0.3 to 2.0 mass %,
Sn: at most about 0.1 mass %,
Ca: about 0.0005 to 0.0050 mass %,
Mg: about 0.0005 to 0.0050 mass %,
REM: about 0.005 to 0.10 mass %, or
B: about 0.0003 to 0.0060 mass %,
wherein a PI value expressed by the following formula ranges from about 35 to 40: PI=Cr+3.3(Mo+0.5W)+16N,
a δ cal value expressed by the following formula ranges from about −6 to +2:
δcal=2.9(Cr+0.3Si+Mo+0.5W)−2.6(Ni+0.3Mn+0.25Cu+35C+20N)−18, and
a remnant of the steel material comprising Fe and inevitable impurities,
reheating the particular treated material at a temperature of about 1100 to 1300° C.; while rolling the particular reheated material maintaining a temperature of at least about 850° C., and by a first draft of at least about 50% at a temperature of at least about 1050° C. and a second draft of at least about 10% at a temperature of about 1050 to 850° C.; and cooling the rolled particular material at an average cooling rate of about 800 to 500° C. after the rolling procedure is performed for at least about 150° C./min, without a solution treatment.
25 . A process for producing an austenitic stainless hot-rolled steel material having a superior corrosion resistance, a proof stress, and a low-temperature toughness, wherein a content of intermetallic compounds contained in the steel material is at most about 0.5 mass %, about 0.2% proof stress at a room temperature is at least about 550 MPa, a Charpy impact value measured using a V-notch test piece at about −40° C. is at least about 100 J/cm 2 , and a pitting potential measured in a deaerated aqueous solution of about 10% NaCl at about 50° C. (Vc′100) is at least about 500 mV as compared to a saturated solution of Ag/AgCl, the process comprising:
performing, at a temperature of about 1200 to 1300° C. for at least about one hour, a homogenizing-heat treatment on a particular material which is at least one of a cast steel or a semi-finished product of the steel material which comprises:
C: about 0.001 to 0.03 mass %,
Si: about 0.1 to 1.5 mass %,
Mn: about 0.1 to 3.0 mass %,
P: about 0.005 to 0.05 mass %,
S: about 0.0001 to 0.003 mass %,
Ni: about 15.0 to 21.0 mass %;
Cr: about 22.0 to 28.0 mass %,
Mo: about 1.5 to 3.5 mass %,
N: about 0.15 to 0.35 mass %,
O: about 0.0005 to 0.007 mass %, and
at least one of:
W: about 0.3 to 3.0 mass %,
Al: about 0.005 to 0.1 mass %,
Cu: about 0.3 to 2.0 mass %,
Sn: at most about 0.1 mass %,
Ca: about 0.0005 to 0.0050 mass %,
Mg: about 0.0005 to 0.0050 mass %,
REM: about 0.005 to 0.10 mass %,
B: about 0.0003 to 0.0060 mass %,
Ti: about 0.003 to 0.03 mass %,
Nb: about 0.02 to 0.20 mass %,
Zr: about 0.003 to 0.03 mass %,
V: about 0.05 to 0.5 mass %, or
Ta: about 0.01 to 0.1 mass %,
wherein a PI value expressed by the following formula ranges from about 35 to 40: PI=Cr+3.3(Mo+0.5W)+16N,
a δ cal value expressed by the following formula ranges from about −6 to +2:
δcal=2.9(Cr+0.3Si+Mo+0.5W)−2.6(Ni+0.3Mn+0.25Cu+35C+20N)−18, and
a remnant of the steel material comprising Fe and inevitable impurities,
reheating the particular treated material at a temperature of about 1100 to 1300° C.; while rolling the particular reheated material maintaining a temperature of at least about 850° C., and by a first draft of at least about 50% at a temperature of at least about 1050° C. and a second draft of at least about 10% at a temperature of about 1050 to 850° C.; and cooling the rolled particular material at an average cooling rate of about 800 to 500° C. after the rolling procedure is performed for at least about 150° C./min, without a solution treatment.
26 . A process for producing an austenitic stainless hot-rolled steel material having a superior corrosion resistance and a low-temperature toughness, wherein a content of intermetallic compounds contained in the steel material is at most about 0.5 mass %, the process comprising:
performing, at a temperature of about 1200 to 1300° C. for at least about one hour, a homogenizing-heat treatment on a particular material which is at least one of a cast steel or a semi-finished product of the steel material which comprises:
C: at most about 0.03 mass %,
Si: about 0.1 to 1.5 mass %,
Mn: about 0.1 to 3.0 mass %,
P: at most about 0.05 mass %,
S: at most about 0.003 mass %,
Ni: about 15.0 to 21.0 mass %,
Cr: about 22.0 to 28.0 mass %,
Mo: about 1.5 to 3.5 mass %,
N: about 0.15 to 0.35 mass %,
Al: about 0.005 to 0.1 mass %, and
O: at most about 0.007 mass %, and
at least one of:
Cu: about 0.1 to 2.0 mass %,
Ti: about 0.003 to 0.03 mass %,
Nb: about 0.02 to 0.20 mass %,
V: about 0.05 to 0.5 mass %,
W: about 0.3 to 3.0 mass %,
B: about 0.0003 to 0.0060 mass %,
Ca: about 0.0005 to 0.0050 mass %,
Mg: about 0.0005 to 0.0050 mass %, or
REM: about 0.005 to 0.10,
wherein
a PI value expressed by the following formula ranges from about 35 to 40:
PI=Cr+3.3(Mo+0.5W)+16N, and
a δ cal value expressed by the following formula ranges from about 6 to +4:
δcal=2.9(Cr+0.3Si+Mo+0.5W)−2.6(Ni +0.3Mn+0.25Cu+35C+20N)−18
a remnant of the steel material comprising of Fe and substantially inevitable impurities,
a value by each element represents the content of the element expressed in terms of mass %, and
the heat treatment is performed so as to reduce the content of the intermetallic compound in the steel material.Join the waitlist — get patent alerts
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