CA1066595A - Method of quenching and tempering large-diameter thin-wall steel pipe and apparatus therefor - Google Patents
Method of quenching and tempering large-diameter thin-wall steel pipe and apparatus thereforInfo
- Publication number
- CA1066595A CA1066595A CA243,800A CA243800A CA1066595A CA 1066595 A CA1066595 A CA 1066595A CA 243800 A CA243800 A CA 243800A CA 1066595 A CA1066595 A CA 1066595A
- Authority
- CA
- Canada
- Prior art keywords
- steel pipe
- quenching
- tempering
- diameter thin
- restraining
- 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
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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
- C21D8/10—Modifying the physical properties by deformation combined with, or followed by, heat treatment during manufacturing of tubular bodies
-
- 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
- C21D9/08—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for tubular bodies or pipes
-
- 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
- C21D9/08—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for tubular bodies or pipes
- C21D9/085—Cooling or quenching
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Manufacturing & Machinery (AREA)
- Heat Treatment Of Articles (AREA)
- General Induction Heating (AREA)
Abstract
Abstract of the Disclosure A method and apparatus for quenching and tempering a large-diameter thin-wall steel pipe without deforming the steel pipe, characterized in that when quenching the steel pipe which has been heated to a quenching temperature to a room temperature, the steel pipe is cooled while restraining or constraining the steel pipe in a desired shape and correcting the steel pipe at a temperature between 400 and 600°C. Further, when tempering the steel pipe, if it is necessary, immediately after the steel pipe has been heated up to a tempering temperature the steel pipe may be restrained and corrected to an exact round shape to thereby produce a quenched and tempered large-diameter thin-wall steel pipe having a further improved roundness.
Description
:10~i6S~
,: :
Background of the Invention The present invention relates to a method and appara-tus or quench-`~ in~ and tempering a large-diameter thin-wall steel pipe which is capable of positively preventing any deformation of the steel pipe which may - occur dllring the heat trea-tment thereof and correcting the s-teel pipe.
- Large-diameter -thin-wall steel pipes, particularly those llaving -~ inner llic~meters in the range of 15 to 60 inches and wall thicknesses - in the range of 6 to 38 mm have heretofore been manufactured by for~ing . . .
the ordinary steel plates by the well known U.O.E. method, I'Oll bending method or spiral method and then welding the open tubes into pipes.
These pipes are generally used for conveying gases, oils or tlle like ~- allll tlle pipes are required to posses such properties as high streJIgth :-. .
; an(l eYcellent toughness at low temperatures. Consequently, it has .~ ~
.; -- 1 --:... , : .. . . . . . .
659~ ~
u~ prl-l( tice in thc l~ast to a(l(l alloyin6 elemerltY including niohi~m, ctc., to tllc stecl platc l`ol pipe for ensurillg an improve~ strengtll and nt th( ~ e time usc tlle ~olltlolle(l rolling method in the manufacture Or tlle ~eel plate for ensllring ml improved tvuehne~s. Ilowever, there arc limits to the imlro~ellle~lt oE these propertie~. Al-ternntely~ a metho(l may be con~idered in whictl a quenched an-l tempered s-teel plate i~ use(l ns -the raw material for pipe and the steel plate is Eormed an(l wel(le-l in-to a pipe. This method is al90 disadvantageolls in m~ny re~pects, namely, the increased streng-th of the steel plate require3 a greater force for forming -the steel plate thus making it impossible to use the conventional equipment and the required new equipment becomes considerably bulky as compared Witll the conventionnl equipment. In nllditioll, wllile these metllo(h~ hnve the effect of consi(lernbly improving ; the propertie~ of the bcnse metnl for s-teel pipe, there is -the di~advan-tage of ~m~atisfactory properties in the weld zone obtained.
- Under these circums-tances, it is considered that the best method of ensuring the desired improved s-trength and toughness in both the base metal an(l the weld zone is one in which the steel plate that has been formed by the above-mentioned U.O.E. method or the like i~ welded into a steel pipe and the welded steel pipe i9 then subjected to quenching and tempering treatments. In other words, this method requires the addition of no expensive alloying elements or alternately the addition of these alloying elements in small amounts can improve the meohanical proper-ties of the welded steel pipe and moreover there is no possibility of reducing ~the rolling efficiency by performing the controlled rolling.
Tlowever, this proposed method is not perfect and it i8 also disadvantageous in that af-ter the quenching operation has occurred, due to the thermal s~less caused by the rapid cooling of the quenching and the stress onused by the transformation, the welded steel pipe is deformed in the dic~metrical direction thus deteriorating its round shape and the welded
,: :
Background of the Invention The present invention relates to a method and appara-tus or quench-`~ in~ and tempering a large-diameter thin-wall steel pipe which is capable of positively preventing any deformation of the steel pipe which may - occur dllring the heat trea-tment thereof and correcting the s-teel pipe.
- Large-diameter -thin-wall steel pipes, particularly those llaving -~ inner llic~meters in the range of 15 to 60 inches and wall thicknesses - in the range of 6 to 38 mm have heretofore been manufactured by for~ing . . .
the ordinary steel plates by the well known U.O.E. method, I'Oll bending method or spiral method and then welding the open tubes into pipes.
These pipes are generally used for conveying gases, oils or tlle like ~- allll tlle pipes are required to posses such properties as high streJIgth :-. .
; an(l eYcellent toughness at low temperatures. Consequently, it has .~ ~
.; -- 1 --:... , : .. . . . . . .
659~ ~
u~ prl-l( tice in thc l~ast to a(l(l alloyin6 elemerltY including niohi~m, ctc., to tllc stecl platc l`ol pipe for ensurillg an improve~ strengtll and nt th( ~ e time usc tlle ~olltlolle(l rolling method in the manufacture Or tlle ~eel plate for ensllring ml improved tvuehne~s. Ilowever, there arc limits to the imlro~ellle~lt oE these propertie~. Al-ternntely~ a metho(l may be con~idered in whictl a quenched an-l tempered s-teel plate i~ use(l ns -the raw material for pipe and the steel plate is Eormed an(l wel(le-l in-to a pipe. This method is al90 disadvantageolls in m~ny re~pects, namely, the increased streng-th of the steel plate require3 a greater force for forming -the steel plate thus making it impossible to use the conventional equipment and the required new equipment becomes considerably bulky as compared Witll the conventionnl equipment. In nllditioll, wllile these metllo(h~ hnve the effect of consi(lernbly improving ; the propertie~ of the bcnse metnl for s-teel pipe, there is -the di~advan-tage of ~m~atisfactory properties in the weld zone obtained.
- Under these circums-tances, it is considered that the best method of ensuring the desired improved s-trength and toughness in both the base metal an(l the weld zone is one in which the steel plate that has been formed by the above-mentioned U.O.E. method or the like i~ welded into a steel pipe and the welded steel pipe i9 then subjected to quenching and tempering treatments. In other words, this method requires the addition of no expensive alloying elements or alternately the addition of these alloying elements in small amounts can improve the meohanical proper-ties of the welded steel pipe and moreover there is no possibility of reducing ~the rolling efficiency by performing the controlled rolling.
Tlowever, this proposed method is not perfect and it i8 also disadvantageous in that af-ter the quenching operation has occurred, due to the thermal s~less caused by the rapid cooling of the quenching and the stress onused by the transformation, the welded steel pipe is deformed in the dic~metrical direction thus deteriorating its round shape and the welded
- 2-:- .. - . . ,.,~. -". . ,,, ~,, :: . ~ :
:. . .. .
sgs ~teel ~ipe i~ ~lso (leforme~ the longitudinal directi~n. In thi~
cnse, since the welded s-teel pipe i9 large in diameter ~n~ thin in wall thickness -the degree of defo~rlation i9 ~urther increa~ed and moreover the vnrious stresses cau~ed during the ~uenchin~ operation are relea~ed during the tempering oper~tion thus giving risè to a consider~ble amount of deformation, though nut so great ag in t~e case of the quenching.
Ilowe~er~ practically no effectiYe method~ have heretnfore been developed for preventing the occurrence of the above-mentioned de-forma-tions due to heat treatments and only some illustrative methods have been disclosed in the Japanese Laid-Open Patent Application Publica-tion No.48-36015.
Summary of the Invention With a view to overcoming the foregoing problem~ it is an object of the present invention to provide a method and apparatus for~quenching and temperiDg a large-diameter thin-wall steel pipe wherein the steel pipe is restrained during the quenching operation to prevent deformation of the steel pipe and moreover, if necessary, immediately after the ~teel pipe has been heated to a tempering temperature -the steel pipe is restrained to straighten or correct the steel pipe to obtaln an exact rolmdnes~.
It is a further object of the present invention to provide a method and apparatus of quenching and tempering a large-diameter thin-wall steel pipe capable of producing a large-diameter this-wall steel pipe having an improved strength and an excellent low temperature toughness without requiring the use of an expensive alloy steel.
Brief Description of the Drawing Fig. 1 is a schematic diagram showing the layout of a quenching ,, . , ~ . , -, ;59S
nn(l ~elllpelinK line nccomlil~g to nn embodimen-t of the invention.
Fi~. 2 i8 a graph sh0wine the relAtionship between the out~of roun(llle~s and the lengthwi~e distnnce of n steel pipe A which were sllbjected to only the quenching proces~ nccordin~ to the invention~
a tnbe B which has been wclded b~t not yet he~t tr0ated (h~rein~ter calle(l ~c~lde -hlbe~) and steel pipes Cl, C2 and C3 produced by the conven tional ne-tho(ls .
Fig. 3(a) is a ~ront view of restraining straightener roller unit.
Fig. 3(b) is a longitudinal side sectional view of the straighten-ing roller~ shown in Fig. 3(a~, and shows the relative position of the roller uni-t with the cooling nozzle meAns 4-1 and 4-2.
Fig. 4 i9 a graph similar to the graph of Fig. 2, showing the out-of-rollndnes~ of a steel pipe A' which was subjected to the quenching and te~pering process according to the invention, the ~teel pipe A
which ~as subjected only to the quenching process according to the invention, the crude tllbe B and a steel pipe C4 which was produced by the conventionAl method.
Description of the Preferred Embodiment The present invention will now be described in greater detail with reference to the illustrated embodiment. Referring first to Fig. 1 showing an embodiment of a quenching and tempering line of steel~pipe according to the invention, a large-diameter thin-wall steel pipe 9 which was conveyed and passed roll gangs 2-1 and 2-2 in the steel pipe traveIing directlon ~hown by an arrow in the Fi~lre is he~ted~
nf-ter pns~ing throllg~l ~inch roll~ 3-1, up to a quenching tempera-ture by a l~eating coil 5 and then either the outer surfnce or inner ~urface or both of the steel pipe 9 are rapidly cooled by cooling nozzles 4-1 to a temperature between 400 and 600 C. When the steel pipe 9 has been cooled to the desired temperature, the steel pipe 9 is fed - :~:: - ; - - , :
~0~
thro~lgll a restrnining straigh-ten~er roller unit 6 for obtaining an exact rolm(lness an(l thcn it is similarly cooled by cooling nozzles ~-2 to a room temperatule thus completing the quenching process.
In -the case o~ this embo~ ellt, when tlle steel pipe 9 has been d~llver-ed over and completely pQssed through pinch rolls 3-2~ the steel pipe 9 is conveyed in the reverse dir~ection and introduced through the pinch rolls 3-2 into tlle heating coil 5 where it i9 heated to a tempering temperature between 500 and 700 C ~nd then the steel pipe 9 i9 restrained and corrected into the desired shape by a restraining s-traightener roller unit 7 from ei-ther of the outer surfaoe or inner surface or both of the steel pipe 9. After passing through the pincll rolls 3-1 again, the steel pipe 9 i8 air cooled ~or tempering purposes thus completing the tempering process. Of cour~e, it i~
possible to accomplish the desired tempering by means of a separate tempering line iDstead of conveying the steel pipe in the reverse direction. In the Figure, numeral 1 de~ignates a pipe end stop, 8 a mandrel over which is introduced an inner surface cooling water or air, 2-~ ~nd 2-4 roll gangs. As will be seen from Figs. 3(a) and
:. . .. .
sgs ~teel ~ipe i~ ~lso (leforme~ the longitudinal directi~n. In thi~
cnse, since the welded s-teel pipe i9 large in diameter ~n~ thin in wall thickness -the degree of defo~rlation i9 ~urther increa~ed and moreover the vnrious stresses cau~ed during the ~uenchin~ operation are relea~ed during the tempering oper~tion thus giving risè to a consider~ble amount of deformation, though nut so great ag in t~e case of the quenching.
Ilowe~er~ practically no effectiYe method~ have heretnfore been developed for preventing the occurrence of the above-mentioned de-forma-tions due to heat treatments and only some illustrative methods have been disclosed in the Japanese Laid-Open Patent Application Publica-tion No.48-36015.
Summary of the Invention With a view to overcoming the foregoing problem~ it is an object of the present invention to provide a method and apparatus for~quenching and temperiDg a large-diameter thin-wall steel pipe wherein the steel pipe is restrained during the quenching operation to prevent deformation of the steel pipe and moreover, if necessary, immediately after the ~teel pipe has been heated to a tempering temperature -the steel pipe is restrained to straighten or correct the steel pipe to obtaln an exact rolmdnes~.
It is a further object of the present invention to provide a method and apparatus of quenching and tempering a large-diameter thin-wall steel pipe capable of producing a large-diameter this-wall steel pipe having an improved strength and an excellent low temperature toughness without requiring the use of an expensive alloy steel.
Brief Description of the Drawing Fig. 1 is a schematic diagram showing the layout of a quenching ,, . , ~ . , -, ;59S
nn(l ~elllpelinK line nccomlil~g to nn embodimen-t of the invention.
Fi~. 2 i8 a graph sh0wine the relAtionship between the out~of roun(llle~s and the lengthwi~e distnnce of n steel pipe A which were sllbjected to only the quenching proces~ nccordin~ to the invention~
a tnbe B which has been wclded b~t not yet he~t tr0ated (h~rein~ter calle(l ~c~lde -hlbe~) and steel pipes Cl, C2 and C3 produced by the conven tional ne-tho(ls .
Fig. 3(a) is a ~ront view of restraining straightener roller unit.
Fig. 3(b) is a longitudinal side sectional view of the straighten-ing roller~ shown in Fig. 3(a~, and shows the relative position of the roller uni-t with the cooling nozzle meAns 4-1 and 4-2.
Fig. 4 i9 a graph similar to the graph of Fig. 2, showing the out-of-rollndnes~ of a steel pipe A' which was subjected to the quenching and te~pering process according to the invention, the ~teel pipe A
which ~as subjected only to the quenching process according to the invention, the crude tllbe B and a steel pipe C4 which was produced by the conventionAl method.
Description of the Preferred Embodiment The present invention will now be described in greater detail with reference to the illustrated embodiment. Referring first to Fig. 1 showing an embodiment of a quenching and tempering line of steel~pipe according to the invention, a large-diameter thin-wall steel pipe 9 which was conveyed and passed roll gangs 2-1 and 2-2 in the steel pipe traveIing directlon ~hown by an arrow in the Fi~lre is he~ted~
nf-ter pns~ing throllg~l ~inch roll~ 3-1, up to a quenching tempera-ture by a l~eating coil 5 and then either the outer surfnce or inner ~urface or both of the steel pipe 9 are rapidly cooled by cooling nozzles 4-1 to a temperature between 400 and 600 C. When the steel pipe 9 has been cooled to the desired temperature, the steel pipe 9 is fed - :~:: - ; - - , :
~0~
thro~lgll a restrnining straigh-ten~er roller unit 6 for obtaining an exact rolm(lness an(l thcn it is similarly cooled by cooling nozzles ~-2 to a room temperatule thus completing the quenching process.
In -the case o~ this embo~ ellt, when tlle steel pipe 9 has been d~llver-ed over and completely pQssed through pinch rolls 3-2~ the steel pipe 9 is conveyed in the reverse dir~ection and introduced through the pinch rolls 3-2 into tlle heating coil 5 where it i9 heated to a tempering temperature between 500 and 700 C ~nd then the steel pipe 9 i9 restrained and corrected into the desired shape by a restraining s-traightener roller unit 7 from ei-ther of the outer surfaoe or inner surface or both of the steel pipe 9. After passing through the pincll rolls 3-1 again, the steel pipe 9 i8 air cooled ~or tempering purposes thus completing the tempering process. Of cour~e, it i~
possible to accomplish the desired tempering by means of a separate tempering line iDstead of conveying the steel pipe in the reverse direction. In the Figure, numeral 1 de~ignates a pipe end stop, 8 a mandrel over which is introduced an inner surface cooling water or air, 2-~ ~nd 2-4 roll gangs. As will be seen from Figs. 3(a) and
3(b), the re~training straightener roli unit 6 designed to ef~ect the rolmdness correction from the outer surface o~ the pipe comprises a plurality of straightening rollers 10 which are pre~sed against the outer surface of the centrally located steel pipe 9 to be corrected and the cooling nozzles 1~1 and 4-2 are respectively arranged at the front and rear sides of the rollers 10 to cool the steel pipe 9 with the front nozzles to a proper restraining and ~traightening temperature which in this exemplary ca~e lies between 400 and 600 C. The re-straining straightener roller unit 7 for correcting the steel pipe into the desired shape immediately after the tempering is similar in construction with the restraining straightener roller unit 6 except tllat the former is not equipped with any cooling nozzles.
10~i659~
Tlle restrained strni~llte~ g or correction by Wle roller Imi-ts anll 7 mny be accomplishell in many dirferent ways. For example~
tlle restrained correction mny be accomplished irom the ilmer surface o n steel pipe or alternately it may be effected from both the inner and outer surfaces of a steel pipe.
In nccordance wnth the present invention, the pr~per temperature range for quenching~ i.e., the tempera~ure range oi l~oo to 600 C
al)proximntely corresponds to the temperature range of steel ~or passing through the martensite or bainite transformation point~.
Consequently, by restraining the steel in this temperature range it is po~ible to minimize the amoun-t of deformation due to the trans-fo~nation. On the other hand, i$ the steel pipe is restrained at temperatures above this temperature range, the transformation takes place below the3e temperatures thu~ causing deformation in the steel, whereas if the steel pipe is restrained at temperatures below the above-mentioned temperature range the transformation deformation must be corrected after the -transformation has taken place thus malcing it diificult to effect the correction due to an increased defo =ation resistance.
Consequently, in the above-mentioned temperature ranRe the trans-fo~nation deformation may be easily corrected with a small force to ensure an approximately exact roundnes~ of the steel pipe and moreover by restraining the steel pipe at temperatures within this temperature range it is possible to minimize the amount of deformation due to thermal stresses. W~lile a steel pipe having a reduced amount of deformation as compared with the conventional products may be produced by accomplishing the required constrained correction at temperatures in the above-mentioned temperature range during the qnenching process without using the correction at the tempering stage 9 and thus the resulting product is fully satisfactory in many appli--;; ' , .. . ... .. .
. : - .- : . - ~
~L0~6S~5 cnti~ , (hle to the fnct thal variouY -types of internal stress are l'I'le~Sed during tlle tempering thlls causing deformation of the steel pi lle, it is preferable to l~ent tlle steel pipe to a tempering tempera-ture oI 500 -to 700 C and then restrain and correct tlle steel pipe to the ~lesired shape. ~lether the cooling o~ a steel pipe during the quenclling process is effec-ted from the outer surface or\inner surface botll tll~ ollter and inner sQrfaces of the steel pipe is dete~ ed in consideration of 8uch factors a~ the pipe wall thickness and so on, while on the other hand whether the re~trained correction during the quenching and tempering processes, respectively, is effected -~rom the ou-ter surface or inner surface or both the outer and inner surfaces ol tlle steel pipe is de-termined in consideration of the amount of deformation. Further, as regards the relationship between the arrange-ment of the restraining straightening rollers and the cooling noz~les during the quenching~ the rollers should preferrably be arranged on the side where the cooling no~zles are arranged, namely, while the temperature of the central portion of the steel pipe remains at a value between ~00 and 600C, the temperature of the pipe surface to W}liCh the cooling water is sprayed becomes lower than that of the cen-tral portion and consequently the restrained correotion can be accomplished~without causing defects on the outer or inner surface ;
of the steel pipe. ~ ~ ~
Referring now to the graph of Fig. 2 showing the results of the tes-ts conducted with the method according to the invention, ~the ou-t-of-ro~mdness of the steel pipe which was subjected to the outer surface cooling~ outer surface restraining and correction and only the quenching process according to the invention was smnll and its deformation was almost negligible as compared with the deformation present in the crude tube. In addition, the shapeability oi the steel pipe produced according to the present invention was far .: - .~ -. . -. .: - ~ .
g5 ~nl>eriol ~ that o~ the pro(lucts pro~ ce~ by the cvnventional me-thodY.
ther~ as will be seen from Fig, 4~ the ~teel pipe whicll was ~ubjected to the (luencl~ g an-l temllerinS procoss aecording to the invention stlowe(l nlmost no defornmtiotl as compared with the crude tube~ while tlle steel pipe which was subjec-ted only to the quenchin~ proces~
nccor(ling to -the invention sllowed a grenter degree of d~formation as col~ lre(l witll the crude tube but the degree o~ defor~Ation w~ till smaller -thfln thnt of the products produced by the conventionnl me-thods~
n~uely, itl the case of a steel pipe having an outer diameter o~ 36 inches the amount of deformation was kept at about 10 mm which wa9 ~airly within -the permissible range.
10~i659~
Tlle restrained strni~llte~ g or correction by Wle roller Imi-ts anll 7 mny be accomplishell in many dirferent ways. For example~
tlle restrained correction mny be accomplished irom the ilmer surface o n steel pipe or alternately it may be effected from both the inner and outer surfaces of a steel pipe.
In nccordance wnth the present invention, the pr~per temperature range for quenching~ i.e., the tempera~ure range oi l~oo to 600 C
al)proximntely corresponds to the temperature range of steel ~or passing through the martensite or bainite transformation point~.
Consequently, by restraining the steel in this temperature range it is po~ible to minimize the amoun-t of deformation due to the trans-fo~nation. On the other hand, i$ the steel pipe is restrained at temperatures above this temperature range, the transformation takes place below the3e temperatures thu~ causing deformation in the steel, whereas if the steel pipe is restrained at temperatures below the above-mentioned temperature range the transformation deformation must be corrected after the -transformation has taken place thus malcing it diificult to effect the correction due to an increased defo =ation resistance.
Consequently, in the above-mentioned temperature ranRe the trans-fo~nation deformation may be easily corrected with a small force to ensure an approximately exact roundnes~ of the steel pipe and moreover by restraining the steel pipe at temperatures within this temperature range it is possible to minimize the amount of deformation due to thermal stresses. W~lile a steel pipe having a reduced amount of deformation as compared with the conventional products may be produced by accomplishing the required constrained correction at temperatures in the above-mentioned temperature range during the qnenching process without using the correction at the tempering stage 9 and thus the resulting product is fully satisfactory in many appli--;; ' , .. . ... .. .
. : - .- : . - ~
~L0~6S~5 cnti~ , (hle to the fnct thal variouY -types of internal stress are l'I'le~Sed during tlle tempering thlls causing deformation of the steel pi lle, it is preferable to l~ent tlle steel pipe to a tempering tempera-ture oI 500 -to 700 C and then restrain and correct tlle steel pipe to the ~lesired shape. ~lether the cooling o~ a steel pipe during the quenclling process is effec-ted from the outer surface or\inner surface botll tll~ ollter and inner sQrfaces of the steel pipe is dete~ ed in consideration of 8uch factors a~ the pipe wall thickness and so on, while on the other hand whether the re~trained correction during the quenching and tempering processes, respectively, is effected -~rom the ou-ter surface or inner surface or both the outer and inner surfaces ol tlle steel pipe is de-termined in consideration of the amount of deformation. Further, as regards the relationship between the arrange-ment of the restraining straightening rollers and the cooling noz~les during the quenching~ the rollers should preferrably be arranged on the side where the cooling no~zles are arranged, namely, while the temperature of the central portion of the steel pipe remains at a value between ~00 and 600C, the temperature of the pipe surface to W}liCh the cooling water is sprayed becomes lower than that of the cen-tral portion and consequently the restrained correotion can be accomplished~without causing defects on the outer or inner surface ;
of the steel pipe. ~ ~ ~
Referring now to the graph of Fig. 2 showing the results of the tes-ts conducted with the method according to the invention, ~the ou-t-of-ro~mdness of the steel pipe which was subjected to the outer surface cooling~ outer surface restraining and correction and only the quenching process according to the invention was smnll and its deformation was almost negligible as compared with the deformation present in the crude tube. In addition, the shapeability oi the steel pipe produced according to the present invention was far .: - .~ -. . -. .: - ~ .
g5 ~nl>eriol ~ that o~ the pro(lucts pro~ ce~ by the cvnventional me-thodY.
ther~ as will be seen from Fig, 4~ the ~teel pipe whicll was ~ubjected to the (luencl~ g an-l temllerinS procoss aecording to the invention stlowe(l nlmost no defornmtiotl as compared with the crude tube~ while tlle steel pipe which was subjec-ted only to the quenchin~ proces~
nccor(ling to -the invention sllowed a grenter degree of d~formation as col~ lre(l witll the crude tube but the degree o~ defor~Ation w~ till smaller -thfln thnt of the products produced by the conventionnl me-thods~
n~uely, itl the case of a steel pipe having an outer diameter o~ 36 inches the amount of deformation was kept at about 10 mm which wa9 ~airly within -the permissible range.
Claims (3)
1. A method of quenching and tempering a large-diameter thin-wall steel pipe wherein in the step of quenching and tempering a large-diameter thin-wall steel pipe, during said quenching said steel pipe is cooled while restraining and correcting said steel pipe to a desired shape at a temperature in the range of 400 to 600°C to thereby reform said heat treated steel pipe into said desired shape.
2. A method of quenching and tempering a large-diameter thin-wall steel pipe wherein in the step of quenching and tempering a large-diameter thin-wall steel pipe, during said quenching said steel pipe is cooled while restraining and correcting said steel pipe to a desired shape at a temperature in the range of 400 to 600 C, and any deformation caused in said steel pipe during said tempering is correct-ed immediately after said tempering of said steel pipe, thereby to reform said steel pipe into said desired shape.
3. In an apparatus for quenching and tempering a large-diameter thin-wall steel pipe, the improvement comprising restraining straightener roller means for restraining and correcting a large-diameter thin-wall steel pipe to a desired shape at a temperature in the range of 400 to 600°C during the process of quenching, said restraining straightener roller means including cooling nozzle means provided at each of the entry and delivery sides thereof.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP968975A JPS5818404B2 (en) | 1975-01-24 | 1975-01-24 | It's important to know what's going on. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1066595A true CA1066595A (en) | 1979-11-20 |
Family
ID=11727172
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA243,800A Expired CA1066595A (en) | 1975-01-24 | 1976-01-19 | Method of quenching and tempering large-diameter thin-wall steel pipe and apparatus therefor |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JPS5818404B2 (en) |
| CA (1) | CA1066595A (en) |
| DE (1) | DE2601625C3 (en) |
| IT (1) | IT1054255B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108517398A (en) * | 2018-06-26 | 2018-09-11 | 安徽马钢设备检修有限公司 | A kind of Large Diameter Pipeline thin-wall tube post weld heat treatment device and its application method |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102008009009B3 (en) * | 2008-02-13 | 2009-01-02 | Esser-Werke Gmbh & Co. Kg | Procedure for heat treatment of a tube body of a feed pipe to transport highly abrasive solids, comprises heating and hardening the internal surface of a tube body while subjecting the external surface of the tube body with a coolant |
| DE102013108803A1 (en) * | 2013-08-14 | 2015-02-19 | Vallourec Deutschland Gmbh | Process for producing a tempered seamless hot-worked steel tube |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE581824C (en) * | 1929-02-07 | 1933-08-03 | Heinz Niederquell | Process for the production of pre-machined, hardened or tempered workpieces |
| DE1145653B (en) * | 1954-05-25 | 1963-03-21 | Walter Reinecken Dr Ing | Process for the production of steel components, in particular arches for mining, from affordable profiles with deformation in the heat |
| DE1284978B (en) * | 1964-11-24 | 1968-12-12 | Krauss Maffei Ag | Process for tempering unalloyed and alloyed steels directly from the deformation heat |
| US3666452A (en) * | 1969-07-16 | 1972-05-30 | Jones & Laughlin Steel Corp | High-strength low-alloy steels |
| US3671336A (en) * | 1969-07-16 | 1972-06-20 | Jones & Laughlin Steel Corp | High-strength plain carbon steels having improved formability |
| US3804390A (en) * | 1971-09-08 | 1974-04-16 | Ajax Magnethermic Corp | Apparatus and method for heat-treating large diameter steel pipe |
| DE2349913B1 (en) * | 1973-10-02 | 1975-04-10 | Mannesmann Roehren Werke Ag | Device and method for quench hardening of pipes |
-
1975
- 1975-01-24 JP JP968975A patent/JPS5818404B2/en not_active Expired
-
1976
- 1976-01-17 DE DE19762601625 patent/DE2601625C3/en not_active Expired
- 1976-01-19 CA CA243,800A patent/CA1066595A/en not_active Expired
- 1976-01-20 IT IT1940176A patent/IT1054255B/en active
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108517398A (en) * | 2018-06-26 | 2018-09-11 | 安徽马钢设备检修有限公司 | A kind of Large Diameter Pipeline thin-wall tube post weld heat treatment device and its application method |
| CN108517398B (en) * | 2018-06-26 | 2023-10-27 | 安徽马钢设备检修有限公司 | Post-welding heat treatment device for large-pipe-diameter thin-wall pipe and use method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| DE2601625B2 (en) | 1979-02-22 |
| JPS5184714A (en) | 1976-07-24 |
| DE2601625C3 (en) | 1984-05-30 |
| JPS5818404B2 (en) | 1983-04-13 |
| DE2601625A1 (en) | 1976-07-29 |
| IT1054255B (en) | 1981-11-10 |
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