CA1062916A - Method of introducing alkaline-earth treating agents into steel melts - Google Patents
Method of introducing alkaline-earth treating agents into steel meltsInfo
- Publication number
- CA1062916A CA1062916A CA224,781A CA224781A CA1062916A CA 1062916 A CA1062916 A CA 1062916A CA 224781 A CA224781 A CA 224781A CA 1062916 A CA1062916 A CA 1062916A
- Authority
- CA
- Canada
- Prior art keywords
- melt
- agent
- steel
- process defined
- treatment
- 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
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/064—Dephosphorising; Desulfurising
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A method of introducing alkaline-earth metal treating agents into steel melts in a deoxidized or nondeoxidized state wherein a siliceous-oxide-free slag is applied to the melt and the treating agent in finely-divided form is blown into the melt in a carrier gas. The treating agent is introduced at a depth of greater than 2000 mm, preferably about 2700 mm.
A method of introducing alkaline-earth metal treating agents into steel melts in a deoxidized or nondeoxidized state wherein a siliceous-oxide-free slag is applied to the melt and the treating agent in finely-divided form is blown into the melt in a carrier gas. The treating agent is introduced at a depth of greater than 2000 mm, preferably about 2700 mm.
Description
D6Z9~6 ~ .
Field of the In~ention The present invention relates to the treat~
ment of steel melts and, mora particularly, to the treatment of steel melts wi~h alXaline-earth-metal trea~ing agents.
Back round of the Invention ,g ~
It ha~ been known heretofore in steel mQ~allurgy to treat s~eel melts in a deoxidized or nondeoxldized sta~ with treating agents con-taining alkaline-earth me~als. Gcnerally the all~line-earth metals are ~he elem~ntal or pure m~tals or are provided in mixtures, compounds or alloys.
The moBt com~on alkaline-ea~th metals used for this purpose ar~ calcium and m~gnesium and typicaL
treatmen~ agents include calcium carbide, calclum--silicon (CaSi) or calcium ferrosilicon which consists o 30% by weight calcium, 60~/o by w~ight silicon and 10~/o by weigh~ iron.
Other trestment agents include in addi~ion ~o the calcium or magnesium and apart from silicon, substances such as aluminum and manganeseO
-1- ~ ".
~06Z9~6 The treatm~nt agent is generally blown lnto the melt at a depth of 2000 mm or more to increase the degree o effec~i~eness and the reaction of the ~rea~ing agent with the 1.nelt~
The treatment serves to purify the melt by re-ducing the oxygen content and the content of oxidic im-purities, improves the elimination of sulfides which may remain aftsr desulfurization, etc.
For the mDst part the treatment quantities are the ~oichiometric requirement and substan~ially ~o excess unreacted alkaline-earth-metal treat~ent agent remains in the meltO
In the conventional systems, substantially only deoxidized steal m~l~s are treated to obtain m~xlmum utilization .-o~ the all~line-car~h treating agentO Howeve~, it has been recognized that the introduction of the entire quantity of the alkaline-earth treating agent into ~he mel~ in a single administration results in volatillzation of this agent and hence it has been proposed to control the ra~e of addition ~:
so that at any instant in time the quantity which is added is equal to the quantity which reactsO The reac~ion speed depends on the thermodynamic and reaction-kinetic paramet~rs of the total system. With this approach one is able to achieve excellent utllization of the alkaline-eartll treating agen~9 effective ductility and elongation to brealc and the like. However, it is not possible to furtller improve the OGZ9~6 ~hrinkage and viscosity characteristics~ -Ob ects of the Inv ntion It is the principal object of the present in-ven~ion to provide a method of or process for treating a steel melt with an all~line-earth treating agent which o~
i5 applicable to deoxldized4nondeoxidized steel melts and which improv~ the ductllity and break contraction char-acteristics of the steel and is also capable o improving the i80tropy 0~ the systemO
Descript~on of the Inventlon Thi~ object and other which will become apparsnt her~ina~ter ar~ attained, in accordance w~th th& invention, ..
by a process for introducing allcaline-earth treating agents into a steel melt whereby the st~el melt ~in a deoxidized or nondeoxidized state) i~ introdu¢sd into a casting ladle with a siliceou -oxlde-~ree lining, is covered with a synthetlc slliceous-oxide~ree slag, and is ~rea~ed with the requisite quan~ity of alkaline-earth metal treating agent in finely divided form by blowing the treating agent in a neutral carrier gas (e.g. argon~ into the steel m~lto The i~vention resides in that the necessary quanti~y _ of allualine-earth treating ag~nt is introduced in deficit or in reduced amount below that dictated by reaction equilibrium and over a longer period ~han i~ otherwi~e requiredO In oth~r words if the quantity Q of the trea~lng ~o62~6 agent is stoichiometrically required by the melt and the quantity i9 introduced at a rate R ~ which corresponds ~o the rate at ~Jhich the treating agenS is capable of reacting with the sy~tem under the thermodynamic and r&action-kinetic condltions mentioned abo~e, the rate R
corresponds ~o the customary rate of addltionO The trea~-ment tim~ t will then be determined by the ralation~hip t-Q/Ro According to the invention, however, the ~reating agent i8 added at a rat2 R'<R and over a period t'~t~ - :
Pre~erably ~ 5 minutes and R'~ 0.6 kg of Ca pe~ ~on of steel. The "breal~ contraction" referred ~o hereina~ter is the percent reduction in a linesr dimension a~
break caused by the application o tensile stressO Thus (break contraction) : ~ar~ x 100% in percen~ where d is the linear dim~nsion (e~g. thiclcness) prior to application :~
of tensile ~tres~ and d' is the same dimension a~ter brealc.
More specifically, th~ deficit supply of the all;aline-ear~h treating agent or agen~s m~ans tha~ the reaction rate is limi~ed by the rats of supply which is less than the maximum po~sible reaction rate under the thermodynamic : :.
peram~ters and reaction kinetic parameters and therefore substantially smaller than the rate at w~ich the treating agsnt has been supplied heretoforeO The tarm "prolonged'~
when u~ed herein to refer to the treatment time thu~ means a ~ime substantially grea~er than the treatment ~lme used for the same quantity per ton of similar trea~ing agents heretofore~
Preferably the rate R' of the addition of the treating agent ~ o629~6 in accordance with the present invention is less than 0~5R where R is the rate of addition corresponding to the maximum rate of reaction as de~ined above and the period o~ addition t according to ~he invention is at least equal to 2t where t is the addition rate for a given quantity Q o~ the treating agent which is necessary to .!
maintain the ra~e of addition R.
Surprisingly, by the deficit and prolonged addition ~f the alumin-~m earth treating agent, the ductility characteristics can be increased and it is pos~ible to lmprove substantially th~ constriction of the r~sulting metal body at break (break contraction) to 5O~/O or greater. The isotropy of th~se characteris~ics is also improvedO
It has been ~ound that the introductlon of the alkaline-earth ~rea~ing agent shouLd take place at a depth in excess of ~000 mm, preferably about 2700 mm, in the steel melt uslng lan~es or the likeO An important advantage of the invention is that it can be carried out with nondeoxidized steel melts as well 8S with deoxidized me~ts~
When the reaction is carried out wi~h nondeoxidized melts, the alkaline-earth treatlng agent is introduced prior to and up to the ~ermination o~ deoxidation in the melt~
When the treatment is carried out with deoxidized ~teel melts, the reactlon is carried out until ~he deoxidized but yet sul~ur-containing melt has reached a desul~urizatlon degree of 60%~
, , .,, ,i ; ~. : ,:
~629~L6 Deoxidation and desulfuriza~ion otherwise can be carried out by any of the conventional processes.
0~ course the trea~men~ according ~o the present in-vention can be carried out as part o the dooxida~ion or desulfuriza~ion process or both so that the lat~ar treatment and the alkaline-earth treatment according to ehe inven~ion can o~erlap. The processes may b~ con- ~ .
trolled in terms of the degree of desulfurization as .
indicat0d earlier.
~leC :
A 120 ~ons nondeoxidi~d sS~el melt has a com-position by weigh~ of:
0.17~/~ carbon ~C~
0.01% s~licon (ST3 ~ ;
0080% mangane~e (Mn~
0~01~/o phosphorous (P) ~ :
0~017% 8ulfur (S) 0.002% aluminum (Al) Balance iron tFe) The melt in a dolomlte-line casting ladle is covered with 500 kg of synthetic ~lag consisting of 80%
by weighS lime (CaO) and 20% by weight calcium fluorid~
(CaF2 ) ~
The treatlng agent was 400 kg of c~lcium-silicon (30% by welght calcium, 60% by weight ~ilicon, 3% by : .... ....
~6- .
'' ". " ' , ", "- ~ , ," ~ ".",.. ......
1~;)6Z9~6 weight aluminum, balance iron) and was introduced in ~.
powder ~orm using aluminum as a carrier gas and through lances to a depth oE about 2600 mm below the sur~ac~ of the melt over a period of over twelv~ minutesO
The composition of the melt af~er inj2ction of the calcium silicon wa6 0.17% by weight carbon 0.21% by weight silicon 0.~8Vb by weight manganese 0.012% by weig~t phosphorous 0.006% by weight sulfur 0.010% by weight aluminum ..
balance iron The steel mel~ was cast into ingots and rolled into 50 mm thick sheets. The break contraction-in the thi~kness direction of the sheets was 65 ~o 68O9%o . . . ~
~ .
110 tons of a deoxidiæed steel melt has a com-position of 0013% by w~ight carbon 0.41% by weigh~ silicon 1~45% by w~ight manganese 0.025% by weight phosphorous 0.017% by w2ight sulfur 0.068% by weight aluminum balance iron.
10629~i In a casting ladle a3 deqcribed in Example I, the steel ~elt was covered ~ith 450 kg of a synthetic slag consis~ing o 80% by weigh~ calcium oxide and 20%
by weight calcium fluorideO
10 kg of magnesium powder and 100 kg of ma~ne~ium ox~de powder are blown in argon into the steel .:
melt at a depth of about 2700 mm over a period of ~en minutes~
~ er the ~reatmen~ the composition of ~he melt is:
.
0013% carbon 0~40% silicon 1~45% manganese ..
00024% phosphorou~
0.007% sulfur 00045% aluminum balance iron After the steel has been rolled as described in Example 1, the breal~ge contra~tion was 50% or reO
Field of the In~ention The present invention relates to the treat~
ment of steel melts and, mora particularly, to the treatment of steel melts wi~h alXaline-earth-metal trea~ing agents.
Back round of the Invention ,g ~
It ha~ been known heretofore in steel mQ~allurgy to treat s~eel melts in a deoxidized or nondeoxldized sta~ with treating agents con-taining alkaline-earth me~als. Gcnerally the all~line-earth metals are ~he elem~ntal or pure m~tals or are provided in mixtures, compounds or alloys.
The moBt com~on alkaline-ea~th metals used for this purpose ar~ calcium and m~gnesium and typicaL
treatmen~ agents include calcium carbide, calclum--silicon (CaSi) or calcium ferrosilicon which consists o 30% by weight calcium, 60~/o by w~ight silicon and 10~/o by weigh~ iron.
Other trestment agents include in addi~ion ~o the calcium or magnesium and apart from silicon, substances such as aluminum and manganeseO
-1- ~ ".
~06Z9~6 The treatm~nt agent is generally blown lnto the melt at a depth of 2000 mm or more to increase the degree o effec~i~eness and the reaction of the ~rea~ing agent with the 1.nelt~
The treatment serves to purify the melt by re-ducing the oxygen content and the content of oxidic im-purities, improves the elimination of sulfides which may remain aftsr desulfurization, etc.
For the mDst part the treatment quantities are the ~oichiometric requirement and substan~ially ~o excess unreacted alkaline-earth-metal treat~ent agent remains in the meltO
In the conventional systems, substantially only deoxidized steal m~l~s are treated to obtain m~xlmum utilization .-o~ the all~line-car~h treating agentO Howeve~, it has been recognized that the introduction of the entire quantity of the alkaline-earth treating agent into ~he mel~ in a single administration results in volatillzation of this agent and hence it has been proposed to control the ra~e of addition ~:
so that at any instant in time the quantity which is added is equal to the quantity which reactsO The reac~ion speed depends on the thermodynamic and reaction-kinetic paramet~rs of the total system. With this approach one is able to achieve excellent utllization of the alkaline-eartll treating agen~9 effective ductility and elongation to brealc and the like. However, it is not possible to furtller improve the OGZ9~6 ~hrinkage and viscosity characteristics~ -Ob ects of the Inv ntion It is the principal object of the present in-ven~ion to provide a method of or process for treating a steel melt with an all~line-earth treating agent which o~
i5 applicable to deoxldized4nondeoxidized steel melts and which improv~ the ductllity and break contraction char-acteristics of the steel and is also capable o improving the i80tropy 0~ the systemO
Descript~on of the Inventlon Thi~ object and other which will become apparsnt her~ina~ter ar~ attained, in accordance w~th th& invention, ..
by a process for introducing allcaline-earth treating agents into a steel melt whereby the st~el melt ~in a deoxidized or nondeoxidized state) i~ introdu¢sd into a casting ladle with a siliceou -oxlde-~ree lining, is covered with a synthetlc slliceous-oxide~ree slag, and is ~rea~ed with the requisite quan~ity of alkaline-earth metal treating agent in finely divided form by blowing the treating agent in a neutral carrier gas (e.g. argon~ into the steel m~lto The i~vention resides in that the necessary quanti~y _ of allualine-earth treating ag~nt is introduced in deficit or in reduced amount below that dictated by reaction equilibrium and over a longer period ~han i~ otherwi~e requiredO In oth~r words if the quantity Q of the trea~lng ~o62~6 agent is stoichiometrically required by the melt and the quantity i9 introduced at a rate R ~ which corresponds ~o the rate at ~Jhich the treating agenS is capable of reacting with the sy~tem under the thermodynamic and r&action-kinetic condltions mentioned abo~e, the rate R
corresponds ~o the customary rate of addltionO The trea~-ment tim~ t will then be determined by the ralation~hip t-Q/Ro According to the invention, however, the ~reating agent i8 added at a rat2 R'<R and over a period t'~t~ - :
Pre~erably ~ 5 minutes and R'~ 0.6 kg of Ca pe~ ~on of steel. The "breal~ contraction" referred ~o hereina~ter is the percent reduction in a linesr dimension a~
break caused by the application o tensile stressO Thus (break contraction) : ~ar~ x 100% in percen~ where d is the linear dim~nsion (e~g. thiclcness) prior to application :~
of tensile ~tres~ and d' is the same dimension a~ter brealc.
More specifically, th~ deficit supply of the all;aline-ear~h treating agent or agen~s m~ans tha~ the reaction rate is limi~ed by the rats of supply which is less than the maximum po~sible reaction rate under the thermodynamic : :.
peram~ters and reaction kinetic parameters and therefore substantially smaller than the rate at w~ich the treating agsnt has been supplied heretoforeO The tarm "prolonged'~
when u~ed herein to refer to the treatment time thu~ means a ~ime substantially grea~er than the treatment ~lme used for the same quantity per ton of similar trea~ing agents heretofore~
Preferably the rate R' of the addition of the treating agent ~ o629~6 in accordance with the present invention is less than 0~5R where R is the rate of addition corresponding to the maximum rate of reaction as de~ined above and the period o~ addition t according to ~he invention is at least equal to 2t where t is the addition rate for a given quantity Q o~ the treating agent which is necessary to .!
maintain the ra~e of addition R.
Surprisingly, by the deficit and prolonged addition ~f the alumin-~m earth treating agent, the ductility characteristics can be increased and it is pos~ible to lmprove substantially th~ constriction of the r~sulting metal body at break (break contraction) to 5O~/O or greater. The isotropy of th~se characteris~ics is also improvedO
It has been ~ound that the introductlon of the alkaline-earth ~rea~ing agent shouLd take place at a depth in excess of ~000 mm, preferably about 2700 mm, in the steel melt uslng lan~es or the likeO An important advantage of the invention is that it can be carried out with nondeoxidized steel melts as well 8S with deoxidized me~ts~
When the reaction is carried out wi~h nondeoxidized melts, the alkaline-earth treatlng agent is introduced prior to and up to the ~ermination o~ deoxidation in the melt~
When the treatment is carried out with deoxidized ~teel melts, the reactlon is carried out until ~he deoxidized but yet sul~ur-containing melt has reached a desul~urizatlon degree of 60%~
, , .,, ,i ; ~. : ,:
~629~L6 Deoxidation and desulfuriza~ion otherwise can be carried out by any of the conventional processes.
0~ course the trea~men~ according ~o the present in-vention can be carried out as part o the dooxida~ion or desulfuriza~ion process or both so that the lat~ar treatment and the alkaline-earth treatment according to ehe inven~ion can o~erlap. The processes may b~ con- ~ .
trolled in terms of the degree of desulfurization as .
indicat0d earlier.
~leC :
A 120 ~ons nondeoxidi~d sS~el melt has a com-position by weigh~ of:
0.17~/~ carbon ~C~
0.01% s~licon (ST3 ~ ;
0080% mangane~e (Mn~
0~01~/o phosphorous (P) ~ :
0~017% 8ulfur (S) 0.002% aluminum (Al) Balance iron tFe) The melt in a dolomlte-line casting ladle is covered with 500 kg of synthetic ~lag consisting of 80%
by weighS lime (CaO) and 20% by weight calcium fluorid~
(CaF2 ) ~
The treatlng agent was 400 kg of c~lcium-silicon (30% by welght calcium, 60% by weight ~ilicon, 3% by : .... ....
~6- .
'' ". " ' , ", "- ~ , ," ~ ".",.. ......
1~;)6Z9~6 weight aluminum, balance iron) and was introduced in ~.
powder ~orm using aluminum as a carrier gas and through lances to a depth oE about 2600 mm below the sur~ac~ of the melt over a period of over twelv~ minutesO
The composition of the melt af~er inj2ction of the calcium silicon wa6 0.17% by weight carbon 0.21% by weight silicon 0.~8Vb by weight manganese 0.012% by weig~t phosphorous 0.006% by weight sulfur 0.010% by weight aluminum ..
balance iron The steel mel~ was cast into ingots and rolled into 50 mm thick sheets. The break contraction-in the thi~kness direction of the sheets was 65 ~o 68O9%o . . . ~
~ .
110 tons of a deoxidiæed steel melt has a com-position of 0013% by w~ight carbon 0.41% by weigh~ silicon 1~45% by w~ight manganese 0.025% by weight phosphorous 0.017% by w2ight sulfur 0.068% by weight aluminum balance iron.
10629~i In a casting ladle a3 deqcribed in Example I, the steel ~elt was covered ~ith 450 kg of a synthetic slag consis~ing o 80% by weigh~ calcium oxide and 20%
by weight calcium fluorideO
10 kg of magnesium powder and 100 kg of ma~ne~ium ox~de powder are blown in argon into the steel .:
melt at a depth of about 2700 mm over a period of ~en minutes~
~ er the ~reatmen~ the composition of ~he melt is:
.
0013% carbon 0~40% silicon 1~45% manganese ..
00024% phosphorou~
0.007% sulfur 00045% aluminum balance iron After the steel has been rolled as described in Example 1, the breal~ge contra~tion was 50% or reO
Claims (7)
1. A process for the treatment of a steel melt with an alkaline-earth metal treating agent which comprises the steps of:
(a) forming a deoxidized or nondeoxidized steel melt in a ladle lined with a material free from siliceous oxide;
(b) covering said melt with a synthetic siliceous--oxide-free slag; and (c) injecting into said melt a quantity of said treatment agent equal to the quantity thereof which stoichio-metriccally reacts with oxygen and sulfur therein, the injec-tion being effected at a rate less than the maximum rate of re-action of said melt with said agent and over a period in excess of the time required for said quantity to react with said melt under the thermodynamic and reaction-kinetic parameters preva-lent therein.
(a) forming a deoxidized or nondeoxidized steel melt in a ladle lined with a material free from siliceous oxide;
(b) covering said melt with a synthetic siliceous--oxide-free slag; and (c) injecting into said melt a quantity of said treatment agent equal to the quantity thereof which stoichio-metriccally reacts with oxygen and sulfur therein, the injec-tion being effected at a rate less than the maximum rate of re-action of said melt with said agent and over a period in excess of the time required for said quantity to react with said melt under the thermodynamic and reaction-kinetic parameters preva-lent therein.
2. The process defined in claim 1 wherein said agent is injected into said melt in a neutral carrier gas at a depth at least 2000 mm below the surface of said melt.
3. The process defined in claim 1 or claim 2 wherein said depth is about 2700 mm below the surface of said melt.
4. The process defined in claim 1 or claim 2 wherein said melt consists of nondeoxidized steel and is deoxidized during the treatment with said agent, said agent being intro-duced at least over a period corresponding to the ending of deoxidization in said melt.
5. The process defined in claim 1 or claim 2 wherein said melt is a deoxidized steel melt and said agent is introduced until the degree of desulfurization of said melt has attained 60%.
6. The process defined in claim 1 or claim 2 wherein the treatment agent is capable of both deoxidization and puriffi-cation of said melt.
7. The process defined in claim 1 or claim 2 wherein the treatment agent is injected over a period at least twice as long as is necessary for said quantity to react at said maximum rate and sufficient to effect at least 60% desulfurization of the melt.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19742419176 DE2419176B2 (en) | 1974-04-20 | 1974-04-20 | METHOD OF ADDING ALKALINE EARTH TREATMENT AGENTS TO STEEL MELT |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1062916A true CA1062916A (en) | 1979-09-25 |
Family
ID=5913476
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA224,781A Expired CA1062916A (en) | 1974-04-20 | 1975-04-16 | Method of introducing alkaline-earth treating agents into steel melts |
Country Status (17)
| Country | Link |
|---|---|
| JP (1) | JPS50143716A (en) |
| AR (1) | AR204354A1 (en) |
| AU (1) | AU8007775A (en) |
| BE (1) | BE828016A (en) |
| BR (1) | BR7502384A (en) |
| CA (1) | CA1062916A (en) |
| DD (1) | DD117251A5 (en) |
| DE (1) | DE2419176B2 (en) |
| ES (1) | ES436756A1 (en) |
| FR (1) | FR2268079A1 (en) |
| GB (1) | GB1450013A (en) |
| IN (1) | IN143231B (en) |
| IT (1) | IT1037433B (en) |
| NL (1) | NL7504252A (en) |
| PL (1) | PL93831B1 (en) |
| SE (1) | SE7504366L (en) |
| ZA (1) | ZA752179B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| USRE31676E (en) | 1982-09-29 | 1984-09-18 | Thyssen Aktiengesellschaft vorm August Thyssen-Hutte AG | Method and apparatus for dispensing a fluidizable solid from a pressure vessel |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2839637A1 (en) * | 1977-09-15 | 1979-03-22 | British Steel Corp | PROCESS FOR PRODUCING SULFURIZED STEEL |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BE795333A (en) * | 1972-03-01 | 1973-05-29 | Thyssen Niederrhein Ag | DESULFURATION PROCESS FOR FUSION STEEL AND POCKET FOR ITS IMPLEMENTATION |
-
1974
- 1974-04-20 DE DE19742419176 patent/DE2419176B2/en not_active Withdrawn
-
1975
- 1975-01-01 AR AR190D patent/AR204354A1/en active
- 1975-03-07 ZA ZA00752179A patent/ZA752179B/en unknown
- 1975-04-09 GB GB1456775A patent/GB1450013A/en not_active Expired
- 1975-04-10 IN IN725/CAL/75A patent/IN143231B/en unknown
- 1975-04-10 NL NL7504252A patent/NL7504252A/en unknown
- 1975-04-11 AU AU80077/75A patent/AU8007775A/en not_active Expired
- 1975-04-15 JP JP50044873A patent/JPS50143716A/ja active Pending
- 1975-04-16 CA CA224,781A patent/CA1062916A/en not_active Expired
- 1975-04-16 SE SE7504366A patent/SE7504366L/en unknown
- 1975-04-17 BE BE2054275A patent/BE828016A/en unknown
- 1975-04-18 DD DD185544A patent/DD117251A5/xx unknown
- 1975-04-18 ES ES436756A patent/ES436756A1/en not_active Expired
- 1975-04-18 IT IT22505/75A patent/IT1037433B/en active
- 1975-04-18 BR BR3035/75A patent/BR7502384A/en unknown
- 1975-04-18 FR FR7512118A patent/FR2268079A1/fr not_active Withdrawn
- 1975-04-18 PL PL1975179755A patent/PL93831B1/pl unknown
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| USRE31676E (en) | 1982-09-29 | 1984-09-18 | Thyssen Aktiengesellschaft vorm August Thyssen-Hutte AG | Method and apparatus for dispensing a fluidizable solid from a pressure vessel |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2268079A1 (en) | 1975-11-14 |
| IN143231B (en) | 1977-10-22 |
| SE7504366L (en) | 1975-10-21 |
| ZA752179B (en) | 1976-03-31 |
| IT1037433B (en) | 1979-11-10 |
| DE2419176B2 (en) | 1976-02-26 |
| AR204354A1 (en) | 1975-12-22 |
| DD117251A5 (en) | 1976-01-05 |
| DE2419176A1 (en) | 1975-10-30 |
| NL7504252A (en) | 1975-10-22 |
| PL93831B1 (en) | 1977-06-30 |
| JPS50143716A (en) | 1975-11-19 |
| AU8007775A (en) | 1976-10-14 |
| BE828016A (en) | 1975-08-18 |
| GB1450013A (en) | 1976-09-22 |
| BR7502384A (en) | 1976-03-09 |
| ES436756A1 (en) | 1977-01-01 |
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