CA1266790A - Process for production of high-hardness, hardened and tempered special steel and special steel alloy - Google Patents
Process for production of high-hardness, hardened and tempered special steel and special steel alloyInfo
- Publication number
- CA1266790A CA1266790A CA000468600A CA468600A CA1266790A CA 1266790 A CA1266790 A CA 1266790A CA 000468600 A CA000468600 A CA 000468600A CA 468600 A CA468600 A CA 468600A CA 1266790 A CA1266790 A CA 1266790A
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- Prior art keywords
- weight
- steel
- tempering
- alloy
- hardness
- Prior art date
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- Expired - Fee Related
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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
- C21D6/00—Heat treatment of ferrous alloys
- C21D6/02—Hardening by precipitation
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/04—Making ferrous alloys by melting
-
- 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
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/18—Hardening; Quenching with or without subsequent tempering
-
- 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
- C22C38/22—Ferrous alloys, e.g. steel alloys containing chromium 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
- C22C38/28—Ferrous alloys, e.g. steel alloys containing chromium with titanium or zirconium
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Heat Treatment Of Articles (AREA)
- Heat Treatment Of Steel (AREA)
Abstract
ABSTRACT OF THE INVENTION
The invention concerns a process for production of a high-hardness, hardened and tempered special steel and a special steel alloy. According to the invention special heat control and certain alloying elements are proposed to obtain various properties of the steel with a particular steel alloy.
The invention concerns a process for production of a high-hardness, hardened and tempered special steel and a special steel alloy. According to the invention special heat control and certain alloying elements are proposed to obtain various properties of the steel with a particular steel alloy.
Description
~26~ 361 The invention concerns a process for production of a high-hardness, hardened and tempered special steel with a high degree of hardness and strength, with simultaneously high toughness, with the following alloy base:
Carbon 0.25 to 0.45 weight %,preferably 0.25 to 0.35 weight %
Silicon 0.08 to 0.50 weight %,preferably 0.15 to 0.40 weight Manganese 0.30 to l.50 weight %,preferably 0.60 to l.00 weigl1t %
Phosphorus ~ 0.020 " %, " ~ 0.008 "
Sulfur ~ 0.020 " %, " < 0.008 "
Chromium 0.60 to l.80 " %, " 0.70 to l.40 "
Molybdenum 0.20 to 0.60 " %~ " 0.30 to 0.50 Boron < 0.006 " %, " ~ 0.003 Titaniw11 anc1/or alumini~n 0.02 to O.l50 weigl1t %, preferably 0.020 to 0.120 weight %.
Conventional high-hardness, hardened, and tempered special steels as are presently used in the fabrication of vehicle bodies for example those which are distinguished by a high degree of hardness and resistance to penetration of projectiles. These special steels generally contain a relatively hig11 carbon content of approximately 0.40 to 0.50 weight %, with a chromium content of approximately l.5 weight %, and a molybdenu1n cont~nt of approximately 0.5 weight %. ~lese steels are tempered after hardening at temperatures around 600 degrees centigrade. They possess the advantage that when welded a certain "self-healing effect" takes plac~ in the heat-aff~cted zone and that practically no zone of red~1ced har~ness occurs. In additio11, t after completion of welding the weld~d component can bo stress relieved by heat troatme11t to reduc~ residual wolding stresses and the danger of cracki11g.
~' With complicated welded structures, however, it is possible that hydrogen can cause welding crack formation and thus severe problems to occur.
For this reason, in keeping with American prototypes, steels have been introduced which have a lower carbon content of approximately 0.3 weight % and a boron content of approximately 0.003 weight % to improve weldability.
Less to obtain an effect of precipitation hardening, but rather for fixation of the nitrogen, this steel is additionally alloyed with approximately 0.15 weight % of titanium. Under certain circumstances the boron content displaces the transformation stage projection in the time-temperature transformation curve as well as commencement of :Eerrite-pearlite transformation to the right, i.e. it delays the transformation processes. As a result oE
this effect, in spite o:E the low carbon content, it is possibl~ during normal oil quenc}ling to achieve t:ransformation in the martensite stage eve with thick plating. In the literature on the subject mention is made of a "boron factor" which is a measure of the increased hardenability. This effect is enhanced with thick plating by including nickel in the alloy.
It has been found that these steels prove satisfactory for welding by virtue of a considerably reduced danger of cracking. On account of the generally very low tempering temperatures, which may, for example, be only 200 degrees centigrade, stress-relieving heat treatment after welding is not possible however. The significant disadvantage of these steels is the pronounced hardness sag, i,e. significant softening in the heat affected zone during welding. At these points projectiles can penetrate the wall. To compensate for the tempering effect, i.e. softening in the heat affected zone, one could consider alloying of micro-alloying elements which cause precipitation hardening. Metallographic investigation however has shown that with normal 7~
heat control the titanium content of the steel described leads primarily to coarse titanium carbonitrides which are practically uninvolved in the precipitation hardening. The effect of precipitation hardening is therefore minimal in the case of titanium. The element titanium is used - like aluminium as well - for fixation of the nitrogen and prevents formation of boric nitrides.
The purpose of the invention therefore is to provide a process for production of a high-hardness, high strength tempered special steel and a special steel which does not possess the disadvantagesdescribed.
Thus this invention in a first aspect provides a process for the preparation of a steel of the class described above wherein small amounts of the clelllent n:iobium are alloyecl in the steel for adclitiollal precipitation hardelling, that :is to say in a concentration of appro~imately 0.005 to 0.03 weight %, preferably 0.008 to 0.02 weight %, the steel so produced is subjected to heat treatment and hardening and tempering treatment suited to the alloy base to attain a Brinell hardness of 450 to S50 HB, preferably 475 to 525 HB which consists of austenizing at 860 degrees to 960 degrees centigrade, preferably 880 degrees to 920 degrees centigrade, quenching with water, or oil, or compressed air, and temperiIlg in the temperature range from 160 degreesto 350 degrees centigrade, preferably in the range from 180 degrees centigrade to 250 degrees centigrade, dependent on the plate thickness involved.
In the case of the steel which is the subject of the invention, instead of or in addition to -the alloying element titanium and in addition to aluminium the element niobium is used in very small proportions as alloying element. It has been established by research that the action of the element niobium as precipitation hardeni.ng element is effective from 0.005 weight ~. Above this threshold value the strengthening effect is less so that basically higher contents do not produce any further significant effect.
According to the literature on the subject,the niobium carbonitrides formed are stable at very high temperatures, whilst titanium carbonitrides are re-dissolved at a lower temperature.
Thus according to this invention, the element niobium produces in the steel, with the heat control proposed by the invention, a considerable increase in hardness by precipitation of carbides and carbonitrides in the most favourable Eorm, particle size and distribution in the matrix. This e~:Eect encourages hardness in the heat affected zone of welded joints and thus counteracts the so--calLed hclrdlless sag in the we:Lcl aEEectecl zone.
Whilst with the state of the art slow cooling in the case o:E ingot casting has the effect that the titanium carbonitrides are present in very coarse form so that the steel must be cast mainly by continuous casting, a steel produced in accordance with the process which is the subject of the invention can be cast by virtue of the alloying element niobium both by continuous casting and ingot casting.
In the case of a further useful process of the invention the steel is subjected to an elevated tempering temperature in the range from 250 to 450 degrees centigrade. As a result one achieves a Brinell hardness of 400 to 475 HB.
One useful process is characterized by the fact that a tempering temperature in the range from 350 degrees to 550 degrees centigrade is chosen as a result of which Brinell hardness values of 300 to 460 HB are achieved.
- - - ~
~ 7~ 26706-14 The subject of the invention is a useful special steel alloy characterized by the fact that on the basis of a steel with the following alloy base:
Carbon 0.25 to 0.45 weight % preferably 0.25 to 0.35 weight %
Silicon 0.08 0.50 % preferably 0.15 to 0.40 Manganese 0.30 1.50 % preferably 0.60 to 1.00 Phospllorus < 0.020 % < 0.008 Sulfur < 0.020 % < 0.008 Chromium 0.60 1.80 %. 0.70 to 1.40 Molybdenum0.20 0.60 % 0.30 to 0.50 Boron ~ 0.006 % ~ 0.003 Tita]lium and/or alulllinium 0.02 to 0.150 weigllt % preferably 0.020 to 0.120 w~ight % small (luanti~ies oE the ~lemellt nio~).ium ar~
alloye~l in the steel ~or a~ditionll precipitation hllrdening in a concelltration of approximately 0.005 to 0.03 weigllt % preferably 0.008 to 0.02 weight %.
A further useful alloy is characteri~ed by the fact that tituniwn is replaced by an increased aluminium content in the approximate concelltration of 0.020 to 0.080 weigllt % prefer.lbly from 0.030 to O.U6 - 20 weight %
The alloying element boron dev~lops its hardness increasing effect only in the state of solution in the matrix and not if it is bollded to nitrogen. For tllis reason in accordance witll the invelltion an elemellt is alloyed to the steel whicil has a very higll affinity to nitrogen e.g.
titanium. No pure titanium nitrides are formed hol~ever but titanium carbonitrides with higll proportions of carbon. The carbollitrides are the ~,J~
~667~3~
present in the secondary structure, that is to say mainly in the form of very coarse crystals of reddish colour visible at low magnification; these are without any positive significance as regards the steel properties.
A disadvantage can be seen in the fact that as a result of the element titanium part of the carbon content is uselessly bonded to titanium. By replacing the titanium content with the element aluminium in accordance with the invention only aluminium nitrides are formed and no carbides. The nitrogen of the steel is fixed to aluminium - as is necessary.
A further useful method is characterized by the fact that with the larger plate thicknesses a nickel addition of 0.5 to 2 weight % is alloyed to increase through-quenching and tempering propert:ies.
The fecltures descrlbed :in the sp~clfication ancl :in tho p.-ten-t claims can be essential for implementation of the invention both individually and in any optional combinations.
Carbon 0.25 to 0.45 weight %,preferably 0.25 to 0.35 weight %
Silicon 0.08 to 0.50 weight %,preferably 0.15 to 0.40 weight Manganese 0.30 to l.50 weight %,preferably 0.60 to l.00 weigl1t %
Phosphorus ~ 0.020 " %, " ~ 0.008 "
Sulfur ~ 0.020 " %, " < 0.008 "
Chromium 0.60 to l.80 " %, " 0.70 to l.40 "
Molybdenum 0.20 to 0.60 " %~ " 0.30 to 0.50 Boron < 0.006 " %, " ~ 0.003 Titaniw11 anc1/or alumini~n 0.02 to O.l50 weigl1t %, preferably 0.020 to 0.120 weight %.
Conventional high-hardness, hardened, and tempered special steels as are presently used in the fabrication of vehicle bodies for example those which are distinguished by a high degree of hardness and resistance to penetration of projectiles. These special steels generally contain a relatively hig11 carbon content of approximately 0.40 to 0.50 weight %, with a chromium content of approximately l.5 weight %, and a molybdenu1n cont~nt of approximately 0.5 weight %. ~lese steels are tempered after hardening at temperatures around 600 degrees centigrade. They possess the advantage that when welded a certain "self-healing effect" takes plac~ in the heat-aff~cted zone and that practically no zone of red~1ced har~ness occurs. In additio11, t after completion of welding the weld~d component can bo stress relieved by heat troatme11t to reduc~ residual wolding stresses and the danger of cracki11g.
~' With complicated welded structures, however, it is possible that hydrogen can cause welding crack formation and thus severe problems to occur.
For this reason, in keeping with American prototypes, steels have been introduced which have a lower carbon content of approximately 0.3 weight % and a boron content of approximately 0.003 weight % to improve weldability.
Less to obtain an effect of precipitation hardening, but rather for fixation of the nitrogen, this steel is additionally alloyed with approximately 0.15 weight % of titanium. Under certain circumstances the boron content displaces the transformation stage projection in the time-temperature transformation curve as well as commencement of :Eerrite-pearlite transformation to the right, i.e. it delays the transformation processes. As a result oE
this effect, in spite o:E the low carbon content, it is possibl~ during normal oil quenc}ling to achieve t:ransformation in the martensite stage eve with thick plating. In the literature on the subject mention is made of a "boron factor" which is a measure of the increased hardenability. This effect is enhanced with thick plating by including nickel in the alloy.
It has been found that these steels prove satisfactory for welding by virtue of a considerably reduced danger of cracking. On account of the generally very low tempering temperatures, which may, for example, be only 200 degrees centigrade, stress-relieving heat treatment after welding is not possible however. The significant disadvantage of these steels is the pronounced hardness sag, i,e. significant softening in the heat affected zone during welding. At these points projectiles can penetrate the wall. To compensate for the tempering effect, i.e. softening in the heat affected zone, one could consider alloying of micro-alloying elements which cause precipitation hardening. Metallographic investigation however has shown that with normal 7~
heat control the titanium content of the steel described leads primarily to coarse titanium carbonitrides which are practically uninvolved in the precipitation hardening. The effect of precipitation hardening is therefore minimal in the case of titanium. The element titanium is used - like aluminium as well - for fixation of the nitrogen and prevents formation of boric nitrides.
The purpose of the invention therefore is to provide a process for production of a high-hardness, high strength tempered special steel and a special steel which does not possess the disadvantagesdescribed.
Thus this invention in a first aspect provides a process for the preparation of a steel of the class described above wherein small amounts of the clelllent n:iobium are alloyecl in the steel for adclitiollal precipitation hardelling, that :is to say in a concentration of appro~imately 0.005 to 0.03 weight %, preferably 0.008 to 0.02 weight %, the steel so produced is subjected to heat treatment and hardening and tempering treatment suited to the alloy base to attain a Brinell hardness of 450 to S50 HB, preferably 475 to 525 HB which consists of austenizing at 860 degrees to 960 degrees centigrade, preferably 880 degrees to 920 degrees centigrade, quenching with water, or oil, or compressed air, and temperiIlg in the temperature range from 160 degreesto 350 degrees centigrade, preferably in the range from 180 degrees centigrade to 250 degrees centigrade, dependent on the plate thickness involved.
In the case of the steel which is the subject of the invention, instead of or in addition to -the alloying element titanium and in addition to aluminium the element niobium is used in very small proportions as alloying element. It has been established by research that the action of the element niobium as precipitation hardeni.ng element is effective from 0.005 weight ~. Above this threshold value the strengthening effect is less so that basically higher contents do not produce any further significant effect.
According to the literature on the subject,the niobium carbonitrides formed are stable at very high temperatures, whilst titanium carbonitrides are re-dissolved at a lower temperature.
Thus according to this invention, the element niobium produces in the steel, with the heat control proposed by the invention, a considerable increase in hardness by precipitation of carbides and carbonitrides in the most favourable Eorm, particle size and distribution in the matrix. This e~:Eect encourages hardness in the heat affected zone of welded joints and thus counteracts the so--calLed hclrdlless sag in the we:Lcl aEEectecl zone.
Whilst with the state of the art slow cooling in the case o:E ingot casting has the effect that the titanium carbonitrides are present in very coarse form so that the steel must be cast mainly by continuous casting, a steel produced in accordance with the process which is the subject of the invention can be cast by virtue of the alloying element niobium both by continuous casting and ingot casting.
In the case of a further useful process of the invention the steel is subjected to an elevated tempering temperature in the range from 250 to 450 degrees centigrade. As a result one achieves a Brinell hardness of 400 to 475 HB.
One useful process is characterized by the fact that a tempering temperature in the range from 350 degrees to 550 degrees centigrade is chosen as a result of which Brinell hardness values of 300 to 460 HB are achieved.
- - - ~
~ 7~ 26706-14 The subject of the invention is a useful special steel alloy characterized by the fact that on the basis of a steel with the following alloy base:
Carbon 0.25 to 0.45 weight % preferably 0.25 to 0.35 weight %
Silicon 0.08 0.50 % preferably 0.15 to 0.40 Manganese 0.30 1.50 % preferably 0.60 to 1.00 Phospllorus < 0.020 % < 0.008 Sulfur < 0.020 % < 0.008 Chromium 0.60 1.80 %. 0.70 to 1.40 Molybdenum0.20 0.60 % 0.30 to 0.50 Boron ~ 0.006 % ~ 0.003 Tita]lium and/or alulllinium 0.02 to 0.150 weigllt % preferably 0.020 to 0.120 w~ight % small (luanti~ies oE the ~lemellt nio~).ium ar~
alloye~l in the steel ~or a~ditionll precipitation hllrdening in a concelltration of approximately 0.005 to 0.03 weigllt % preferably 0.008 to 0.02 weight %.
A further useful alloy is characteri~ed by the fact that tituniwn is replaced by an increased aluminium content in the approximate concelltration of 0.020 to 0.080 weigllt % prefer.lbly from 0.030 to O.U6 - 20 weight %
The alloying element boron dev~lops its hardness increasing effect only in the state of solution in the matrix and not if it is bollded to nitrogen. For tllis reason in accordance witll the invelltion an elemellt is alloyed to the steel whicil has a very higll affinity to nitrogen e.g.
titanium. No pure titanium nitrides are formed hol~ever but titanium carbonitrides with higll proportions of carbon. The carbollitrides are the ~,J~
~667~3~
present in the secondary structure, that is to say mainly in the form of very coarse crystals of reddish colour visible at low magnification; these are without any positive significance as regards the steel properties.
A disadvantage can be seen in the fact that as a result of the element titanium part of the carbon content is uselessly bonded to titanium. By replacing the titanium content with the element aluminium in accordance with the invention only aluminium nitrides are formed and no carbides. The nitrogen of the steel is fixed to aluminium - as is necessary.
A further useful method is characterized by the fact that with the larger plate thicknesses a nickel addition of 0.5 to 2 weight % is alloyed to increase through-quenching and tempering propert:ies.
The fecltures descrlbed :in the sp~clfication ancl :in tho p.-ten-t claims can be essential for implementation of the invention both individually and in any optional combinations.
Claims (11)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Process for production of a high-hardness, hardened and tempered special steel with a high degree of hardness and strength, with simultaneously high toughness, with the following alloy base:
Carbon 0.25 to 0.45 weight %
Silicon 0.08 to 0.50 "
Manganese 0.30 to 1.50 "
Phosphorus ? 0.020 "
Sulphur ? 0.020 "
Chromium 0.60 to 1.80 "
Molybdenum 0.20 to 0.60 "
Boron ? 0.006 "
Titanium and/or aluminium 0.02 to 0.150 weight %
In which process, for additional precipitation hardness, small quantities of the element niobium are alloyed to the steel, in a concentration of approximately 0.005 to 0.03 weight %, and that the steel so produced is subjected to heat and hardening and tempering treatment suited to the alloy base which consists of austenizing at 860 degrees to 960 degrees centigrade, quenching with water or oil or compressed air and tempering in the temperature range from 160 degrees to 550 degrees centigrade, dependent on the plate thickness involved.
Carbon 0.25 to 0.45 weight %
Silicon 0.08 to 0.50 "
Manganese 0.30 to 1.50 "
Phosphorus ? 0.020 "
Sulphur ? 0.020 "
Chromium 0.60 to 1.80 "
Molybdenum 0.20 to 0.60 "
Boron ? 0.006 "
Titanium and/or aluminium 0.02 to 0.150 weight %
In which process, for additional precipitation hardness, small quantities of the element niobium are alloyed to the steel, in a concentration of approximately 0.005 to 0.03 weight %, and that the steel so produced is subjected to heat and hardening and tempering treatment suited to the alloy base which consists of austenizing at 860 degrees to 960 degrees centigrade, quenching with water or oil or compressed air and tempering in the temperature range from 160 degrees to 550 degrees centigrade, dependent on the plate thickness involved.
2. A process according to claim 1 wherein the alloy base has the following composition:
Carbon 0.25 - 0.35 weight %
Silicon 0.15 - 0.40 "
Manganese 0.60 - 1.00 "
Phosphorus ? 0.008 "
Sulphur ? 0.008 "
Chromium 0.70 - 1.40 "
Molybdenum 0.30 - 0.50 "
Boron ? 0.003 "
Titanium and/or aluminium 0.020 - 0.120 and wherein the amount of alloyed niobium is from 0.008 to 0.02 weight %.
Carbon 0.25 - 0.35 weight %
Silicon 0.15 - 0.40 "
Manganese 0.60 - 1.00 "
Phosphorus ? 0.008 "
Sulphur ? 0.008 "
Chromium 0.70 - 1.40 "
Molybdenum 0.30 - 0.50 "
Boron ? 0.003 "
Titanium and/or aluminium 0.020 - 0.120 and wherein the amount of alloyed niobium is from 0.008 to 0.02 weight %.
3. A process according to claims 1 or 2 wherein the heat and hardening and tempering process provides a steel having a Brinell hardness of 450 to 550 HB, which consists of austenizing at 860 to 960°C, quenching with water, oil or compressed air and tempering in the range of from 160 to 350°C, dependent upon the plate thickness involved.
4. A process according to claims 1 or 2 wherein the heat and hardening and tempering process provides a steel having a Brinell hardness of 475 to 525 HB, which consists of austenizing at 880 to 920°C, quenching with water, oil or compressed air and tempering in the range of from 180 to 250°C, dependent upon the plate thickness involved.
5. A process in accordance with claim 1 characterized by the fact that the steel is subjected to a higher tempering temperature in the range from 250 to 450 degrees centigrade.
6. A process in accordance with claim 1, characterized by the fact that the steel is subjected to a tempering temperature in the range from 350 to 550 degrees centigrade.
7. Special steel alloy with the following alloy base:
Carbon 0.25 to 0.45 weight %
Silicon 0.08 to 0.50 "
Manganese 0.30 to 1.50 "
Phosphorus ? 0.020 "
Sulphur ? 0.020 "
Chromium 0.60 to 1.80 "
Molybdenum 0.20 to 0.60 "
Boron ? 0.006 "
Titanium and/or aluminum 0.02 to 0.150 weight %
which alloy base also contains, for additional precipitation hardness, small quantities of the element niobium are alloyed to the steel, in a concentration of approximately 0.005 to 0.03 weight %, and, if required, from 0.5 to 2% by weight of nickel.
Carbon 0.25 to 0.45 weight %
Silicon 0.08 to 0.50 "
Manganese 0.30 to 1.50 "
Phosphorus ? 0.020 "
Sulphur ? 0.020 "
Chromium 0.60 to 1.80 "
Molybdenum 0.20 to 0.60 "
Boron ? 0.006 "
Titanium and/or aluminum 0.02 to 0.150 weight %
which alloy base also contains, for additional precipitation hardness, small quantities of the element niobium are alloyed to the steel, in a concentration of approximately 0.005 to 0.03 weight %, and, if required, from 0.5 to 2% by weight of nickel.
8. A special alloy steel according to claim 7 wherein the alloy base has the following composition:
Carbon 0.25 to 0.35 weight %
Silicon 0.15 to 0.40 "
Manganese 0.60 to 1.00 "
Phosphorus ? 0.008 "
Sulphur ? 0.008 "
Chromium 0.70 to 1.40 "
Molybdenum 0.30 to 0.50 weight %
Boron ? 0.003 "
Titanium and/or aluminum 0.020 to 0.120 weight %
and wherein the amount of alloyed niobium is from 0.008 to 0.02 weight %.
Carbon 0.25 to 0.35 weight %
Silicon 0.15 to 0.40 "
Manganese 0.60 to 1.00 "
Phosphorus ? 0.008 "
Sulphur ? 0.008 "
Chromium 0.70 to 1.40 "
Molybdenum 0.30 to 0.50 weight %
Boron ? 0.003 "
Titanium and/or aluminum 0.020 to 0.120 weight %
and wherein the amount of alloyed niobium is from 0.008 to 0.02 weight %.
9. Special steel alloy in accordance with claim 7 wherein titanium is replaced by an increased aluminum content, approximately in a concentration of 0.020 to 0.080 weight %.
10. Special steel alloy in accordance with claim 9 where-in titanium is replaced by an increased aluminum content, approximately in a concentration of 0.030 to 0.06 weight %.
11. Special steel alloy in accordance with claim 7 wherein in the case of the larger plate thickness the alloy add-itionally contains from 0.5 to 2 % by weight of nickel, to improve through-quenching and tempering properties.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU22584/83 | 1983-12-20 | ||
| AU22584/83A AU564998B2 (en) | 1983-12-20 | 1983-12-20 | Hardened and tempered high hardness special steels |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1266790A true CA1266790A (en) | 1990-03-20 |
Family
ID=3711772
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000468600A Expired - Fee Related CA1266790A (en) | 1983-12-20 | 1984-11-26 | Process for production of high-hardness, hardened and tempered special steel and special steel alloy |
Country Status (9)
| Country | Link |
|---|---|
| KR (1) | KR900000279B1 (en) |
| AU (1) | AU564998B2 (en) |
| BR (1) | BR8406523A (en) |
| CA (1) | CA1266790A (en) |
| EG (1) | EG16763A (en) |
| IL (1) | IL73473A (en) |
| MX (1) | MX162375A (en) |
| NZ (1) | NZ210175A (en) |
| ZA (1) | ZA849878B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4007487A1 (en) * | 1990-03-09 | 1991-09-12 | Skf Gmbh | METHOD FOR PRODUCING STEEL MACHINE ELEMENTS |
| JP3514182B2 (en) * | 1999-08-31 | 2004-03-31 | 住友金属工業株式会社 | Low Cr ferritic heat resistant steel excellent in high temperature strength and toughness and method for producing the same |
| US9410220B2 (en) * | 2012-06-19 | 2016-08-09 | Buffalo Armory Llc | Method and apparatus for treating a steel article |
| CN108374075B (en) * | 2018-03-12 | 2019-11-15 | 包头北方安全防护装备制造有限公司 | The method for controlling large-scale armour plate brake forming part quenching distortion |
-
1983
- 1983-12-20 AU AU22584/83A patent/AU564998B2/en not_active Ceased
-
1984
- 1984-10-31 MX MX203232A patent/MX162375A/en unknown
- 1984-11-09 IL IL73473A patent/IL73473A/en unknown
- 1984-11-09 NZ NZ210175A patent/NZ210175A/en unknown
- 1984-11-12 EG EG697/84A patent/EG16763A/en active
- 1984-11-26 CA CA000468600A patent/CA1266790A/en not_active Expired - Fee Related
- 1984-12-03 KR KR1019840007612A patent/KR900000279B1/en not_active IP Right Cessation
- 1984-12-18 BR BR8406523A patent/BR8406523A/en unknown
- 1984-12-19 ZA ZA849878A patent/ZA849878B/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| ZA849878B (en) | 1985-06-17 |
| KR850004998A (en) | 1985-08-19 |
| IL73473A0 (en) | 1985-02-28 |
| EG16763A (en) | 1991-08-30 |
| MX162375A (en) | 1991-05-02 |
| KR900000279B1 (en) | 1990-01-24 |
| BR8406523A (en) | 1985-10-15 |
| AU2258483A (en) | 1985-06-27 |
| AU564998B2 (en) | 1987-09-03 |
| IL73473A (en) | 1987-10-20 |
| NZ210175A (en) | 1988-03-30 |
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| Date | Code | Title | Description |
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| MKLA | Lapsed |