EP0991789B1 - Tool steel composition - Google Patents

Tool steel composition Download PDF

Info

Publication number
EP0991789B1
EP0991789B1 EP99910459A EP99910459A EP0991789B1 EP 0991789 B1 EP0991789 B1 EP 0991789B1 EP 99910459 A EP99910459 A EP 99910459A EP 99910459 A EP99910459 A EP 99910459A EP 0991789 B1 EP0991789 B1 EP 0991789B1
Authority
EP
European Patent Office
Prior art keywords
weight
tool steel
composition according
steel
steel composition
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 - Lifetime
Application number
EP99910459A
Other languages
German (de)
French (fr)
Other versions
EP0991789A1 (en
Inventor
André GRELLIER
Michel Siaut
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Aubert and Duval SA
Original Assignee
Aubert and Duval SA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Aubert and Duval SA filed Critical Aubert and Duval SA
Publication of EP0991789A1 publication Critical patent/EP0991789A1/en
Application granted granted Critical
Publication of EP0991789B1 publication Critical patent/EP0991789B1/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • 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
    • C22C38/30—Ferrous alloys, e.g. steel alloys containing chromium with cobalt
    • 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
    • C22C38/24—Ferrous alloys, e.g. steel alloys containing chromium with vanadium
    • 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
    • C21D1/19—Hardening; Quenching with or without subsequent tempering by interrupted quenching
    • C21D1/20—Isothermal quenching, e.g. bainitic hardening

Definitions

  • the present invention relates to a steel of the family known as 3% to 5% by weight of chromium used for the manufacture of resistant tools heat and working under strong constraints such as dies stamping and forging, die tools and casting molds static or pressure casting of various alloys such as alloys aluminum, copper or titanium.
  • the surface of the tools is brought into contact with materials heated to high temperatures, for example aluminum liquid at 600 ° C / 750 ° C or steel to be forged and preheated to 1200 ° C.
  • the surface of the tool is itself brought to high temperature: it follows that a thermal regime is established in the tools between the working part subjected to heating and the rest of the part cooled by natural or forced conditions.
  • the present invention first relates to a steel composition allowing good performance in service under said severe conditions.
  • composition which is the subject of the invention comprises, expressed in percentages by weight: VS 0.3 - 0.4% Cr 2.0 - 4.0% MB 0.8 - 3.0% V 0.4 - 1.0% W 1.5 - 3.0% Co 1.0 - 5.0% Yes 0 - 1.0% mn 0 - 1.0% Or 0 - 1.0% the remainder mainly consisting of iron and unavoidable impurities.
  • the composition is within the following limits: VS 0.33 - 0.37% Cr 2.58 - 3.50% MB 1.20 - 2.20% V 0.6 - 0.9% W 1.8 - 2.6% Co 1.5 - 3.0% Yes 0.2 - 0.5% mn 0.2 - 0.5% Or 0 - 0.3%
  • Carbon is the basic hardening element, its level is adjusted to obtain sufficient mechanical strength, while avoiding by excess concentration the formation of eutectic carbides at the solidification. Its content in the alloy according to the invention is 0.3-0.4% by weight, preferably 0.33-0.37% by weight.
  • Chromium and molybdenum contribute to hardenability and hardening after quenching and tempering by the formation of alloyed carbides during tempering heat treatments.
  • the content of these elements should not not be excessive in order not to overly favor the formation of chromium-molybdenum carbides to the detriment of vanadium carbides and tungsten.
  • the chromium content in the alloy according to the invention is 2.0-4.0% by weight, preferably 2.50-3.50% by weight, as for that of molybdenum it is 0.8-3.0% by weight, preferably 1.20-2.20% by weight.
  • Vanadium contributes to hardening during treatment of income by formation of specific carbides, which increases the structural resistance to heating, therefore to shift upwards the higher admissible temperatures in service. An excess of this element would be detrimental to the toughness by forming eutectic carbides at the solidification and the segregating nature of this element. Its content in the alloy according to the invention is 0.4-1.0% by weight, preferably 0.6-0.9% in weight.
  • Tungsten in the same way, completes the action of vanadium by the same types of mechanisms and likewise contributes to recovery compatible temperatures of use and, in the same way, an excess would be detrimental to tenacity and structural homogeneity.
  • Its content in the alloy according to the invention is 1.5-3.0% by weight, preferably 1.8-2.6% in weight.
  • Cobalt improves mechanical resistance when hot. Its content in the alloy according to the invention is 1.0-5.0% by weight, preferably 1.5-3.0% in weight.
  • the contents of silicon and manganese in the alloy according to the invention are each 0-1.0% by weight, preferably 0.20-0.50% by weight.
  • the content of nickel in the alloy according to the invention is 0-1.0% by weight, preferably 0-0.30% by weight.
  • the steel of the invention is manufactured according to the methods applicable to usual materials cited in reference.
  • the invention also relates to a process for the preparation of tool steel having the composition defined above, in which, according to a particular embodiment, an appropriate annealing treatment is practiced, before heat treatment of employment, to lead to a structure metallographic showing fine and well distributed carbides.
  • the quenching is carried out heating the room to a temperature between 1020 ° C and 1100 ° C, preferably between 1040 ° C and 1070 ° C, then cooling by quenching staged at 250 ° C / 320 ° C by any suitable means.
  • the properties sought are obtained after performing two income treatments, after quenching, the first tempering being carried out in the temperature range 550 ° C / 580 ° C, and the second in the interval 580 ° C / 680 ° C adjusted in depending on the hardness of use sought.
  • the metal produced by a steel mill process is produced conventional, a reflow by consumable electrode under vacuum or by consumable electrode under slag giving the material a cleanliness improved inclusion and better chemical homogeneity, which has the effect of increasing the toughness properties and by way of consequence of maintenance in service.
  • a test casting of a steel A according to the invention was carried out in order to carry out the various tests: VS 0.354% Cr 3.09% MB 1.36% V 0.81% W 2.26% Co 2.00% Yes 0.31% mn 0.30% Or 0.08% P 0.007% the balance being made up of iron and unavoidable impurities.
  • the different reference materials used for these tests are 5% chromium steels containing varying amounts of molybdenum and vanadium.

Abstract

The invention relates to a tool steel composition comprising, expressed in weight percentage:C 0.3%-0.4%Cr 2.0%-4.0%Mo 0.8%-3.0%V 0.4%-1.0%W 1.5%-3.0%Co 1.0%-5.0%Si 0 %-1.0%Mn 0 %-1.0%Ni 0 %-1.0%the balance being mainly constituted by iron and inevitable impurities, and also to a method of preparing the composition.

Description

La présente invention concerne un acier de la famille dite de 3% à 5% en poids de chrome utilisée pour la fabrication d'outillages résistant à la chaleur et travaillant sous de fortes contraintes tels que les matrices d'estampage et de forgeage, les outils de filières et les moules de coulée statique ou coulée sous pression d'alliages divers comme les alliages d'aluminium, de cuivre ou de titane.The present invention relates to a steel of the family known as 3% to 5% by weight of chromium used for the manufacture of resistant tools heat and working under strong constraints such as dies stamping and forging, die tools and casting molds static or pressure casting of various alloys such as alloys aluminum, copper or titanium.

De tels aciers sont alliés en chrome, molybdène et vanadium, éléments qui leur confèrent les propriétés de résistance à chaud requises. Plus précisément, ils se répartissent en trois familles de compositions dont les propriétés sont voisines, de sorte que ces trois familles sont mises en oeuvre pour les mêmes applications. Il s'agit de compositions comprenant, exprimés en poids, les éléments d'alliages suivants :

  • 5% de chrome, 1,3% de molybdène, 0,5% à 1,3% de vanadium environ, ou
  • 3% de chrome, 3% de molybdène, 0,5% de vanadium environ, ou enfin
  • 5% de chrome, 3% de molybdène, 0,8% de vanadium environ.
Such steels are alloyed with chromium, molybdenum and vanadium, elements which give them the required heat resistance properties. More precisely, they are divided into three families of compositions whose properties are similar, so that these three families are used for the same applications. These are compositions comprising, expressed by weight, the following alloying elements:
  • 5% chromium, 1.3% molybdenum, 0.5% to 1.3% vanadium approximately, or
  • 3% chromium, 3% molybdenum, approximately 0.5% vanadium, or finally
  • 5% chromium, 3% molybdenum, about 0.8% vanadium.

Certains de ces aciers sont désignés dans la nomenclature des Etats-Unis d'Amérique AISI sous les dénominations H11, H12, H13, dans la nomenclature allemande DIN sous les dénominations W1.2343, W1.2606 et W1.2344, et sont cités dans la norme française NF A 35-590.Some of these steels are designated in the nomenclature of United States of America AISI under the names H11, H12, H13, in the German DIN nomenclature under the names W1.2343, W1.2606 and W1.2344, and are cited in French standard NF A 35-590.

Lors de l'utilisation, la surface des outillages est mise en contact avec des matériaux chauffés à haute température, par exemple de l'aluminium liquide à 600°C / 750°C ou de l'acier destiné à être forgé et préchauffé à 1200°C.During use, the surface of the tools is brought into contact with materials heated to high temperatures, for example aluminum liquid at 600 ° C / 750 ° C or steel to be forged and preheated to 1200 ° C.

En conséquence, la surface de l'outillage est elle-même portée à haute température : il en résulte qu'un régime thermique s'établit dans l'outillage entre la partie travaillante soumise à l'échauffement et le reste de la pièce refroidie par des conditions naturelles ou forcées. As a result, the surface of the tool is itself brought to high temperature: it follows that a thermal regime is established in the tools between the working part subjected to heating and the rest of the part cooled by natural or forced conditions.

Dans des conditions d'utilisation sévères mettant en jeu des températures de surface élevées et des contraintes mécaniques fortes, la destruction de l'outil devient rapide selon deux principes :

  • la résistance mécanique du matériau décroít régulièrement lorsque la température s'élève,
  • le matériau perd ses propriétés initiales qui avaient été conférées par le traitement thermique préliminaire du fait que des transformations métallurgiques se produisent sous l'effet combiné des contraintes et de la température et provoquent l'abaissement, puis l'effondrement de la résistance mécanique.
Under severe conditions of use involving high surface temperatures and strong mechanical constraints, the destruction of the tool becomes rapid according to two principles:
  • the mechanical resistance of the material decreases regularly when the temperature rises,
  • the material loses its initial properties which had been conferred by the preliminary heat treatment due to the fact that metallurgical transformations occur under the combined effect of stresses and temperature and cause the lowering, then the collapse of the mechanical resistance.

On observe ainsi des détériorations rapides voire catastrophiques de ces outillages employés dans des conditions sévères, par adoucissement, fluage, déformation plastique et fatigue thermique de la surface travaillante.We observe rapid and even catastrophic deterioration in these tools used under severe conditions, by softening, creep, plastic deformation and thermal fatigue of the working surface.

La présente invention a pour premier objet une composition d'acier permettant une bonne tenue en service dans lesdites conditions sévères.The present invention first relates to a steel composition allowing good performance in service under said severe conditions.

La composition objet de l'invention comprend, exprimés en pourcentages en poids : C 0,3 - 0,4% Cr 2,0 - 4,0% Mo 0,8 - 3,0% V 0,4 - 1,0% W 1,5 - 3,0% Co 1,0 - 5,0% Si 0 - 1,0% Mn 0 - 1,0% Ni 0 - 1,0% le complément étant principalement constitué de fer et d'impuretés inévitables. The composition which is the subject of the invention comprises, expressed in percentages by weight: VS 0.3 - 0.4% Cr 2.0 - 4.0% MB 0.8 - 3.0% V 0.4 - 1.0% W 1.5 - 3.0% Co 1.0 - 5.0% Yes 0 - 1.0% mn 0 - 1.0% Or 0 - 1.0% the remainder mainly consisting of iron and unavoidable impurities.

De préférence, la composition se situe dans les limites suivantes : C 0,33 - 0,37% Cr 2,58 - 3,50% Mo 1,20 - 2,20% V 0,6 - 0,9% W 1,8 - 2,6% Co 1,5 - 3,0% Si 0,2 - 0,5% Mn 0,2 - 0,5% Ni 0 - 0,3% Preferably, the composition is within the following limits: VS 0.33 - 0.37% Cr 2.58 - 3.50% MB 1.20 - 2.20% V 0.6 - 0.9% W 1.8 - 2.6% Co 1.5 - 3.0% Yes 0.2 - 0.5% mn 0.2 - 0.5% Or 0 - 0.3%

De façon plus particulièrement préférée, la composition objet de l'invention comprend des teneurs en P, Sb, Sn et As, exprimées en pourcentages en poids, qui satisfont aux relations : P ≤ 0,008% Sb ≤ 0,002% Sn ≤ 0,003% As ≤ 0,005% tandis que la valeur exprimée par la relation de Bruscato B = (10 P + 5 Sb + 4 Sn + As) × 0,01 est au plus égale à 0,10%.More particularly preferably, the composition which is the subject of the invention comprises contents of P, Sb, Sn and As, expressed in percentages by weight, which satisfy the relationships: P ≤ 0.008% Sb ≤ 0.002% Sn ≤ 0.003% ace ≤ 0.005% while the value expressed by the Bruscato relation B = (10 P + 5 Sb + 4 Sn + As) × 0.01 is at most equal to 0.10%.

L'ensemble des éléments d'alliages dont les actions se complètent est équilibré pour donner une trempabilité suffisante nécessaire pour l'obtention de propriétés homogènes dans l'épaisseur de pièces de forte taille.All the alloying elements whose actions complement each other is balanced to give sufficient hardenability necessary for obtaining homogeneous properties in the thickness of strong parts cut.

Le carbone est l'élément durcissant de base, son niveau est ajusté pour obtenir une résistance mécanique suffisante, tout en évitant par un excès de concentration la formation de carbures eutectiques à la solidification. Sa teneur dans l'alliage selon l'invention est de 0,3-0,4% en poids, de préférence 0,33-0,37% en poids.Carbon is the basic hardening element, its level is adjusted to obtain sufficient mechanical strength, while avoiding by excess concentration the formation of eutectic carbides at the solidification. Its content in the alloy according to the invention is 0.3-0.4% by weight, preferably 0.33-0.37% by weight.

Le chrome et le molybdène contribuent à la trempabilité et au durcissement après trempe et revenu par formation de carbures alliés lors des traitements thermiques de revenu. La teneur en ces éléments ne doit pas être excessive pour ne pas favoriser exagérément la formation de carbures de chrome-molybdène au détriment des carbures de vanadium et tungstène. La teneur en chrome dans l'alliage selon l'invention est de 2,0-4,0% en poids, de préférence 2,50-3,50% en poids, quant à celle du molybdène elle est de 0,8-3,0% en poids, de préférence 1,20-2,20% en poids.Chromium and molybdenum contribute to hardenability and hardening after quenching and tempering by the formation of alloyed carbides during tempering heat treatments. The content of these elements should not not be excessive in order not to overly favor the formation of chromium-molybdenum carbides to the detriment of vanadium carbides and tungsten. The chromium content in the alloy according to the invention is 2.0-4.0% by weight, preferably 2.50-3.50% by weight, as for that of molybdenum it is 0.8-3.0% by weight, preferably 1.20-2.20% by weight.

Le vanadium contribue au durcissement lors des traitements de revenu par formation de carbures spécifiques, ce qui permet d'augmenter la résistance structurale à l'échauffement, donc de décaler vers le haut les températures supérieures admissibles en service. Un excès de cet élément serait préjudiciable à la ténacité par formation de carbures eutectiques à la solidification et par le caractère ségrégant de cet élément. Sa teneur dans l'alliage selon l'invention est de 0,4-1,0% en poids, de préférence 0,6-0,9% en poids.Vanadium contributes to hardening during treatment of income by formation of specific carbides, which increases the structural resistance to heating, therefore to shift upwards the higher admissible temperatures in service. An excess of this element would be detrimental to the toughness by forming eutectic carbides at the solidification and the segregating nature of this element. Its content in the alloy according to the invention is 0.4-1.0% by weight, preferably 0.6-0.9% in weight.

Le tungstène, de la même manière, complète l'action du vanadium par les mêmes types de mécanismes et contribue de même au relèvement des températures compatibles d'emploi et, de la même manière, un excès serait préjudiciable à la ténacité et à l'homogénéité structurale. Sa teneur dans l'alliage selon l'invention est de 1,5-3,0% en poids, de préférence 1,8-2,6% en poids.Tungsten, in the same way, completes the action of vanadium by the same types of mechanisms and likewise contributes to recovery compatible temperatures of use and, in the same way, an excess would be detrimental to tenacity and structural homogeneity. Its content in the alloy according to the invention is 1.5-3.0% by weight, preferably 1.8-2.6% in weight.

Ce sont les actions complémentaires et convenablement équilibrées de ces quatre éléments carburigènes Cr, Mo, V et W qui confèrent à l'acier de l'invention des propriétés nouvelles.These are complementary and appropriately balanced actions of these four carburetor elements Cr, Mo, V and W which give steel of the invention of new properties.

Le cobalt améliore la résistance mécanique à chaud. Sa teneur dans l'alliage selon l'invention est de 1,0-5,0% en poids, de préférence 1,5-3,0% en poids. Cobalt improves mechanical resistance when hot. Its content in the alloy according to the invention is 1.0-5.0% by weight, preferably 1.5-3.0% in weight.

Les teneurs du silicium et du manganèse dans l'alliage selon l'invention sont chacune de 0-1,0% en poids, de préférence 0,20-0,50% en poids. La teneur du nickel dans l'alliage selon l'invention est de 0-1,0% en poids, de préférence 0-0,30% en poids.The contents of silicon and manganese in the alloy according to the invention are each 0-1.0% by weight, preferably 0.20-0.50% by weight. The content of nickel in the alloy according to the invention is 0-1.0% by weight, preferably 0-0.30% by weight.

De manière plus générale, bien que l'on ne souhaite pas être lié par une quelconque théorie, on estime ainsi que l'obtention de bonnes caractéristiques pour de tels aciers dépend de l'équilibrage des éléments d'alliage ; elle résulte des propriétés individuelles de chacun des éléments, mais aussi de leur interaction.More generally, although one does not wish to be bound by any theory, it’s estimated that getting good characteristics for such steels depends on the balance of the elements alloy; it results from the individual properties of each of the elements, but also of their interaction.

L'effet du tungstène découle de la formation de carbures, dans la composition desquels cet élément intervient. Il est en compétition avec le chrome et le molybdène, sachant qu'une présominance des carbures de chrome est néfaste pour la stabilité en service.The effect of tungsten results from the formation of carbides, in the composition of which this element intervenes. It competes with the chromium and molybdenum, knowing that a predominance of carbides of chrome is detrimental to stability in service.

Cependant :

  • la nature cristallographique des carbures formés selon les aciers est encore mal connue de nos jours,
  • l'effet de ces carbures sur les propriétés et la stabilité structurale ne sont connus que dans les grandes lignes.
However:
  • the crystallographic nature of the carbides formed according to the steels is still poorly understood today,
  • the effect of these carbides on the properties and the structural stability are only known in broad outline.

L'acier de l'invention est fabriqué selon les procédés applicables aux matériaux usuels cités en référence.The steel of the invention is manufactured according to the methods applicable to usual materials cited in reference.

L'invention a également pour objet un procédé pour la préparation d'acier à outils ayant la composition définie ci-dessus, dans lequel, selon un mode de réalisation particulier, un traitement de recuit approprié est pratiqué, avant traitement thermique d'emploi, pour aboutir à une structure métallographique montrant des carbures fins et bien répartis.The invention also relates to a process for the preparation of tool steel having the composition defined above, in which, according to a particular embodiment, an appropriate annealing treatment is practiced, before heat treatment of employment, to lead to a structure metallographic showing fine and well distributed carbides.

Dans un mode de réalisation particulier, on réalise la trempe en chauffant la pièce à une température comprise entre 1020°C et 1100°C, de préférence entre 1040°C et 1070°C, puis en refroidissant selon une trempe étagée à 250°C / 320°C par tout moyen adapté.In a particular embodiment, the quenching is carried out heating the room to a temperature between 1020 ° C and 1100 ° C, preferably between 1040 ° C and 1070 ° C, then cooling by quenching staged at 250 ° C / 320 ° C by any suitable means.

Dans un mode de réalisation particulier, les propriétés recherchées sont obtenues après réalisation de deux traitements de revenu, après trempe, le premier revenu étant effectué dans l'intervalle de températures 550°C / 580°C, et le second dans l'intervalle 580°C / 680°C ajusté en fonction de la dureté d'emploi recherchée.In a particular embodiment, the properties sought are obtained after performing two income treatments, after quenching, the first tempering being carried out in the temperature range 550 ° C / 580 ° C, and the second in the interval 580 ° C / 680 ° C adjusted in depending on the hardness of use sought.

Dans un autre mode particulier de réalisation du procédé selon l'invention, on réalise, à partir du métal produit par un procédé d'aciérie conventionnel, une refusion par électrode consommable sous vide ou par éléctrode consommable sous laitier conférant au matériau une propreté inclusionnaire améliorée et une meilleure homogénéité chimique, ce qui a pour effet d'augmenter les propriétés de ténacité et par voie de conséquence de tenue en service.In another particular embodiment of the method according to the invention, the metal produced by a steel mill process is produced conventional, a reflow by consumable electrode under vacuum or by consumable electrode under slag giving the material a cleanliness improved inclusion and better chemical homogeneity, which has the effect of increasing the toughness properties and by way of consequence of maintenance in service.

L'invention va à présent être illustrée au moyen des exemples qui suivent.The invention will now be illustrated by means of the examples which follow.

EXEMPLESEXAMPLES

Une coulée d'essai d'un acier A selon l'invention, dont la composition est donnée dans le tableau ci-dessous, a été réalisée afin de procéder aux différents essais : C 0,354 % Cr 3,09 % Mo 1,36 % V 0,81 % W 2,26 % Co 2,00 % Si 0,31 % Mn 0,30 % Ni 0,08 % P 0,007 % le complément étant constitué de fer et d'impuretés inévitables.A test casting of a steel A according to the invention, the composition of which is given in the table below, was carried out in order to carry out the various tests: VS 0.354% Cr 3.09% MB 1.36% V 0.81% W 2.26% Co 2.00% Yes 0.31% mn 0.30% Or 0.08% P 0.007% the balance being made up of iron and unavoidable impurities.

Les différents matériaux de référence utilisés pour ces essais sont des aciers à 5% de chrome contenant des quantités variables de molybdène et de vanadium.The different reference materials used for these tests are 5% chromium steels containing varying amounts of molybdenum and vanadium.

Les symboles utilisés dans la suite ont les significations suivantes :

  • Rm : résistance maximum
  • Rp0,2 : limite élastique conventionnelle à 0,2%
  • HRC : dureté Rockwell
    • The symbols used in the following have the following meanings:
  • R m : maximum resistance
  • R p0.2 : conventional elastic limit at 0.2%
  • HRC: Rockwell hardness

    • Exemple 1 - Essais de traction à chaudExample 1 - Hot tensile tests

    Ces essais ont été réalisés à différentes températures sur l'acier A selon l'invention, ainsi que sur trois autres nuances classiques d'aciers à 5% de chrome contenant du molybdène et du vanadium. Les résultats sont rassemblés dans le tableau 1 suivant. Matériaux Température d'essai (°C) Rm (MPa) Rp0,2 (MPa) Visée de traitement (HRC) A 520 1092 916 46 5Cr 1.3Mo 0.5V 1088 851 A 550 918 753 42 5Cr 1.3Mo 0.5V 916 709 5Cr 3Mo 0.5V 842 664 5Cr 1.5Mo 1V 901 702 A 560 1028 830 46 5Cr 1.3Mo 0.5V 979 710 A 600 955 745 46 5Cr 1.3Mo 0.5V 796 552 These tests were carried out at different temperatures on steel A according to the invention, as well as on three other conventional grades of steel with 5% chromium containing molybdenum and vanadium. The results are collated in Table 1 below. Materials Test temperature (° C) R m (MPa) R p0.2 (MPa) Treatment Target (HRC) AT 520 1092 916 46 5Cr 1.3Mo 0.5V 1088 851 AT 550 918 753 42 5Cr 1.3Mo 0.5V 916 709 5Cr 3Mo 0.5V 842 664 5Cr 1.5Mo 1V 901 702 AT 560 1028 830 46 5Cr 1.3Mo 0.5V 979 710 AT 600 955 745 46 5Cr 1.3Mo 0.5V 796 552

    Comparativement aux matériaux de référence, on observe que la résistance à chaud décrite par l'essai de traction est améliorée, en particulier dès que la température d'emploi dépasse 550°C.Compared to the reference materials, we observe that the hot resistance described by the tensile test is improved, in especially when the operating temperature exceeds 550 ° C.

    Exemple 2 - Essais de traction à chaud après maintien à la températureEXAMPLE 2 Hot Tensile Tests After Maintaining the Temperature

    Ces essais ont été réalisés à la température de 550°C, après un maintien à 550°C pendant 50 heures, sur l'acier A selon l'invention ainsi que sur les trois autres nuances précédemment décrites dans l'exemple 1. Les résultats sont rassemblés dans le tableau 2 suivant. Matériaux Température d'essai (°C) ΔRm (MPa) ΔRp0,2 (MPa) Visée de traitement (HRC) A 550 -15 -13 42 5Cr 1.3Mo 0.5V -50 -40 42 5Cr 3Mo 0.5V -18 -41 42 5Cr 1.5Mo 1V -101 -104 42 These tests were carried out at a temperature of 550 ° C., after being kept at 550 ° C. for 50 hours, on steel A according to the invention as well as on the three other grades previously described in Example 1. The results are collated in table 2 below. Materials Test temperature (° C) ΔR m (MPa) ΔR p0.2 (MPa) Treatment Target (HRC) AT 550 -15 -13 42 5Cr 1.3Mo 0.5V -50 -40 42 5Cr 3Mo 0.5V -18 -41 42 5Cr 1.5Mo 1V -101 -104 42

    De la même manière, on observe que la résistance à chaud décrite par l'essai de traction est moins altérée par un maintien prolongé pendant 50 heures à la température d'emploi pour l'acier selon l'invention que pour les aciers de référence.In the same way, it is observed that the hot resistance described by the tensile test is less affected by prolonged maintenance for 50 hours at the operating temperature for the steel according to the invention than for reference steels.

    Exemple 3 - Essais de rupture sous contrainteExample 3 - Stress rupture tests

    Ces essais ont été réalisés sur l'acier A selon l'invention, ainsi que sur une autre nuance d'acier à 5% de chrome, 1,2% de molybdène et 0,5% de vanadium et avaient pour but de déterminer la contrainte nécessaire pour obtenir une rupture des éprouvettes en 100 heures. Les résultats sont rassemblés dans le tableau 3 suivant. Matériaux Température d'essai (°C) Contrainte (MPa) Traité pour (HRC) 520 695 A 560 555 42 600 360 520 795 A 560 610 46 600 400 520 670 5Cr 1.2Mo 0.5V 560 420 46 600 195 520 795 5Cr 1.2Mo 0.5V 560 425 50 600 188 These tests were carried out on steel A according to the invention, as well as on another steel grade with 5% chromium, 1.2% molybdenum and 0.5% vanadium and were intended to determine the stress necessary to obtain a rupture of the test pieces in 100 hours. The results are collated in Table 3 below. Materials Test temperature (° C) Stress (MPa) Treaty for (HRC) 520 695 AT 560 555 42 600 360 520 795 AT 560 610 46 600 400 520 670 5Cr 1.2Mo 0.5V 560 420 46 600 195 520 795 5Cr 1.2Mo 0.5V 560 425 50 600 188

    De la même manière que précédemment, on observe que la tenue en fluage exprimée par la contrainte conduisant à la rupture en 100 heures, est supérieure pour l'acier selon l'invention.In the same way as above, we observe that the holding creep expressed by the stress leading to rupture in 100 hours, is superior for the steel according to the invention.

    Exemple 4 - Essais de déformation sous contrainteEXAMPLE 4 Stress Deformation Tests

    Ces essais ont été réalisés sur l'acier A selon l'invention, ainsi que sur la même nuance d'acier que celle utilisée dans l'exemple 3 et avaient pour but de déterminer la contrainte nécessaire pour obtenir une déformation de 1% des éprouvettes en 100 heures. Les résultats sont rassemblés dans le tableau 4 suivant. Matériaux Température d'essai (°C) Contrainte (MPa) Traité pour (HRC) A 560 500 42 A 560 640 46 5Cr 1.2Mo 0.5V 560 350 46 5Cr 1.2Mo 0.5V 560 370 50 These tests were carried out on steel A according to the invention, as well as on the same steel grade as that used in Example 3 and were intended to determine the stress necessary to obtain a deformation of 1% of the test pieces in 100 hours. The results are collated in Table 4 below. Materials Test temperature (° C) Stress (MPa) Treaty for (HRC) AT 560 500 42 AT 560 640 46 5Cr 1.2Mo 0.5V 560 350 46 5Cr 1.2Mo 0.5V 560 370 50

    De la même manière que précédemment, on observe que la tenue en fluage exprimée par la contrainte conduisant à 1% de déformation en 100 heures, est supérieure pour l'acier selon l'invention.In the same way as above, we observe that the holding in creep expressed by the stress leading to 1% of deformation in 100 hours is greater for the steel according to the invention.

    Il va de soi que les formes de réalisation de la composition d'acier à outils selon l'invention qui ont été décrites ci-dessus ont été données à titre purement indicatif et nullement limitatif, et que de nombreuses modifications peuvent être facilement apportées par l'homme de l'art sans pour autant sortir du cadre de l'invention.It goes without saying that the embodiments of the steel composition to tools according to the invention which have been described above have been given as purely indicative and in no way limiting, and that many modifications can be easily made by those skilled in the art without however, depart from the scope of the invention.

    Claims (13)

    1. Tool steel composition comprising, expressed in weight percentage: C 0.3% - 0.4% Cr 2.0% - 4.0% Mo 0.8% - 3.0% V 0.4% - 1.0% W 1.5% - 3.0% Co 1.0% - 5.0% Si 0 % - 1.0% Mn 0 % - 1.0% Ni 0 % - 1.0%
      the balance being mainly constituted by iron and inevitable impurities.
    2. Tool steel composition according to claim 1, comprising, expressed in weight percentages: C 0.33% - 0.37% Cr 2.58% - 3.50% Mo 1.20% - 2.20% V 0.60% - 0.90%
    3. Tool steel composition according to claim 1 or claim 2, characterized in that the concentrations in said composition of P, Sb, Sn, and As, expressed in weight percentages satisfy the following relationships: P ≤ 0.008% Sb ≤ 0.002% Sn ≤ 0.003% As ≤ 0.005%
      while the value given by Bruscato's relationship: B = (10P + 5Sb + 4Sn = AS) × 0.01 is at most equal to 0.10%.
    4. Tool steel composition according to claim 1, characterized in that it comprises 1.8% to 2.6% by weight of tungsten.
    5. Tool steel composition according to claim 1, characterized in that it comprises 1.5% to 3.0% by weight of cobalt.
    6. Tool steel composition according to claim 1, characterized in that it comprises 0.20% to 0.50% by weight of silicon.
    7. Tool steel composition according to claim 1, characterized in that it comprises 0.20% to 0.50% by weight of manganese.
    8. Tool steel composition according to claim 1, characterized in that it comprises less than 0.30% by weight of nickel.
    9. Method of preparing a tool steel having the composition according to claim 1, characterized in that it includes quenching comprising:
      heating the steel to temperatures lying in the range 1020°C to 1100°C; and
      step quenching at temperatures lying in the range 250°C to 320°C.
    10. Method according to claim 9, characterized in that it includes quenching comprising:
      heating the steel to temperatures lying in the range 1040°C to 1070°C; and
      step quenching at temperatures lying in the range 250°C to 320°C.
    11. Method according to claim 9 or claim 10, characterized in that the steel is subjected to tempering at temperatures lying in the range 550°C to 580°C, after the quenching operation.
    12. Method according to claim 11, characterized in that the steel is subjected to second tempering at temperatures lying in the range 580°C to 680°C, after the first tempering.
    13. Method of preparing a tool steel of the composition according to any claims 1 to 8, characterized in that it includes remelting by a consumable electrode under a vacuum or by a consumable electrode under slag.
    EP99910459A 1998-04-02 1999-03-30 Tool steel composition Expired - Lifetime EP0991789B1 (en)

    Applications Claiming Priority (3)

    Application Number Priority Date Filing Date Title
    FR9804122 1998-04-02
    FR9804122A FR2777023B1 (en) 1998-04-02 1998-04-02 COMPOSITION OF TOOL STEEL
    PCT/FR1999/000735 WO1999051788A1 (en) 1998-04-02 1999-03-30 Tool steel composition

    Publications (2)

    Publication Number Publication Date
    EP0991789A1 EP0991789A1 (en) 2000-04-12
    EP0991789B1 true EP0991789B1 (en) 2003-05-02

    Family

    ID=9524794

    Family Applications (1)

    Application Number Title Priority Date Filing Date
    EP99910459A Expired - Lifetime EP0991789B1 (en) 1998-04-02 1999-03-30 Tool steel composition

    Country Status (9)

    Country Link
    US (1) US6280685B1 (en)
    EP (1) EP0991789B1 (en)
    AT (1) ATE239103T1 (en)
    BR (1) BR9906337A (en)
    CA (1) CA2292742A1 (en)
    DE (2) DE991789T1 (en)
    ES (1) ES2198903T3 (en)
    FR (1) FR2777023B1 (en)
    WO (1) WO1999051788A1 (en)

    Families Citing this family (6)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    ATE292199T1 (en) 1999-12-07 2005-04-15 Timken Co CARBURIZING, LOW CARBON AND LOW CHROME FAST WORK STEELS
    FR2858331B1 (en) * 2003-08-01 2006-12-01 Aubert Et Duval SURFACE IN CONTACT WITH TITANIUM OR TITANIUM ALLOY
    US7700210B2 (en) * 2005-05-10 2010-04-20 Bloom Energy Corporation Increasing thermal dissipation of fuel cell stacks under partial electrical load
    CN101717892B (en) * 2009-12-14 2011-07-20 浙江正达模具有限公司 Hot die steel and tempering process thereof
    CN110157984B (en) * 2019-05-29 2020-04-10 唐山志威科技有限公司 High-uniformity high-polishing type plastic die steel ZW636 and preparation method thereof
    CN111690800B (en) * 2020-06-16 2022-02-18 北京首钢吉泰安新材料有限公司 Steel for cone pulley of wire drawing machine, preparation method of steel, cone pulley of wire drawing machine and application of cone pulley

    Family Cites Families (7)

    * Cited by examiner, † Cited by third party
    Publication number Priority date Publication date Assignee Title
    DE2149697A1 (en) * 1970-10-08 1972-04-13 Allegheny Ludlum Ind Inc Improved steel, especially for hot forming tools
    SE364997B (en) * 1972-07-17 1974-03-11 Bofors Ab
    JPS5436893B2 (en) * 1973-11-28 1979-11-12
    JPS516117A (en) * 1974-07-06 1976-01-19 Daido Steel Co Ltd TAINETSUSHOGEKISEIOKAIRYOSHITA KOJINSEITEITANKABUTSUKEINETSUKANKOGUKO
    JPS5534687A (en) * 1978-09-04 1980-03-11 Hitachi Metals Ltd Precipitation hardening type hot working tool steel
    JPH03134135A (en) * 1989-10-18 1991-06-07 Hitachi Metals Ltd Tool steel for hot working
    JPH04318148A (en) * 1991-04-18 1992-11-09 Hitachi Metals Ltd Tool steel for hot working

    Also Published As

    Publication number Publication date
    CA2292742A1 (en) 1999-10-14
    US6280685B1 (en) 2001-08-28
    FR2777023A1 (en) 1999-10-08
    ATE239103T1 (en) 2003-05-15
    DE69907358T2 (en) 2004-03-25
    WO1999051788A1 (en) 1999-10-14
    EP0991789A1 (en) 2000-04-12
    FR2777023B1 (en) 2000-06-16
    DE69907358D1 (en) 2003-06-05
    DE991789T1 (en) 2001-01-11
    BR9906337A (en) 2000-10-03
    ES2198903T3 (en) 2004-02-01

    Similar Documents

    Publication Publication Date Title
    EP0792944B1 (en) Steel, suitable for manufacture of injection molds for plastics
    CA2607446C (en) Tempered martensitic steel, method of producing a part from said steel and part thus obtained
    CA2694844C (en) Hardened martensitic steel having a low or zero content of cobalt, process for manufacturing a part from this steel, and part thus obtained
    CA2730520C (en) Hardened martensitic steel having a low cobalt content, process for manufacturing a part from this steel, and part thus obtained
    FR2881144A1 (en) PROCESS FOR MANUFACTURING FERRO-CARBON-MANGANIZED AUSTENITIC STEEL TILES HAVING HIGH RESISTANCE TO DELAYED CRACKING, AND SHEETS THUS PRODUCED
    FR2885141A1 (en) Hardened martensitic steel contains amounts of carbon, cobalt, chrome and aluminum with traces of other minerals
    FR2516942A1 (en)
    EP0991789B1 (en) Tool steel composition
    FR2774098A1 (en) Steel for a divisible mechanical part, especially for two-piece internal combustion engine crank arm, manufacture by brittle fracture
    JPH1017985A (en) High strength steel excellent in hydrogen embrittlement resistance and its production
    EP3274483B1 (en) Parts with a bainitic structure having high strength properties and manufacturing process
    CA2714218C (en) Process for manufacturing austenitic stainless steel plate having high mechanical properties, and plate thus obtained
    JPH1161351A (en) High hardness martensite-based stainless steel superior in workability and corrosion resistance
    EP0388283A1 (en) Stainless ferritic steel and process for manufacturing this steel
    EP0663018B1 (en) Tool steel compositions
    WO1985004906A1 (en) Method for producing steel bars or rod wire and corresponding products
    JPH11302778A (en) Low ductility non-heat treated steel excellent in machinability
    BE384337A (en)
    BE508731A (en)
    BE389719A (en)

    Legal Events

    Date Code Title Description
    PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

    Free format text: ORIGINAL CODE: 0009012

    17P Request for examination filed

    Effective date: 19991217

    AK Designated contracting states

    Kind code of ref document: A1

    Designated state(s): AT DE ES FR GB IT NL SE

    TCAT At: translation of patent claims filed
    DET De: translation of patent claims
    GRAH Despatch of communication of intention to grant a patent

    Free format text: ORIGINAL CODE: EPIDOS IGRA

    GRAH Despatch of communication of intention to grant a patent

    Free format text: ORIGINAL CODE: EPIDOS IGRA

    GRAA (expected) grant

    Free format text: ORIGINAL CODE: 0009210

    AK Designated contracting states

    Designated state(s): AT DE ES FR GB IT NL SE

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: NL

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20030502

    Ref country code: GB

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20030502

    REG Reference to a national code

    Ref country code: GB

    Ref legal event code: FG4D

    Free format text: NOT ENGLISH

    REF Corresponds to:

    Ref document number: 69907358

    Country of ref document: DE

    Date of ref document: 20030605

    Kind code of ref document: P

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: SE

    Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT

    Effective date: 20030802

    NLV1 Nl: lapsed or annulled due to failure to fulfill the requirements of art. 29p and 29m of the patents act
    GBV Gb: ep patent (uk) treated as always having been void in accordance with gb section 77(7)/1977 [no translation filed]

    Effective date: 20030502

    REG Reference to a national code

    Ref country code: ES

    Ref legal event code: FG2A

    Ref document number: 2198903

    Country of ref document: ES

    Kind code of ref document: T3

    PLBE No opposition filed within time limit

    Free format text: ORIGINAL CODE: 0009261

    STAA Information on the status of an ep patent application or granted ep patent

    Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

    26N No opposition filed

    Effective date: 20040203

    REG Reference to a national code

    Ref country code: FR

    Ref legal event code: TP

    Ref country code: FR

    Ref legal event code: CJ

    Ref country code: FR

    Ref legal event code: CD

    Ref country code: FR

    Ref legal event code: CA

    PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

    Ref country code: ES

    Payment date: 20080319

    Year of fee payment: 10

    PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

    Ref country code: AT

    Payment date: 20080220

    Year of fee payment: 10

    PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

    Ref country code: DE

    Payment date: 20080311

    Year of fee payment: 10

    PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

    Ref country code: IT

    Payment date: 20080329

    Year of fee payment: 10

    PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

    Ref country code: FR

    Payment date: 20080317

    Year of fee payment: 10

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: AT

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20090330

    REG Reference to a national code

    Ref country code: FR

    Ref legal event code: ST

    Effective date: 20091130

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: DE

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20091001

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: FR

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20091123

    REG Reference to a national code

    Ref country code: ES

    Ref legal event code: FD2A

    Effective date: 20090331

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: ES

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20090331

    PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

    Ref country code: IT

    Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

    Effective date: 20090330