KR100540851B1 - Material for the manufacture of parts and tools for use at elevated temperature, method for producing the material - Google Patents

Abstract

The present invention relates to materials for heat-loaded parts and tools, methods of making and using the materials.

The present invention has a high reaction inertness, in particular high oxidation resistance and increased hardness at temperatures up to 750 ° C., where the nickel content of the alloy is " chromium content + 1.5 silicon weight%-0.12 manganese weight%-18 nitrogen weight%-30 Equal to or equivalent to the value formed by carbon weight%-6 "or up to 4.8 weight% (Ni ≥ Cr + 1.5 × Si-0.12 Mn-18 × N-30 × C-6),

0.01 to 0.25 weight% carbon (C),

0.35 to 2.5 weight percent silicon (Si),

0.4 to 4.3 weight% manganese (Mn),

16.0 to 28.0 weight percent of chromium (Cr),

15.0 to 36.0 weight percent nickel (Ni),

A composition of nitrogen (N) of 0.01 to 0.29% by weight,

It consists of a material consisting of residual iron (Fe) and an alloy containing ancillary elements and impurities, which material has a hardness of at least 230 HB formed through cold deformation.

Description

MATERIAL FOR THE MANUFACTURE OF PARTS AND TOOLS FOR USE AT ELEVATED TEMPERATURE, METHOD FOR PRODUCING THE MATERIAL}

1 is a graph showing the strength according to the degree of cold deformation of the material according to the invention at 604 ℃.

Figure 2 is a graph showing the hardness waveform at room temperature after receiving a temperature load for a long time at 600 ℃.

The present invention relates to materials having high non-reactivity, in particular high oxidation resistance and high hardness, for parts and tools subjected to heat loads.

According to DIN 50900, the reaction of metal materials by the surrounding environment to cause measurable material deformation is defined as corrosion. Corrosion can in this case take place by means of the mechanical load of the part and without the mechanical load of the part, depending on the chemical attack in different ways and at various temperatures.

Most often, surface erosion of the object is caused by electrochemical corrosion in the presence of an ion conducting phase, or by high temperature corrosion upon chemical corrosion and temperature rise. In addition, in a molten medium such as liquid glass at elevated temperatures, a corrosive attack may occur due to surface deformation of a metal part in contact with the surface.

In modern technology, parts and tool members are mostly exposed simultaneously to many different loads (loads), among which thermal and mechanical loads in particular can act alternately or dynamically (well). As a result, many times the increased corrosion conditions can be formed, which are in some cases increased by deformation of the region near the surface of the part.

The corrosion resistant heat resistant steels and alloys must have a face-centered cubic lattice structure or austenite crystal structure in order to be able to withstand temperatures above 600 ° C. This means that, in alloy technical terms, in terms of increased strength, the material in such a manner has a higher nickel content and / or cobalt content or is formed as an alloy based on nickel or cobalt. In this case, however, the chromium content must be 13% by weight or more due to chemical corrosion.

Although materials with high nickel concentrations have consistently increased mechanical strength or high material hardness, thereby improving the use properties of parts and tool members at high temperatures, for economic reasons, the nickel content is reduced to less than 36% by weight. In order to increase the corrosion resistance, it is required to increase the chromium quota of the alloy to 16% by weight or more.

Iron-based austenitic materials having a nickel content of less than 36% by weight, due to the high chromium concentration, optionally with additional corrosion protection elements, at high temperatures, such as at 600 ° C. and above Although capable of withstanding corrosive attack for a minimum required time, the material not only has low hardness but also has a similar degree of strength and limited creep properties. Despite these disadvantages, alloys according to DIN materials nos. 1.2780, 1.2782 and 1.2786, for example, are used as tools for glass processing for economic and manufacturing reasons.

The present invention therefore provides a solution, having a hardness higher than 230 HB, and having a high creep resistance and improved creep properties and similar corrosion resistance even at temperatures above 600 ° C. It is an object to provide a material.

It is also an object of the present invention to provide a method for economically manufacturing materials for parts and tools having improved use properties at high hardness and increased corrosion resistance.

Finally, the present invention aims to use an alloy based on iron as a material for heat treatment tools used at operating temperatures of 550 ° C. or higher.

The above purpose is that the nickel content of the alloy is equal to, or in some cases up to, 4.8 weight% of the value formed from "Chrome content + 1.5 silicon weight%-0.12 manganese weight%-18 nitrogen weight%-30 carbon weight%-6" Larger (Ni ≥ Cr + 1.5 × Si-0.12 Mn-18 × N-30 × C-6), substantially

0.01 to 0.25 weight% carbon (C),

0.35 to 2.5 weight percent silicon (Si),

0.4 to 4.3 weight% manganese (Mn),

16.0 to 28.0 weight percent of chromium (Cr),

15.0 to 36.0 weight percent nickel (Ni),

A composition of nitrogen (N) of 0.01 to 0.29% by weight,

It is achieved through a material of the type mentioned in the introduction, consisting of an alloy containing residual iron (Fe), and ancillary elements and impurities, and having a hardness of at least 230 HB formed through cold deformation.

The advantages obtained by the present invention include in particular the synergistic effects of the material properties which can be achieved through cold deformation in such chemical compositions and resistance to chemical corrosion of the selected alloy. At colder temperatures than the recrystallization temperature of the face-centered cubic austenite, the dislocation movement in the crystal lattice is hindered by cold deformation or deformation, thereby hardening the material. In combination with this, even at operating temperatures of 600 ° C. or higher, surprisingly, the hardness increase and strength increase of the material according to the invention are maintained, for example, such as thermally activated cross slip and recombination of dislocations, The expected recovery process in the distorted grating cannot be observed in the usual period. In other words, contrary to the expert opinion, the heat resistance of the material having the composition according to the invention, which is increased through cold deformation, is maintained even at the high service temperature of the part, because the high creep resistance of the steel improves the creep properties of the steel. Because it is. Particularly in the case of dynamic thermal loads, such as in molds for producing durable glass, severe temperature fluctuations occur at the working surfaces, respectively, and therefore local volume fluctuations of the material occur. Due to the increased material hardness and heat resistance according to the invention local or near surface deformation of a material, such as a glass mold, occurs within the elastic range of the material, which can therefore manifest itself in slight plastic deformation and breakage of the mold. It has been found that fatigue cracking, which can cause toxicants, is suppressed.

To ensure an improved property profile of the material, it is important that the material stays within a stable austenite region even upon cold deformation and does not have a region containing strain-induced martensite. This is achieved by nickel concentrations and chromium concentrations given within the limits according to the invention and by the concentration ranges of nickel given with limited chromium, silicon, manganese, nitrogen and carbon. As shown in the figure, higher nickel content deteriorates creep properties. On the other hand, a low nickel concentration drastically reduces the austenite stability and heat resistance of the material. Substantially the same applies to carbon and nitrogen, in which nitrogen in particular increases the creep resistance of the material.

The material is:

0.02 to 0.20 weight%, preferably 0.04 to 0.15 weight% of carbon (C),

0.50 to 2.48% by weight, preferably 1.22 to 2.36% by weight of silicon (Si),

0.62 to 4.05% by weight of manganese (Mn), preferably 1.00 to 3.95% by weight,

20.1 to 27.6 weight%, preferably 23.9 to 26.5 weight% of chromium (Cr),

16.1 to 27.3 weight%, preferably 17.9 to 25.45 weight% nickel (Ni),                         

The use properties of parts and tools according to the invention can be improved when they contain 0.014 to 0.23% by weight, preferably 0.018 to 0.20% by weight of one or more alloying elements of nitrogen (N). In this case, as is known, it has been found that even in the alloy according to the present invention, the heat resistance of the material can be improved when the content of cobalt is 0.52% by weight.

Although molybdenum, vanadium, tungsten, titanium and niobium increase the creep resistance of the material at high temperatures, and copper and aluminum represent typical hardening elements, these steel impurities contained within the material according to the invention It has a maximum allowable concentration because, as it has been confirmed, the higher the content of impurities in the steel, the lower the corrosion resistance, especially during temporary contact with glass in the form of dough, and the transparency of the glass due to the roughness of the mold surface. Because it is reduced. The cause for this is not yet fully understood, but the receptor atoms Na ⁺ , K ⁺ , Ca ²⁺ , B ³⁺ , Al ³⁺ and Si ⁴⁺ are included in Lewis acid, and thus the respective free After molding, a load occurs due to high temperature corrosion of the mold.

Since impurities deteriorate the properties of the original material, the alloy according to the present invention is in the case of incidental elements and / or impurity elements,

Molybdenum (Mo) less than 1.0 wt%

Vanadium (V) 0.5 wt% or less

Tungsten (W) 0.5 wt% or less

Copper (Cu) 0.5 wt% or less                         

Cobalt (Co) 6.5 wt% or less

Titanium (Ti) 0.5 wt% or less

Aluminum (Al) 1.5 weight% or less

Niobium (Nb) 0.5 wt% or less

Oxygen (O) max 0.05 weight%

Phosphorus (P) max. 0.03 weight%

Sulfur (S) has a concentration value of up to 0.03% by weight.

The object of the present invention is achieved through a process for the production of materials for parts and tools, having high non-reactivity, in particular high oxidation resistance and increased hardness at thermal loads by temperatures up to 750 ° C., according to which the nickel of the alloy The content is equal to or equal to the value formed by "Chrome content + 1.5% by weight of silicon-0.12% by weight of manganese-18% by weight of nitrogen-30% by weight of carbon-6" or in some cases up to 4.8% by weight is greater (Ni ≥ Cr + 1.5). × Si-0.12 Mn-18 × N-30 × C-6), substantially

0.01 to 0.25 weight% carbon (C),

0.35 to 2.5 weight percent silicon (Si),

0.4 to 4.3 weight% manganese (Mn),

16.0 to 28.0 weight percent of chromium (Cr),

15.0 to 36.0 weight percent nickel (Ni),

A composition of nitrogen (N) of 0.01 to 0.29% by weight,

An initial product is produced from an alloy containing residual iron (Fe), and ancillary elements and impurities, which are then further processed to a material having a hardness greater than 230 HB through cold deformation.

By cold deformation of the alloy according to the invention, the elastic limit of the material can be raised to a stress level which is not reached even near the working surface of the part or tool during volume fluctuations due to alternating heat loads. Therefore, cracks due to metal fatigue can be prevented because no plastic deformation region occurs even within the grain boundary region during temperature fluctuations. As a result, grain boundary erosion due to chemical corrosion or high temperature corrosion can be sufficiently prevented. As a result, the quality of the working surface or the quality of the surface is kept high for a long time even when the load is large and the production volume is large, such as in the case of glass molding. In contrast, conventional glass molding often exhibits material erosion with a spacing in the range of several microns at grain boundaries even after a short use time. As a result, roughness in the visible range is imparted to the molded glass, whereby reflective interference and frosted glass effects can occur.

If a material having a hardness greater than 250 HB, in particular more than 300 HB, is formed by cold deformation according to the method of the invention, the corrosion resistance and heat resistance can be further increased and fatigue cracks can be effectively suppressed.

When an initial product having a composition according to the invention is produced by hot working and subjected to a solution treatment or forcibly cooling from the processing temperature and optionally cold deformation, the initial product has an improved corrosion resistance, in particular tissue Homogeneous materials can be produced.

In particular, tools generally formed axisymmetrically, such as water bottle molds and similar molds, may be advantageous in that the cold deformation of the material is carried out over its entire circumference in a radial direction perpendicular to the longitudinal axis of the initial product.

To improve the quality of the product, the following alloying elements, namely

Carbon (C) = 0.02 to 0.20 weight%, preferably 0.04 to 0.15 weight%

Silicon (Si) = 0.05 to 2.48 weight%, preferably 1.22 to 2.36 weight%

Manganese (Mn) = 0.62 to 4.05 weight%, preferably 1.00 to 3.95 weight%

Chromium (Cr) = 20.1 to 27.6 weight%, preferably 23.9 to 26.5 weight%

Nickel (Ni) = 16.1 to 27.3 weight%, preferably 17.9 to 25.45 weight%

Nitrogen (N) = 0.014 to 0.23% by weight, preferably an alloy containing at least one alloying element of 0.018 to 0.2% by weight is produced.

Finally, another object of the present invention is that the nickel content of the alloy is equal to, or in some cases, the value formed from "chromium content + 1.5 silicon weight%-0.12 manganese weight%-18 nitrogen weight%-30 carbon weight%-6". Up to 4.8 weight% is greater (Ni ≥ Cr + 1.5 × Si-0.12 Mn-18 × N-30 × C-6),

0.25 wt% or less carbon (C),

Silicon (Si) up to 2.5% by weight,

Manganese (Mn) up to 4.3% by weight,

16.0 to 28.0 weight percent of chromium (Cr),                         

15.0 to 36.0 weight percent nickel (Ni),

Achieved by using an iron-based alloy containing 0.01 to 0.29% by weight of nitrogen (N) as an alloying element, and containing residual iron (Fe) and incidental elements and impurities, the alloy being more than 555 ° C. A material for heat treatment tools having a high working temperature, preferably higher than 602 ° C., in particular a working temperature below 750 ° C., through cold deformation of the initial product produced from the materials, at least 230 HB, preferably 250 HB. Strengthen to greater material hardness.

In view of the quality and economic production of the product, it is highly desirable that the aforementioned iron-based alloys are used as tool materials in the glass industry, in particular as molding tools for mechanical press glass.

The material according to the invention is explained in more detail by comparison of the test results.

1 shows the strength according to the degree of cold deformation of the material according to the invention at an inspection temperature of 604 ° C. The test material was forged at a temperature of 1010 ° C., forcedly cooled from the processing temperature, and subjected to a solution solution at 1060 ° C. Tensile specimens were produced therefrom after cold deformation was performed at material rates of 21%, 35%, 47% and 55% for the material portions, respectively. The determination of strength (value), more precisely the determination of yield point and tensile strength of 0.2%, was made at a temperature of 604 ° C., with the test specimen being held at this temperature for 20 minutes. For comparison, the reference material was solvated at 1060 ° C., and test specimens prepared therefrom were also examined at 604 ° C. The bar graph of FIG. 1 clearly shows the increase in the material strength value with the degree of deformation, and there has already been a significant increase in strength (not shown in the graph) already at cold strains above 6%, in particular higher than 12%. .

In Fig. 2, the creep resistance of the material according to the invention is measured at 600 ° C through a hardness test in a state where the test piece is cooled, and compared with a material according to DIN (material number 1.2083 and material number 1.4028).

The material according to the invention is 0.08 wt% carbon (C), 1.7 wt% silicon (Si), 1.15 wt% manganese (Mn), 0.01 wt% phosphorus (P), 0.002 wt% sulfur (S) , 24.8 weight% chromium (Cr), 19.8 weight% nickel (Ni), 0.02 weight% nitrogen (N), 0.26 weight% molybdenum (Mo), 0.09 weight% vanadium (V), 0.11 weight% Tungsten (W), 0.12 wt% copper (Cu), 0.4 wt% cobalt (Co), 0.01 wt% titanium (Ti), 0.02 wt% aluminum (Al), 0.001 wt% niobium (Nb), It was dissolved in a composition of 0.0029% by weight of oxygen (O) and injected into the experimental ingot, which was hot deformed into the test material. The test material was subjected to a solution treatment at 1060 ° C., followed by quenching in water, and then the test piece indicated by the reference “H 5” was not deformed, and the test piece indicated by the reference “H 525” was 35%. The cold deformation of the film resulted in a long solution solution step at 600 ° C. Comparative materials 1.2083 and 1.4028 were cured in oil from 1020 ° C., annealed at 630 ° C. and solvated for a long time as well. After 45 hours, 90 hours, 140 hours and 180 hours had elapsed, the test material was discharged from the furnace and cooled, and the material was reinserted into the furnace after the material hardness test was conducted (thermal stress was varied). Comparative material "H 5" shows the expected behavior of hardness, whereas material "H 525" according to the invention, which is 35% cold strained, shows an increased hardness and high creep behavior of 315 HB. At 600 ° C., even with alternating heat load fluctuations, no decrease in material hardness and creep occurred. In comparison, the martensitic standard steel showed a pronounced decrease in hardness with the continued solution solution.

Through the present invention, materials having a hardness higher than 230 HB and having high creep resistance and improved creep properties and similar corrosion strength even at temperatures above 600 ° C., and improved in high hardness and increased corrosion resistance A method for economically manufacturing materials for parts and tools having use characteristics can be provided.

Claims (14)

As a material with high non-reactivity, high oxidation resistance and increased hardness at temperatures up to 750 ° C., the nickel content of the material alloy is "chromium content + 1.5 silicon weight%-0.12 manganese weight%-18 nitrogen weight%-30 carbon weight More than the value formed by%-6 "(Ni ≥ Cr + 1.5 × Si-0.12 × Mn-18 × N-30 × C-6), 0.01 to 0.25 weight% carbon (C), 0.35 to 2.5 weight percent silicon (Si), 0.4 to 4.3 weight% manganese (Mn), 16.0 to 28.0 weight percent of chromium (Cr), 15.0 to 36.0 weight percent nickel (Ni), A composition of nitrogen (N) of 0.01 to 0.29% by weight, A material having high non-reactivity, high oxidation resistance and high high temperature hardness, consisting of an alloy containing residual iron (Fe), and ancillary elements and impurities, and having a hardness of 230 HB or more by cold deformation. The material of claim 1 having high non-reactivity, high oxidation resistance and high temperature hardness with a hardness higher than 250 HB. 2. The material of claim 1 wherein the nickel content of the alloy is higher by 4.8 wt% or less than the value obtained according to the equation. The method of claim 1, 0.02 to 0.20% by weight of carbon (C), 0.50 to 2.48 weight% of silicon (Si), 0.62 to 4.05 weight% manganese (Mn), 20.1 to 27.6 weight percent of chromium (Cr), 16.1 to 27.3 weight percent nickel (Ni), A material having high non-reactivity, high oxidation resistance and high high temperature hardness, containing 0.014 to 0.23% by weight of nitrogen (N), at least one alloying element. The method according to any one of claims 1 to 4, Molybdenum (Mo) less than 1.0 wt% Vanadium (V) 0.5 wt% or less Tungsten (W) 0.5 wt% or less Copper (Cu) 0.5 wt% or less Cobalt (Co) 6.5 wt% or less Titanium (Ti) 0.5 wt% or less Aluminum (Al) 1.5 weight% or less Niobium (Nb) 0.5 wt% or less Oxygen (O) max 0.05 weight% Phosphorus (P) max. 0.03 weight% Sulfur (S) A material having high non-reactivity, high oxidation resistance and high high temperature hardness, comprising at least one additional element or impurity element having a concentration value of up to 0.03% by weight. A process for the manufacture of parts and tool materials having high non-reactivity, high oxidation resistance and increased hardness at thermal loads up to 750 ° C., wherein the nickel content is " chromium content + 1.5 silicon weight%-0.12 manganese weight%-18 Nitrogen weight%-30 carbon weight%-6 "or more (Ni ≥ Cr + 1.5 × Si-0.12 × Mn-18 × N-30 × C-6), 0.01 to 0.25 weight% carbon (C), 0.35 to 2.5 weight percent silicon (Si), 0.4 to 4.3 weight% manganese (Mn), 16.0 to 28.0 weight percent of chromium (Cr), 15.0 to 36.0 weight percent nickel (Ni), A composition of nitrogen (N) of 0.01 to 0.29% by weight, The initial product is produced from an alloy containing residual iron (Fe), and ancillary elements and impurities, and has a high non-reactivity, high oxidation resistance and high temperature hardness that cold-deforms the initial product to have a hardness greater than 230 HB. Method for producing the material having. 7. The material of claim 6, wherein the initial product is hot worked and subsequently processed by one or more of solution treatment and cooling from processing temperature to produce a material having high reactivity, high oxidation resistance and high temperature hardness. Manufacturing method. 7. A method according to claim 6, wherein the cold deformation is carried out in a radial direction perpendicular to the longitudinal axis of the initial product. 8. The method of claim 7, wherein the cold deformation is performed in a radial direction perpendicular to the longitudinal axis of the initial product. 7. A method according to claim 6, wherein the nickel content of the alloy is higher by 4.8 wt% or less than the value obtained according to the equation, having a high non-reactivity, high oxidation resistance and high temperature hardness. The alloy of claim 6, wherein the alloy is 0.02 to 0.20% by weight of carbon (C), 0.50 to 2.48 weight% of silicon (Si), 0.62 to 4.05 weight% manganese (Mn), 20.1 to 27.6 weight percent of chromium (Cr), 16.1 to 27.3 weight percent nickel (Ni), A process for producing a material having high reactivity, high oxidation resistance and high high temperature hardness, containing 0.014 to 0.23% by weight of nitrogen (N), at least one alloying element. The process for producing a material according to claim 6, wherein the cold deformation produces a material with a hardness higher than 250 HB. The nickel content of the alloy is obtained by "chromium content + 1.5 silicon weight%-0.12 manganese weight%-18 nitrogen weight%-30 carbon weight%-6" (Ni ≥ Cr + 1.5 × Si-0.12 Mn-18 × N Greater than or equal to 4.8% by weight 0.25 wt% or less carbon (C), Silicon (Si) up to 2.5% by weight, Manganese (Mn) up to 4.3% by weight, 16.0 to 28.0 weight percent of chromium (Cr), 15.0 to 36.0 weight percent nickel (Ni), Contains 0.01 to 0.29% by weight of nitrogen (N) as an alloying element, contains residual iron (Fe), and incidental elements and impurities; An alloy for heat treatment tools used as a material for heat treatment tools at working temperatures higher than 555 ° C., an iron-based alloy that is strengthened to a material hardness greater than at least 230 HB through cold deformation of the initial product produced from the elements. . The alloy for heat treatment tools according to claim 13, which is used as a material for iron-based heat treatment tools used as a tool material in the glass industry.

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