JPH05171366A - Martensite stainless steel body and method of producing same - Google Patents

Abstract

PURPOSE: To make it possible to produce a holding stand for metal mold and die excellent in strength, toughness, corrosion resistance and machinability, by producing it from a martensitic stainless steel having a specified compsn.

CONSTITUTION: The holding stand or the like for metal mold or die is produced from a martensitic stainless steel having a compsn. contg., by weight, <0.09% C and <0.09% N so as to regulate the total content of C+N to 0.02 to 0.09, <4.50% Mn, <0.05% P, 0.05 to 0.25% S, <1.0% Si, 1.00 to 4.00% Ni, 11.00 to 14.00% Cr, 0.25 to 1.00% Mo, <1.00% Cu, and the balance Fe, which is subjected to heat treatment at 816 to 955°C for about 1 hr per inch thickness to form its structure into austenitic one, heating and air-cooling or water-cooling to form martensitic structure and finally subjected to tempering treatment at a temp. between 260 and 455°C for 1 to 2 hr per inch. The holding stand having 30 to 40 Rockwell hardness and ≥100 drill cutting rate and excellent in corrosion resistance can be obtd.

COPYRIGHT: (C)1993,JPO

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to martensitic stainless steel objects used to hold fixed molds and dies and methods for making the same.

[0002]

Molds and dies used to manufacture parts made of materials such as plastics, during operation, are provided with frames, holders, supports and similar objects.
It is stuck in place. Generally, these bodies are made from steels of compositions that exhibit high strength and toughness, withstand the stresses associated with their use, and provide sufficient service life. Steel must also have good machinability, should facilitate the manufacture of these objects, and should be capable of being easily heat treated to the required hardness limit with a relatively large cut size.

Typical steels used in the manufacture of frames and holding pedestals are about 30 to 40 Rockwell C (Rockwell).
C) Hardened in advance within the hardness range of (HRC). This eliminates the need for heat treatment by the user and avoids the strain normally encountered in heat treating machined objects. A hardness range of 30 to 40 HRC is important, as at a hardness of about 40 HRC, the machinability of most steels becomes too expensive for the machining required for most uses. Lowering the hardness of the steel improves machinability, but at hardnesses below about 30 HRC, the steel lacks sufficient mechanical strength for these intended uses.

[0004] Like the sulfur-bearing modification of AISI 4140 and AISI 5150, low alloy carbon steels commonly used in the manufacture of holders have excellent mechanical properties in combination with good machinability. Offering a bond. However, they lack sufficient corrosion resistance and develop other types of rust and corrosion during use and storage.
This corrosion reduces operational safety, efficacy and service life, and also requires that the cradle and frame be covered with a protective coating when not in use.

Many corrosion resistant steels have been investigated in lieu of the common low-alloy carbon steels used in holding platform applications.
As disclosed in AISI Type 414, AISI Type 420, and US Pat. No. 3,720,545,
High grade stainless steel mold is considered. However, due to their price, nature, and relatively low machinability, they are not widely used for holding platform applications. AISI Type 420 and AISI Type 43 to overcome machinability issues
Zero sulfur-containing variants have been developed. Although these sulfur-containing steels have relatively good machinability, they are not well suited for this application. Wide hardness range of 30 to 40 HRC required for holding base, especially 35 to 40 H required for high strength holding base
This is because the inherent hardness and tempering properties make it difficult to manufacture them in the narrow hardness range of RC. In addition, the relatively high austenitizing temperatures used to harden these steels, typically 996 ° C (18
25 ° F. to 1038 ° C. (1900 ° F.) adds cost and imparts significant strain to the body during the hardening heat treatment. Further, at hardnesses in the range of about 30 to 40 HRC, these stainless steels characteristically have reduced toughness and corrosion resistance, significantly impairing their utility in their applications.

[0006]

The present invention is used for holding pedestals, frames, supporting pedestals and similar objects for holding molds and dies, and has improved strength, toughness, corrosion resistance and machinability. It is a primary object to provide a martensitic stainless steel object with a combination, and to provide a method for producing a martensitic stainless steel object having these properties by the use of simple hardening and tempering heat treatments. Has another related purpose.

[0007]

According to the invention, a martensitic stainless steel body having an improved combination of strength, toughness, corrosion resistance and machinability, produced by controlling carbon and nitrogen, and achieving the desired hardness. It is decided to get. Sulfur is controlled by carbon plus nitrogen and retains drill machinability at speeds of 100 or more (compared to commercially available stainless steel holding steels). For this purpose, sulfur must be increased with an increase in carbon and nitrogen content. Chromium and nickel are also present to maintain corrosion resistance. Molybdenum has also been added for corrosion resistance, especially to counteract the adverse effects of increased sulfur. Therefore molybdenum is increased with increasing sulfur content.

According to the invention, the martensitic stainless steel objects used for holding dies, frames, supports and similar objects for holding molds, dies according to the invention are compositions within the limits given in Table 1.

[0009]

[Table 1]

The body is characterized by a hardness in the range 30 to 40 HRC, preferably 3 for higher strength applications.
Hardness within the range of 5 to 40 HRC. By the method of the invention, the steels according to the compositional limits listed in Table 1 are
It is austenitized at a temperature in the range of 500 ° F. to 955 ° C. (1750 ° F.) for about 1 hour per 2.54 cm (inch) thickness and oil or air cooled to obtain a martensitic structure. The object is then at a temperature between 260 ° C (500 ° F) and 455 ° C (850 ° F) at a thickness of 2.54 cm.
Approximately 1 hour per inch and a minimum of 2 hours to reduce stress. After these heat treatments the body is 30 to 40 HRC, preferably 35 to 40 HRC for high strength applications.
It shows hardness within the RC range and drill machinability at speeds of 100 and above. Preferably, the object after tempering, when tested by the process disclosed below, has a size of 9 inches or less (2.
54 cm) / year.

[0011]

Detailed Description of the Preferred Embodiments Generally, stainless steel pedestals are made by hot rolling or forging an ingot into a slab or billet,
The slab, billet is subsequently heat treated to the desired final hardness, scaled to the desired shape and dimension and processed.
Rarely, the pedestal is cut from a fully annealed slab or billet, roughed, separately heat treated to the desired hardness and worked into its final shape. Generally, the hardness of standard holder applications is in the range of about 30 to 35 HRC, while the hardness of high strength holders is in the range of about 35 to 40 HRC.
In order to obtain these hardnesses at low cost and easily, the steel used for the holding table needs to be easily hot-processed to the required hardness. Common stainless steels currently used for corrosion resistant supports, such as the supports tested to obtain the data in Figure 1, in the range of about 30 to 40 HRC,
In particular, the tempering temperature required to produce hardness in the range of about 35 to 40 HRC is important, and a slight difference in temperature causes a large difference in hardness. Therefore, tight control of the tempering operation is required for these steels to obtain the hardness required for holding table applications. Furthermore, about 30 to 40 HRC
When tempered to hardness in the range, such steels exhibit relatively low notch toughness and corrosion resistance.

In comparison, it is possible with the holding base steel according to the invention, with a simple heat treatment, to obtain the improved combination of corrosion resistance, toughness and strength required for this application. Steel holders made according to the invention and steel holders within the composition limits given in Table 1 provide the desired hardness when hardened and tempered or stress-reduced at a wide range of temperatures. Is shown in FIG. For example, a steel retainer made from Heat V1056 containing 0.043% carbon plus nitrogen gave a hardness in the hardened state within the range required for a standard retainer (30- 35 HRC), and tempered at temperatures up to about 455 ° C. (850 ° F.) to obtain hardness within the required range when stress was reduced. Similarly, heat V1 with 0.079% carbon plus nitrogen
The pedestal made from 020, when hardened and tempered at a wide range of temperatures, reduced the stress to obtain the hardness within 35-40 HRC required for the high strength pedestal. Also about 996
Steel produced within the scope of the invention, in contrast to the type of stainless steel currently used for corrosion resistant support which is austenitized at temperatures between 1825 ° F (1825 ° F) and 1038 ° C (1900 ° F). Holding table is about 844 ℃
It can be austenitized from temperatures as low as (1550 ° F), resulting in considerable energy savings in heat treatment.

Regarding the chemical composition of the steels used in the holding pedestal of the present invention, in order to control their overall composition, they need to be within the composition ranges given in Table 1. The pedestal would then be substantially martensitic in the substantially cured state.
Austenite forming elements such as carbon, nitrogen, nickel and manganese to obtain a substantially complete martensitic structure in the cured state and ferrite forming elements such as chromium, molybdenum and silicon to minimize the formation of delta ferrite. The composition of the steel must be balanced. Large amounts of delta-ferrite are detrimental in steel in that they reduce the hardness and toughness of the holders made.

The hardness of the steel used in the inventive holding table in the hardened state is primarily a function of the carbon plus nitrogen content. In order to obtain the desired hardness in the 30-40 HRC range, it is necessary to control the carbon and nitrogen content within the ranges shown in Table 1. If the carbon plus nitrogen content is too low, the support will not have the minimum desired strength and hardness. If the carbon plus nitrogen content is too high, the holding table will exceed the desired maximum hardness and exhibit uncut machinability.

Manganese is the desired element in the steel used for the holder. Manganese provides hardenability and, in combination with sulfur, is present for the purpose of improving machinability through the formation of manganese sulfide. Manganese is also an austenite forming element and can be used in place of nickel in steel due in part to compositional equilibrium, thereby reducing the cost of the steel.

Silicon has been used in steelmaking to increase deoxidation and chromium recovery. It also improves the corrosion resistance slightly, but is a ferrite-forming element. It therefore increases the amount of expensive nickel or manganese needed to obtain a perfect martensitic structure.

In order to obtain the desired austenite-ferrite equilibrium, and thereby a substantially complete martensite structure, nickel in the range indicated on the holder is required. Nickel also improves corrosion resistance, but is an expensive element. Therefore, it is not desirable to exceed the range shown.

Chromium is essential for corrosion resistance, but austenite-forming elements increase the amount of nickel, manganese and other austenite-forming elements above the indicated amounts, avoiding the formation of delta-ferrite and substantially in the support. It is required to be present to obtain the complete martensite structure.

Molybdenum is an expensive alloying element, but in small amounts and with chromium, it has a favorable effect on the corrosion resistance of the holder. A minimum of about 0.25% is required to reduce the adverse effects of sulfur on this property. Therefore, molybdenum should generally be increased in the presence of increased sulfur.

Sulfur is used to improve machinability but reduces notch toughness and corrosion resistance. When high toughness and corrosion resistance are required on the inventive holding platform, sulfur is about 0.10.
Should be limited to%. However, when greater machinability is desired, it can be increased to about 0.25% without lowering toughness and corrosion resistance to unacceptable levels. To keep corrosion resistance at the desired level, molybdenum should be increased with increasing sulfur.

Steel is a common residual element in stainless steel melting and is used to control the austenite-ferrite equilibrium. However, above about 1.0%, it exhibits an undesired hardening effect during tempering of the holding table.

In order to demonstrate the essence of the invention, experimental holding base steels were made and subjected to various mechanical and corrosive tests. The chemical compositions of the experimental holding steel and the commercial stainless steel holding steel (alloy 90-45) included for comparison are shown in Table 2.

[0023]

[Table 2]

The experimental holding base steel ingot has about 117
Hot-worked into a stick from a reheat temperature of 7 ° C (2150 ° F). Samples were taken from the barbed for metallographic evaluation and testing. Except for the samples used to measure hardness, all samples were austenitized at 844 ° C (1550 ° F), air cooled to room temperature and 288 ° C (5 ° C).
Tempered at 50 ° F for 2 hours. After this heat treatment, none of the experimental holding steels contained delta ferrite. The commercially available stainless steel holding steel sample had a hardness of 33 HRC in the pre-hardened state. 38HR
To test this material at a higher hardness of C, a sample of a commercial holding base steel was austenitized at 1010 ° C (1850 ° F), oil cooled to room temperature, and 524 ° C (97 ° C).
Tempered at 5 ° F for 2 hours.

A test was conducted to compare the advantages of the inventive holding base steel to that of a commercial stainless steel holding base steel and to demonstrate the importance of its composition. The test is strength, notch toughness,
It is conducted to explain the effect of the steel composition on tensile strength, machinability and corrosion resistance.

The resulting hardness of the experimental holding steel in the hardened state is plotted in FIG. 3 as a function of carbon plus nitrogen content. Specimens for these tests were austenitized at 871 ° C (1600 ° F) for 15 minutes and air cooled to room temperature. Although there are normal variations in the hardness test results, FIG. 3 shows that the gall hardness of the steel used for the inventive carrier has a strong relationship with its carbon plus nitrogen content. In order to obtain the hardness (30-40 HRC) required for the holding base application, it is shown that the content of carbon plus nitrogen in the holding base of the invention should be controlled in the range between about 0.02 and 0.09%. ing. Further, in order to obtain the typical hardness of the standard holding base (30 to 35 HRC) and that of the high strength holding base (35 to 40 HRC), the carbon plus nitrogen content of the steel used for the holding base of the invention is about 0. It should be controlled from 02% to 0.06% and about 0.06% to 0.09%.

The results of the notch toughness and tensile tests performed on the experimental holding steel and the commercial stainless steel holding steel are shown in Table 3.

[0028]

[Table 3]

Char Pevie notch impact test (Char
The notch impact toughness of the steel used for the cradle of this invention, as measured by the py V-notch inpact test, is determined by the typical commercial stainless steel used in this application (alloy 90-4
These test results show that it is clearly superior to that of 5). The benefit in toughness is especially about 0.
Large for experimental steels containing less than 10% sulfur. It is the notch toughness value of alloy V1033 (4.23 kg-m or 30.
6ft-lb) of that of commercial stainless steel holding base steel (0.7kg-
m or 5.0 ft-lb). About 0.1
Above a sulfur content of 0%, the impact properties of the steel used for the inventive holding pedestals are still significantly better than those of the commercial stainless holding pedestals. For example, alloy V105 with 0.20% sulfur
The notch toughness of No. 5 is 2.07 kg-m (15.0 ft-lb) in the longitudinal direction.
However, that of the commercial stainless steel holding base steel (alloy 90-45) with 0.09% sulfur is only 0.69 kg-m (5.0
ft-lb) only.

The tensile properties of the steels used in the holding pedestals of the present invention are a function of their hardness and are at least comparable to those of commercially available stainless steel holding pedestals. Comparative steels with high nickel and low manganese (alloys V1020 and V
1056), the same mechanical properties and notch toughness have been obtained with high manganese and low nickel content laboratory holding base steels (alloys V1022 and V1055). Therefore, if cost is to be reduced, manganese can be used in place of the nickel used in the cradle of the present invention.

The results of the drill machinability tests performed on the commercial stainless steel holding base steel of the experimental steel used for the holding base of the invention are shown in Table 4 and FIG. The machinability index shown in this table and figure compares the time taken to drill holes of the same size and depth in the experimental steel and the commercial stainless steel holding base steel with a hardness of 33.0 HRC, Time ratio 1
It was obtained by multiplying by 00. An index of 100 or more indicates that the machinability of the test specimen is greater than that of the commercial holding base steel. Since it is known that the hardness and the sulfur content of these steels affect the machinability, parameters based on these factors [Rockwell C hardness-100 (%
S)] was derived and used to compare the drill machinability of test materials.

[0032]

[Table 4]

Analysis of drill machinability test data using the derived relationship between the above parameters and machinability index gives machinability at least equal to that of a commercially available stainless steel holding base steel with a hardness of 33 HRC. Therefore, it is shown that the steel used for the holder of this invention must contain at least 0.05% sulfur. Similarly, with a hardness of 33 HRC a cutting steel of the invention with a hardness of 38 HRC must contain at least 0.10% sulfur in order to obtain a machinability at least comparable to commercially available stainless steel holding base steel. In combination with the notch toughness test results shown in Table 3, these results show that at the sulfur levels between about 0.05% and 0.10%, the steel used for the inventive cradle was It has been shown to provide superior notch toughness and machinability over that provided by existing stainless steel holding bases. Also about 0.10% and 0.2
They show that, with a sulfur content of between 5%, the steel used for the holding table of the invention gives substantially better machinability and notch toughness than existing stainless holding table steels.

Two tests were used to compare the corrosion resistance of the steel used in the holders of this invention with that of a typical commercial stainless steel holder. Its composition is shown in Table 2.
In one test, the weight loss and the resulting corrosion rate were measured on specimens immersed in a diluted solution of aqua regia containing 5% nitric acid and 1% hydrochloric acid by volume for 3 hours at ambient temperature. This test is based on the literature (EA Oldfield, “Corrosion of Cutle
ry, "Corrosion Technology, June 1958, 187.
It is useful for comparing the effect of composition and heat treatment on the corrosion resistance of martensitic stainless steel. The term "corrosion rate inch (2.54 cm / year)" used here relates to the corrosion rate exhibited by the alloy body in this test process. These tests are
Passivated and non-passivated specimens in a solution of 20% nitric acid containing 3% by weight potassium chromate at 49 ° C. (12
0 ° F) for 0.5 hour. Another test was the salt spray test. In the spray test, the specimen was exposed to steam generated from an aqueous solution containing 2.5% by weight of salt at 32 ° C (90 ° C).
F) for 3 hours. In the latter test, material durability was visually aligned by assessing the% of surface area affected by corrosion. The results of the corrosion test are shown in Table 5. Figure 5 shows a photograph of 5 specimens from the salt spray test.
Is shown in.

[0035]

[Table 5]

The results of the diluted aqua regia and salt spray tests clearly show that the steel used for the cradle of this invention has substantially better corrosion resistance than the steel currently used for the stainless steel cradle. There is. This is alloy V1033 (4.3 inches (2.54 cm) / year) whose composition is within the scope of the invention.
And V1021 (5.5 inches (2.54 cm) / year) and alloy 90-45 (14.1 inches (2.54 cm) / year), which is a representative of the steels currently used for stainless steel holding pedestals. This is evidenced by the large difference in corrosion rates exhibited by water. Also, the great advantage of the steel used in the holder of this invention has been demonstrated in the salt spray test. It is evident in a comparison of the affected area percentages for these same alloys. Corrosion test results also demonstrate the importance of maintaining the molybdenum content of the steel used in the holding table of this invention above about 0.25%. In this regard, for example, alloy V with a composition within the scope of the invention, except for a very low molybdenum content.
Note the relatively low endurance of 1087 in comparison with the good endurance of alloys V1003 and V1009, which contain about 0.32% molybdenum and whose composition is within the scope of the invention.

Three experimental holding base steels (alloy V1009,
Comparative corrosion resistance of V1020 and V1020) and two steels outside the scope of the invention (alloys V1087 and 90-45) are further shown in FIG. As can be seen, alloys V1009, V1020, and V10 of compositions within the scope of the invention
No. 21 has considerably better corrosion resistance than the alloys V1087 and 90-45 in the salt spray test. The composition of alloy V1087 is similar to that of alloys V1009 and V1020, except that it contains less than 0.01% molybdenum.
Again, this demonstrates the importance of retaining a minimum of about 0.25% molybdenum in the steel used for the holder of this invention. Alloy 90-45 is representative of the steel currently used for stainless steel pedestals, and its relatively low durability again demonstrates that the steel used for the pedestal of the present invention has substantially good corrosion resistance. Cool

[0038]

The mechanical property test in Table 3 and Table 4
The results of the corrosion test along with the machinability test in Table 1 show that the corrosion resistant holding steel of the invention provides a superior combination of notch toughness, machinability and corrosion resistance substantially over the stainless steel holding bases in general. .. Furthermore, the steel used for the inventive holding table has the advantage that it can be hardened to the hardness required for this application with a simple heat treatment.

[Brief description of drawings]

Figure 1: 0.32% carbon by weight, 1.33% manganese,
0.32% Silicon, 0.097% Sulfur, 0.50% Nickel, 16.8% Chromium, 0.04% Molybdenum, 0.034%
FIG. 5 is a graph showing the relationship between tempering temperature and hardness of a holding base steel of a commercial stainless steel alloy 90-45 having compositions of nitrogen, residual iron and incidental impurities.

FIG. 2 is a graph showing the relationship between tempering temperature and hardness of two holding base steel alloys V1020 and V1056 according to the present invention.

FIG. 3 is a graph showing the relationship of carbon plus nitrogen content to the hardness of a support according to the invention in the cured state.

FIG. 4 is a graph showing the relationship between the drill machinability and sulfur content of an experimental holding base steel according to the invention with respect to parameters related to hardness.

5 (a) to (e) compare the corrosion resistance of two holding base steels having compositions outside the range of the invention and three holding base steels according to the invention in a 2.5% salt spray test (3 hours). It is a photograph of the metal structure that is in use.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Karl Jei. Dorsch, Pennsylvania, United States 15237 Pittsburgh Bonnet Drive 1537

Claims (29)

[Claims] 1. A holding table for holding a die and a die,
A frame, a martensitic stainless steel body that may be used in supports and similar bodies, the body having a hardness in the range of 30 to 40 Rockwell C, essentially 0.09% by weight. Up to carbon, up to 0.09% nitrogen, 0.0
2% to 0.09% carbon plus nitrogen, 4.50% manganese, 0.05% phosphorus, 0.05% to 0.25% sulfur, 1.0% silicon, 1. 00% to 4.00% nickel, 1.00% to 14.00% chromium, 0.25%
To 1.00% molybdenum, up to 1.00% copper, residual iron and incidental impurities, a martensitic stainless steel body. 2. A holding table for holding a die and a die,
A frame, a martensitic stainless steel body that may be used in supports and similar bodies, the body having a hardness in the range 35 to 40 Rockwell C, essentially 0.06% by weight. Up to carbon, up to 0.06% nitrogen, 0.0
2% to 0.06% carbon plus nitrogen, 2.00% manganese, 0.05% phosphorus, 0.05% to 0.25% sulfur, 1.00% silicon, 2. 00% to 4.00% nickel, 1.00% to 13.00% chromium, 0.25
A martensitic stainless steel object, characterized in that it comprises from% to 0.75% molybdenum, up to 1.0% copper, balance iron and incidental impurities. 3. An article according to claim 2 having 0.05% to 0.10% sulfur. 4. The object of claim 2 having 0.10% to 0.25% sulfur. 5. A holding table for holding a mold and a die,
A frame, a martensitic stainless steel body that may be used for supports and similar bodies, the body having a hardness in the range of 30 to 35 Rockwell C, essentially 0.06% by weight. Up to carbon, up to 0.06% nitrogen, 0.0
2% to 0.06% carbon plus nitrogen, 2.00% to 4.5
0% manganese, up to 0.05% phosphorus, 0.05% to 0.2
5% sulfur, up to 1.00% silicon, 1.00% to 2.
Characterized by: 00% nickel, 1.00% to 13.00% chromium, 0.25% to 0.75% molybdenum, 1.00% copper, residual iron and incidental impurities. Martensite stainless steel object. 6. The article of claim 5 having 0.05% to 0.10% sulfur. 7. The article of claim 5 having 0.10% to 0.25% sulfur. 8. A holding table for holding a mold and a die,
A frame, a martensitic stainless steel body that will be used for supports and similar bodies, the body having a hardness in the range of 35 to 40 Rockwell C, essentially 0.09% by weight. Up to carbon, up to 0.09% nitrogen, 0.0
6% to 0.09% carbon plus nitrogen, 2.00% manganese, 0.05% phosphorus, 0.05% to 0.25% sulfur, 1.00% silicon, 2. 00% to 4.00% nickel, 1.00% to 13.00% chromium, 0.25
A martensitic stainless steel body, characterized in that it comprises from% to 0.75% molybdenum, up to 1.00% copper, balance iron and incidental impurities. 9. The article of claim 8 having 0.05% to 0.10% sulfur. 10. The article of claim 8 having 0.10% to 0.25% sulfur. 11. A martensitic stainless steel object that may be used for holding pedestals, frames, supports and similar objects for holding molds and dies, wherein the object is 35.
To 40 Rockwell C, essentially by weight, carbon up to 0.09%, nitrogen up to 0.09%,
From 0.06% to 0.09% carbon plus nitrogen, from 2.00%
4.50% manganese, up to 0.05% phosphorus, from 0.05%
0.25% sulfur, 1.00% silicon, 1.00% to 2.00% nickel, 1.00% to 13.00% chromium, 0.25% to 0.75% molybdenum, A martensitic stainless steel body characterized by comprising up to 1.00% copper, balance iron and incidental impurities. 12. The object of claim 11 having 0.05% to 0.10% sulfur. 13. The article of claim 11 having 0.10% to 0.25% sulfur. 14. A method of making a martensitic stainless steel object that will be used for holding pedestals, frames, supports and similar objects for holding molds and dies, the method essentially comprising: % By weight, carbon up to 0.09%, nitrogen up to 0.09%, carbon plus nitrogen from 0.02% to 0.09%, manganese up to 4.50%, phosphorus up to 0.05%, 0.05% to 0.25% Sulfur, 1.0% Silicon, 1.00% to 4.00% Nickel, 1.00% to 14.00% Chromium, 0.25% to 1 Producing the body with an alloy composition of 0.000% molybdenum, up to 1.00% copper, balance iron, and incidental impurities, about 1 hour per inch of thickness from 816 ° C (1500 ° F) to 955 ° C (1750 ° C). °
F) austenitize the body at a temperature of F); then air or oil cool to a martensitic structure; then about 1 hour per inch of thickness and a minimum of 2 hours at 260 ° C (500 °).
F) to 455 ° C. (850 ° F.) to reduce stress by tempering to obtain a combination of hardness in the range of 30 to 40 Rockwell C and a drill machinability rate of 100 or more. Method for manufacturing site stainless steel objects. 15. The method of claim 14 wherein said alloy composition has 0.05% to 0.10% sulfur. 16. The method of claim 14 wherein said alloy composition has 0.10% to 0.25% sulfur. 17. The article, after the tempering, wherein the body exhibits a corrosion rate of less than or equal to 9 inches (2.54 cm) / year.
The method according to any one of 5 and 16. 18. A method of making a martensitic stainless steel body that will be used for holding pedestals, frames, supports and similar bodies for holding molds and dies, the method essentially comprising: % By weight, carbon up to 0.06%, nitrogen up to 0.06%, carbon plus nitrogen from 0.02% to 0.06%, manganese from 2.00% to 4.50%, 0.05
% Phosphorus, 0.05% to 0.25% sulfur, 1.00% silicon, 1.00% to 2.00% nickel, 11.1.
00% to 13.00% chromium, 0.25% to 0.75%
Made of an alloy composition of molybdenum, up to 1.00% copper, balance iron and incidental impurities; about 1 hour per inch of thickness from 816 ° C (1500 ° F) to 955 ° C (1
Austenitizing the body at a temperature of 750 ° F.) and then air or oil cooling to a martensitic structure, then about 1 hour per inch of thickness and a minimum of 2 hours at 260 ° C.
(500 ° F.) to 455 ° C. (850 ° F.) tempering the body to reduce stresses, combining hardness in the range of 30 to 40 Rockwell C and drill machinability rates equal to or greater than 100. A method for producing a martensitic steel object, which comprises: 19. The method of claim 18 wherein said alloy composition has 0.05% to 0.10% sulfur. 20. The method of claim 18, wherein the alloy composition has 0.10% to 0.25% sulfur. 21. After the tempering, the body exhibits a corrosion rate of 9 or less inches (2.54 cm) / year.
The method of any one of 9 or 20. 22. A method of making a martensitic stainless steel body that will be used for holding pedestals, frames, supports and similar bodies for holding molds and dies, the method essentially comprising: % By weight, carbon up to 0.09%, nitrogen up to 0.09%, carbon plus nitrogen from 0.06% to 0.09%, manganese up to 2.00%, phosphorus up to 0.05%. , 0.05% to 0.25% sulfur, 1.0% silicon, 2.00% to 4.00% nickel, 11.00% to 13.00% chromium, 0.25% to The body was made of an alloy composition of 0.75% molybdenum, up to 1.00% copper, balance iron and incidental impurities, and produced for approximately 1 hour per inch of thickness from 816 ° C (1500 ° F) to 955 ° C (1750 ° C). °
The material is austenitized at a temperature of F) and then air- or oil-cooled to obtain a martensitic structure, then about 1 hour per inch of thickness and a minimum of 2 hours at 260 ° C (500 ° C).
F) to 455 ° C (850 ° F) to temper the body to reduce stress and obtain a combination of hardness in the range of 30 to 40 Rockwell C and a drill machinability rate equal to or greater than 100. And a method of manufacturing a martensitic steel object. 23. The method of claim 22, wherein said alloy composition has 0.05% to 0.10% sulfur. 24. The method of claim 22 wherein said alloy composition has 0.10% to 0.25% sulfur. 25. After the tempering, the body exhibits a corrosion rate of 9 or less inches (2.54 cm) per year.
The method according to any one of 23 and 24. 26. A method of making a martensitic stainless steel object that will be used for holding pedestals, frames, supports and similar objects for holding molds and dies, the method essentially comprising: % By weight, carbon up to 0.09%, nitrogen up to 0.09%, carbon plus nitrogen from 0.06% to 0.09%, manganese from 2.00% to 4.50%, 0.05
% Phosphorus, 0.05% to 0.25% sulfur, 1.00% silicon, 1.00% to 2.00% nickel, 11.1.
00% to 13.00% chromium, 0.25% to 0.75%
Made of an alloy composition of molybdenum, up to 1.00% copper, balance iron and incidental impurities, and produced for about 1 hour per inch of thickness from 816 ° C (1500 ° F) to 955 ° C (1
Austenitizing the body at a temperature of 750 ° F.) and then air or oil cooling to obtain a martensitic structure, after which the body is about 1 hour per inch thick and a minimum of 2 hours, 2
30-40 Rockwell C by tempering at temperatures of 60 ° C (500 ° F) to 455 ° C (850 ° F) to reduce stress
A method for producing a martensitic stainless steel body, characterized by a combination of a hardness within the range and a drill machinability rate equal to or greater than 100. 27. The method of claim 26, wherein the alloy composition has 0.05% to 0.10% sulfur. 28. The method of claim 26, wherein the alloy composition has 0.10% to 0.25% sulfur. 29. After the tempering, the body exhibits a corrosion rate of 9 or less inches (2.54 cm) / year.
Or the method according to any one of 28.