JP5992402B2 - Manufacturing method of nitrided sintered component - Google Patents

Description

  The present invention relates to a method for producing a sintered element by a single press and a single sintering and to a sintered component produced by this method. This method provides a cost-effective production of sintered steel components that have a wear resistance comparable to components made from chilled cast iron.

  In the industry, the use of metal products made by compacting and sintering metal powder compositions is becoming increasingly popular. A large number of different products with different shapes and thicknesses are manufactured, and the required quality is constantly increasing, while at the same time reducing the price. Net shape or near net shape components, which require minimal machining to reach the final shape, are obtained through the use of advanced materials and pressing and sintering of iron-based powder components. There are significant advantages over the prior art of forming metal parts such as forming from bar or machining, casting or forging.

  There is a desire to increase the performance of sintered parts and to replace more parts with this cost-effective technology. Steel components in various industries, such as the automotive industry, have been successfully manufactured by pressing and sintering techniques. Automobile parts are manufactured in large quantities for applications where strict requirements for performance, design and durability are established. Thus, single press and single sintering techniques are very suitable for manufacturing such parts if the overall quality requirements are met.

  Certain transmission and valve mechanism components in the automotive industry, such as cam lobes, have excessive wear resistance requirements and are very difficult to switch to products sintered using conventional methods. . Today, the main manufacturing technology for such components is machining from bar or casting with chilled cast iron (CCI). In the case of small automotive cam lobes with somewhat lower requirements on wear resistance, parts have been successfully manufactured using double press / double sintering. However, at present, manufacturing techniques involving single press and single sintering have not proven to provide wear characteristics comparable to components manufactured using CCI.

  WO 2006/0455000 is produced from an iron-based powder metal mixture consisting of 0.5-3.0% Mo, 1-6.5% Cr, 1-5% V and Fe and the balance of impurities. The present invention relates to a carburized sintered alloy used for cam lobes and other high wear articles. However, its wear resistance has not reached the same level as the CCI element.

  Surprisingly, the use of certain iron-based powder alloy compositions in combination with warm die compaction and short nitriding processes provides wear resistance comparable to components made with CCI. It has been found that it is possible to produce components with properties.

More specifically, this involves the following steps:
a) of less than 0.3% by weight of Mn, 0.2 to 3.5% by weight of Cr, 0.05 to 1.20% by weight of Mo and 0.05 to 0.4% by weight of V Providing a pre-alloyed iron-based steel powder comprising at least one and up to 0.5% by weight of incidental impurities, the balance being iron;
b) mixing the pre-alloyed iron-base steel powder with a lubricant and graphite, optionally with a machining enhancing agent and other conventional sintering additives;
c) compression-molding the mixed composition of step b at a pressure of 400 to 2000 MPa to provide a molded body,
d) sintering the shaped body from step c at a temperature of 1000-1400 ° C. in a reducing atmosphere to provide a sintered component;
e) nitriding and sintering the sintered component of step d under a nitrogen-containing atmosphere at a temperature of 400-600 ° C. with a soaking time of less than 3 hours;
It can be achieved by a method of manufacturing a sintered component by single press and single sintering, including the steps.

  Components produced by this method exhibit wear resistance properties similar to CCI components. The component has a hard case with a soft core and is therefore not fully cured. A fully hardened component makes assembly more difficult than a case hardened component case with a soft core.

  This method is particularly suitable for automotive components operating in an oil-lubricated environment where the operating temperature is below 250 ° C. and the component has a role of relying on sliding motion. For example, cam lobes, sprockets, CVTs, other transmission mechanisms, valve mechanisms, engine components, and the like. Of course, the method is also suitable for producing components for other applications where good wear properties are required.

Manufacture of iron-based alloyed steel powder The pre-alloyed iron-base steel powder provided in step a of the method is preferably manufactured by water-melting iron melt containing alloying elements. Is done. The spray powder is further subjected to a reduction annealing process. The particle diameter of the pre-alloy powder alloy may be any size as long as it can coexist with the pressing and sintering processes. Examples of common particle sizes are those of the known powder ASC 100.29 available from Hoganas AB, Sweden, ie up to 2.0% by weight above 180 μm and 15-30% below 45 μm % Is the particle size. However, it is possible to use a coarser and finer granular powder.

  In the field of powder metallurgy, the use of coarse iron-based steel powder is becoming increasingly popular. Examples of such powders are iron-base steel powders having an average particle size between 75 μm and 300 μm, with less than 10% of the powder particles having a size below 45 μm and the amount of particles above 212 μm Is over 20%.

  Finer iron-base steel powder can also be used. When using fine powders, the fine powders are preferably combined with binder (s) and / or flow agent (s) to provide better powder properties and compressibility. Such powders can have an average particle size in the range of 20-60 μm, for example.

Prealloy steel powder content The prealloy steel powder provided in step a of the above method is based on iron and comprises Mn and at least one selected from the group of Cr, Mo, V It is. The prealloy steel powder may optionally further include Ni and / or additional strong nitrides that form elements (singular and plural) such as tungsten, titanium, niobium and / or aluminum. Good.

  Manganese (Mn) is present in an amount between 0.02 wt% and 0.3 wt%. In particular, if the prescribed treatment for reduction during the steel production process is not carried out, it is extremely difficult to achieve a content of less than 0.02% by weight when using recycled scrap, which increases costs. Furthermore, manganese increases the strength, hardness, hardenability of the steel powder, and therefore preferably has a manganese content greater than 0.05% by weight, and ores greater than 0.9% by weight. A Mn content greater than 0.3% by weight increases the formation of manganese, including inclusions in the steel powder, and also has a negative effect on the compressibility due to solid solution hardening, increasing the ferrite hardness. Therefore, the Mn content should not exceed 0.3% by weight. The most preferable range of Mn is 0.1 to 0.3% by weight.

  Chromium (Cr) as an alloying element plays a role of strengthening the matrix by solid solution hardening. Chromium also increases the curability and wear resistance of the sintered body. Furthermore, Cr is a very strong nitride formation and therefore promotes nitridation. When added, the chromium is at least 0.2 wt%, preferably at least 0.4 wt%, more preferably at least 1.3 wt% so that it has the desired effect on the properties of the sintered component. Should be added in the amount of. However, as the chromium addition increases, the requirement for a controlled atmosphere during sintering increases and the cost for manufacturing the components increases. Therefore, if chromium is added, it should be at most 3.5 wt%, preferably at most 3.2 wt%. In a preferred embodiment, the chromium content is 0.4-2.0% by weight, more preferably 1.3-1.9% by weight. In another preferred embodiment, the chromium content is 2.8-3.2% by weight.

  Molybdenum (Mo) stabilizes the sintered ferrite. If molybdenum is added, it should be added in an amount of at least 0.1 wt%, preferably at least 0.15 wt% so as to have the desired effect on the properties of the sintered component. If the Mo content is too high, it will not contribute sufficiently to the performance, which is undesirable. Therefore, when molybdenum is added, the molybdenum should be at most 1.2% by weight, preferably at most 0.6% by weight. In some embodiments, the steel may be essentially Mo-free, having a Mo content below 0.1% by weight, preferably below 0.05% by weight.

  Vanadium (V) increases strength by precipitation hardening. Vanadium is also a powerful nitride-forming element, with a grain size refining effect. When vanadium is added, the vanadium is at least 0.05 wt%, preferably at least 0.1 wt%, more preferably at least 0.25 wt% so as to have the desired effect on the properties of the sintered component. Should be added in the amount of. However, a high vanadium content facilitates oxygen supplementation, thereby increasing the oxygen level in the component produced by the powder, but an excessive amount is undesirable. The vanadium content should therefore be at most 0.4% by weight, preferably at most 0.35% by weight.

  The prealloy steel powder is optionally further known as additional strong nitride forming element (s), such as tungsten (W), titanium (Ti), niobium (Nb), aluminum (Al). One or more elements selected from the group may be included. When added, the total amount of the element (s) forming the additional strong nitride is between 0.05% and 0.5% by weight, preferably 0.1% and 0%. .4% by weight, more preferably between 0.15% and 0.30% by weight.

  Nickel (Ni) increases strength and hardness while providing good ductility properties. However, nickel is an expensive element and should be avoided as much as possible. When added, the content is kept low. The pre-alloyed steel powder may optionally contain 0.1 to 1.0 wt% Ni, preferably 0.1 to 0.5 wt% Ni. In a preferred embodiment, the prealloy steel powder is essentially free of nickel and therefore contains less than 0.1% by weight, preferably less than 0.05% by weight of nickel.

  Oxygen (O) is at most 0.25% by weight. A high oxygen content impairs the strength of the sintered component and reduces the compressibility of the powder. For these reasons, O is preferably at most 0.18% by weight. In practice, it is difficult to achieve an oxygen content below 0.1% by weight when using water spray technology. Therefore, the oxygen content in the water sprayed and annealed powder is usually in the range of 0.10 to 0.18% by weight.

  Carbon (C) in the steel powder should be at most 0.1% by weight, preferably less than 0.05% by weight, more preferably less than 0.02% by weight, and nitrogen (N) is much more However, it should be 0.1% by weight, preferably less than 0.05% by weight, more preferably less than 0.02% by weight. Higher carbon and nitrogen contents lower the powder compressibility unacceptably.

  The amount of each accompanying impurity element, such as an element selected from the group consisting of copper (Cu), phosphorus (P), silicon (Si), sulfur (S), and other elements unintentionally added to the alloy, Less than 0.15% by weight, preferably less than 0.10% by weight, more preferably less than 0.05% by weight so as not to deteriorate the compressibility of the steel powder or act as a harmful inclusion formation Most preferably, it should be less than 0.03% by weight. The total amount of all incidental impurities should be less than 0.5 wt%, preferably less than 0.3 wt%, more preferably less than 0.2 wt%.

Preferred embodiments of prealloyed steel powder In a preferred embodiment, the prealloyed steel powder according to the present invention comprises:
The remaining Fe,
0.09 wt% to 0.3 wt% Mn,
1.3 wt% to 1.9 wt% Cr;
0-0.3 wt% Mo,
It consists of up to 0.3% by weight of incidental impurities.

In another preferred embodiment, the prealloy steel powder according to the invention comprises
The remaining Fe,
0.09 wt% to 0.3 wt% Mn,
1.3 wt% to 1.6 wt% Cr,
0.15-0.3 wt% Mo,
It consists of up to 0.3% by weight of incidental impurities.

In yet another preferred embodiment, the prealloy steel powder according to the invention comprises
The remaining Fe,
0.09 wt% to 0.3 wt% Mn,
1.5 wt% to 1.9 wt% Cr;
0-0.1 wt% Mo,
It consists of up to 0.3% by weight of incidental impurities.

In yet another preferred embodiment, the prealloy steel powder according to the invention comprises
The remaining Fe,
0.09 wt% to 0.3 wt% Mn,
2.8 wt% to 3.2 wt% Cr,
0.4 to 0.6% by weight of Mo,
It consists of up to 0.3% by weight of incidental impurities.

In yet another preferred embodiment, the prealloy steel powder according to the invention comprises
The remaining Fe,
0.09 wt% to 0.3 wt% Mn,
0.05 wt% to 0.4 wt% V;
0-0.1 wt% Mo,
It consists of up to 0.3% by weight of incidental impurities.

Before powder composition compression molding, prealloyed steel powder, the lubricant, graphite, optionally with one or more machining enhancers (singular and plural), and optionally other conventional additives, for example, hard phase material (hard phase material).

  Carbon is introduced into the matrix to increase the strength and altitude of the sintered component. Carbon is added to the composition as graphite in an amount between 0.15 and 1.0% by weight of the composition. If the amount is less than 0.15% by weight, the strength becomes too low, and if it exceeds 1.0% by weight, excessive carbides are formed, which negatively affects the characteristics of nitride formation. Preferably, the graphite is added in an amount between 0.20 and 0.80 wt%, more preferably 0.30 to 0.60 wt%.

  A lubricant is added to the composition to facilitate compression molding and extrusion of the compression molded component. Addition of less than 0.05% by weight of the lubricant composition has no significant effect, and additions of more than 2% by weight of the composition will result in too low a density of the compacted body. Preferably, the amount of lubricant added is between 0.3 and 0.8% by weight of the composition, more preferably between 0.4 and 0.6% by weight of the composition. . Any type of lubricant suitable for compression molding may be used. The lubricant may be selected from the group of metal stearates, waxes, fatty acids and derivatives thereof, oligomers, polymers, and other organic substances having a lubricating effect.

In one embodiment, composite lubricating particles suitable for compression molding with a heated die, eg, 10-60% by weight of at least one primary having more than 18 and no more than 24 carbon atoms. A composite lubricant particle comprising a core of a primary fatty acid amide and 40 to 90% by weight of at least one fatty acid bisamide, wherein the lubricant particles are deposited on the core. Are also selected that also contain the nanoparticles.

In a preferred embodiment, the composite lubricating particles suitable for compression molding with a heated mold comprise 10-30% by weight of at least one primary fatty acid amide and 70-90% by weight of at least one fatty acid. And bisamide. The at least one fatty acid bisamide is preferably selected from the group consisting of methylene bis oleamide, methylene bis stearamide, ethylene bis oleamide, hexylene bis stearamide, and ethylene bis stearamide. The at least one metal oxide nanoparticle is preferably selected from the group consisting of TiO ₂ , Al ₂ O ₃ , SnO ₂ , SiO ₂ , CeO ₂ and indium titanium oxide.

  Copper (Cu) is generally used by alloying elements in powder metallurgy technology. Cu increases strength and hardness through solid solution hardening. Cu also facilitates the formation of a sintering neck during sintering as copper melt before the sintering temperature is achieved, providing so-called liquid phase sintering. The powder may optionally be mixed with Cu, preferably 0.2 to 3 wt% Cu. In a preferred embodiment, copper is not mixed into the composition.

  Nickel (Ni) increases strength and hardness while providing good ductility properties. However, a content exceeding 1.5% by weight tends to form Ni-rich austenite during the heat treatment conditions, thereby reducing the strength of the material. The powder may optionally be mixed with Ni in an amount of 0.1 to 1.5% by weight. In a preferred embodiment, nickel is not mixed into the composition.

Machining enhancer (s) can optionally be mixed into the composition in an amount of 0.1 to 1.0% by weight of the composition. Below 0.1% by weight, the effect is inadequate, and above 1.0% by weight, no further improvement is brought about. Preferably, when mixed, the machining enhancer (s) is 0.2-0.8% by weight of the composition, more preferably 0.3-0.7% by weight of the composition. is there. The machining enhancer (s) are preferably from the group consisting of MnS, MoS ₂ , CaF ₂ , and / or phyllosilicates such as kaolinite, smectite, bentonite, and mica (such as moscobite or phlogobite). Selected. In operating conditions, the machining enhancer (s) also act as solid lubricants and therefore help to increase the wear resistance of the composition. Other conventional sintering additives, such as hard phase materials, may optionally be mixed into the composition.

The compression-molded iron-based powder composition is transferred to press molding and subjected to a molding pressure of 400 to 2000 MPa, preferably 500 to 1200 MPa. In a preferred embodiment, the mold in the press is heated at a temperature of 40-100 ° C, preferably 50-80 ° C, before and during compression molding. This technique is referred to as “warm mold compression molding” or “heated die compaction”. Preferably, the component is at least 7.10 g / cm ^3, preferably compression molded at least 7.15 g / cm ^3, more preferably the green density of at least 7.20 g / cm ^3.

  Thanks to the choice of lubrication and compression molding process, a high green density can be achieved, ensuring a high sintered density without excessive dimensional changes. This provides good tolerances and closed pores of the sintered component.

The green component obtained by sintering is further subjected to sintering in a reducing atmosphere at a temperature of about 1000-1400 ° C. In a preferred embodiment, the component is sintered at a standard sintering temperature in the range of 1000 to 1200 ° C, preferably 1050 to 1180 ° C, and most preferably 1080 to 1160 ° C. However, depending on the requirements, the component can also be sintered at higher temperatures, for example 1200-1400 ° C, preferably 1200-1300 ° C, most preferably 1220-1280 ° C.

The component is sintered to a density in the range of 7.1-7.6 g / cm ³ , preferably 7.15-7.50 g / cm ³ , more preferably 7.20-7.45 g / cm ^3. . However, it is also possible to sinter to a density higher than 7.6 g / cm ³ .

The treated sintered component after sintering is then subjected to a nitriding step to obtain the desired microstructure. The nitriding step is performed in a nitrogen-containing atmosphere at a temperature around 500 ° C. In a preferred embodiment, the nitriding step is performed at a temperature of 400-600 ° C., preferably 470 ° C.-580 ° C., with a soaking time of less than 3 hours, preferably less than 2 hours, more preferably less than 1 hour, and nitrogen and hydrogen gas. In a mixture of However, the soaking time during nitriding is preferably at least 10 minutes, more preferably 20 minutes.

    Optionally, other commonly found types of nitriding processes can be used, for example (but not limited to) carbonitriding, nitrocarburizing.

    Excessive nitrogen penetration into a component can lead to a brittle structure, so when sintering a component with gas nitriding, the sintered component usually closes the pores and allows for adjustment of nitrogen penetration In order to do that, it needs to be steamed first. However, this step is not essential when providing the component according to the invention, since the sintered density achieved is high enough to ensure closed pores. Thus, the component can be nitrided in a coordinated manner without the previous step of steaming.

    When using the method of the present invention, the surface of the component has a thickness of 1-20 μm, preferably 5-15 μm, a nitrogen-rich so-called white layer or compound layer, and a nitrogen enriched, approximately 1-6 mm. And preferably a curing zone up to a depth of 1 to 4 mm.

Properties of the final component The component produced according to the present invention achieves high wear resistance in lubricated sliding contact. The abrasion resistance achieved is comparable to components made from chilled cast iron.

  Sintered components have closed pores directly after sintering without the need for steam treatment prior to gas nitriding.

  Furthermore, components made by the claimed method contain deeper surface pores compared to CCI components, which means that lubricants and machining enhancers will be present in these pores In the condition, it seems to provide a lubricating effect without being tied to any specific theory.

In a preferred embodiment, the final nitrided component is 0.5 to 1 mm deep and more than twice the core, preferably more than 600 MHV _0.05 , more preferably 700 MHV when the core hardness is 300 MHV _{0.05. When} the core hardness is more than _0.05 or 700 MHV _0.05 and the core hardness is around 350 MHV _0.05 , it preferably has a hardness of more than 800 MHV _0.05 . The depth of all cases should be between 0.5-4 mm, preferably 1.0-3.0 mm, more preferably 1.5-2.5 mm.

  The term core hardness should be understood as the hardness value at the center of the component before nitriding. The term full case depth should be taken as the distance from the surface of the component, where the hardness value is the same as its core hardness value.

  According to the test method described in the Examples section, the final component demonstrates good wear resistance in lubricated sliding contact. When tested at a sliding speed of 2.5 m / s in 100 seconds, the component exhibits safe wear against Hertz pressures of up to at least 800 MPa, preferably up to at least 900 MPa, more preferably up to at least 1000 MPa.

Test Methods General characterization of wear in lubricated sliding contact was performed by researchers at international levels participating in the informal group IRG-WOEM backed by OECD in the 1980s. Several collaborative studies have given the significance of the beneficial outcome that the IRG-wear transitions diagram can be the most important (see Figure 1).

  The IRG wear transition diagram (FIG. 1) shows three main wear areas: mild (safe) wear, marginal wear, and wear (critical adhesion wear). This wear depends mainly on the relative sliding velocity between the contact surfaces, but other factors such as lubrication, lubricant properties, surface roughness, ie contact body. It also depends on topography, surface metallurgy, and surface geometry. Different alloys show similar curves under different pressures, and FIG. 1 is only shown as an example.

  An automotive cam lobe for cam follower sliding contact is a good example of a component subjected to a sliding speed of about 0.1 m / s and in use over 3 m / s. In 1988, Chatterley [T. C. Chatterley, “Cam and Cam Follower Reliability”, SAE Paper No. 885033, 1988] have compiled a test bench for the MIRA engine that tests many chilled cast iron (CCI) cam lobes against CCI coated, boronized and ceramic followers. The 1000 MPa level passed only the CCI for the SiN ceramic test combination, while the 800 MPa Hertz level was unfailing for most of the test run.

  Based on the above, this was done using standard engine oil (see Table 1 of the specification) at 90 ° C. as a lubricant at three sliding speeds, ie 0.1, 0.5 and 2.5 m / s. A wear test in the survey was conducted. At 2.5 m / s, tests were conducted in stages with increasing Hertz pressure until wear occurred.

  A wear test was performed using a commercially available tribometer, a multipurpose friction and wear measuring machine, along with a crossed cylinders test setup (FIG. 2). While the AC thyristor control motor drives the counter ring, the tribometer applies a working load to the cylinder specimen holder by dead weight / load arm. This counter ring has the option of being immersed in an oil bath with about 25 ml of oil and heated to 150 ° C. The PC controls this test and records the linear displacement, wear, friction force and oil temperature at the contacts. The displacement transducer is placed on the load arm lever, not on the test cylinder, so the linear displacement obtained exceeds the wear track and is linear wear. About three times. Hertz pressure is proportional to the linear wear h of the cylinder sample, which in turn is proportional to the wear scar length a. As shown by FIG. 3, this length a can be visually determined using an optical microscope.

Table 1 lists the properties of the lubricating oil used during the wear test.

Table 2 lists the prealloy steel powders used during the test.

  Distaloy (TM) DC-1, Astaro (TM) CrL and Astaloy (TM) 85Mo are known powder metallurgy prealloy steel powders available from Hoganas AB (www.hoganas.com). Powder C is produced in the same way as Astloy ™ 85Mo and Astloy ™ CrL.

  As summarized in Tables 3 and 4, the test samples for this study were a sintered test sample and a reference cast iron sample.

  FIG. 4 represents the results from the evaluation of the test sample at 2.5 m / s. Surprisingly, it can be seen that all samples made according to the invention have reached levels comparable to the reference samples R1 and R2, ie the reference example of chilled cast iron. Comparing the CR of the reference sample with the C-A, C-B, and C-C of the present invention, how efficient is the new method of manufacturing a sintered component by single press / single sintering? It becomes clear.

  Furthermore, the composition C-A was compared before and after the three nitridation steps. The results can be seen in Table 5.

  In Table 5, it can be seen that the nitriding step is essential to the material properties. Already at the hertz level of 320 MPa, the components that were only subjected to the claimed steps a) to d) and not the nitriding step e) showed significant wear. On the other hand, the components subjected to steps a) to e) showed significant wear for the first time at a hertz level of 1100 MPa. That is, it improved significantly. The results in Table 5 are illustrated in FIG.

  FIG. 6 shows a metallographic image of the nitride sample C-A. As shown by the above results, a white nitride enriched layer with high adhesion wear resistance is found on the sintered surface.

FIG. 7 shows the hardness analysis results of sample C-A measured with Vickers (according to ISO 4498: 2005 and ISO 4507: 2000). As can be seen in this figure, the hardness was about 700 MHV _0.05 at a depth of 1 mm, thus forming a case with a hardness higher than twice the hardness of the center.

Claims (12)

A method of manufacturing a nitrided sintered component by single press , single sintering and nitriding , comprising:
a) and less than 0.3 mass% Mn, of 0.2 to 3.5 mass% Cr, the 0.05 to 1.20 mass% Mo and 0.05 to 0.4 mass% of at least one of a and V, the steps of providing 0.5 and mass% of incidental impurities up, comprising a balance of iron, pre-alloyed iron-based steel powder,
b) mixing the pre-alloyed iron-based steel powder with a lubricant and graphite, optionally mixing with a machining enhancer and other conventional sintering additives;
c) subjecting the mixed composition of step b to compression molding at a pressure of 400 to 2000 MPa using a mold heated to 40 to 100 ° C. to provide a molded body;
d) sintering the shaped body from step c at a temperature of 1000-1400 ° C. in a reducing atmosphere to provide a sintered component;
e) nitriding the sintered component of step d under a nitrogen gas-containing atmosphere at a temperature of 400-600 ° C. for a soaking time of less than 3 hours;
Hints, the lubricant is 10 to 60 mass%, 18 at least one primary fatty acid amide having 24 or fewer carbon atoms in excess, and 40-90 mass% of at least one fatty acid bisamide A composite lubricating particle comprising a core of the at least one metal oxide, wherein the lubricating particle also comprises at least one metal oxide nanoparticle deposited on the core.   The method of claim 1, wherein the shaped body is not steamed prior to nitriding in step e. The method according to claim 1 or 2, wherein in the step c, the shaped body is compression-molded to a green density of at least 7.10 g / cm ³ . The method according to claim 1 or 2, wherein in step d, the sintered component is sintered to a density between 7.1 and 7.6 g / cm ³ . The prealloyed iron-based steel powder further containing Ni between 0.1 and 1.0 mass%, A method according to any one of claims 1 to 4.   The method according to any one of claims 1 to 4, wherein the pre-alloyed iron-base steel powder is essentially free of Ni. The prealloyed iron-based steel powder, tungsten (W), titanium (Ti), niobium (Nb), between aluminum 0.05 to 0.50 mass% one or more elements selected from the group of (Al) The method according to claim 1, further comprising: The pre-alloy iron base steel powder is
The remaining Fe,
And Mn of less than 0.09 mass% to 0.3 mass%,
1.3 and Cr in mass% to 1.6 mass%,
0.15 to 0.3 and the mass% of Mo,
0.3 and the mass percent of the incidental impurities in the maximum,
The method according to claim 1, comprising: The pre-alloy iron base steel powder is
The remaining Fe,
And Mn of less than 0.09 mass% to 0.3 mass%,
1.5 and Cr of mass% to 1.9 mass%,
0.1 and mass% of Mo at the maximum,
0.3 and the mass percent of the incidental impurities in the maximum,
The method according to claim 1, comprising:   During a lubricated sliding contact that provides safe wear against Hertz pressures of at least up to 800 MPa when tested at a sliding speed of 2.5 m / s for 100 seconds by the method according to claim 1. A method of manufacturing the nitrided sintered component having wear resistance at:   During a lubricated sliding contact that provides safe wear against Hertz pressures up to at least 900 MPa when tested at a sliding speed of 2.5 m / s for 100 seconds by the method according to claim 1. A method of manufacturing the nitrided sintered component having wear resistance at:   During a lubricated sliding contact that provides safe wear against Hertz pressures of at least 1000 MPa when tested at a sliding speed of 2.5 m / s for 100 seconds by the method according to claim 1. A method of manufacturing the nitrided sintered component having wear resistance at: