JPH02298233A - Wear-resistance sheave material - Google Patents

Abstract

PURPOSE:To drastically reduce the wear loss in a sheave and a wire rope to be brought into contact with the sheave by using cast iron having specified compsn. as a sheave material and forming an oxidized film essentially constituted of Fe2O3 and having lubricity on the surface of the sheave. CONSTITUTION:The molten metal of cast iron having the compsn. constituted of, by weight, 3.0 to 4.0% C, 0.4 to 2.6% Si, <0.5% Mn, <0.4% Mo, 0.1 to 1.5% Ni, <0.1% Cu, <0.1% Cr, <0.1% Al and the balance Fe is poured into a mold to cast into a sheave. The sheave is subjected to normalizing treatment to form an oxidized film essentially constituted of Fe2O3 on the surface. Moreover, a graphite structure to form a lubricant is precipitated and 240 to 360 HB Brinell hardness is regulated as the material. The hardness of the sheave and a wire rope hanging therefrom approaches and the wear of the sheave and the wire rope is both reduced, by which the durability of the sheave can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a wear-resistant sheave material, and in particular to a wear-resistant sheave material that reduces wear and extends the life of both suspended wire lobes and the sheave itself. The present invention relates to a wear-resistant sheave material that can improve traction performance as well as improve traction performance.

(Prior art) Civil engineering for elevators and crane trucks that lift people and cargo in high-rise buildings! The equipment is equipped with a small hoisting equipment with wire lobes suspended from sheaves.

This equipment is constructed so that a wire lobe is wrapped around a sheave, a cage containing people or cargo is connected to one end of the wire lobe, and the cage is raised and lowered by the frictional force between the wire lobe and the sheave.

Conventionally, sheave materials for this type of lifting equipment have been Japanese Industrial Standards (JIS) standard materials (such as C20 and Fe1).
Flake graphite cast iron such as 2 or FCD45 or FC
Spheroidal graphite cast iron such as D70 is generally employed. The characteristics required of these sheave materials include not only sufficient yield strength, toughness, and fatigue strength to support the moving load of the elevator, but also the strength, toughness, and fatigue strength required for both the wire rope and sheave to facilitate maintenance management. It is required that the wear m is sufficiently small.

(Problems to be Solved by the Invention) However, the above-mentioned conventional material is cast iron whose matrix structure is a mixed structure of ferrite structure and pearlite structure or a medium structure, and the hardness of the structure is 1
8 is about 150-280.

On the other hand, the hardness (HB) of the wire rope suspended on the sheave made of the above-mentioned conventional material generally has a high value of 430 to 470, so when the two members come into sliding contact, the soft sheave will unilaterally move due to relative slip. It wears out and has a short lifespan.
There were problems with maintenance management, such as the need for frequent replacement.

In order to solve this problem, measures have been taken to heat-treat the sheave material to increase its hardness and prolong its life.

However, when the hardness of the sheave material is increased, the amount of wear on the wire lobes increases, and the service life of the lobes ends prematurely.

Furthermore, if the hardness of the sheave material is increased excessively, the suspended wire rope will easily slip within the sheave groove, resulting in a decrease in traction performance, which will shorten the life of the wire rope and sheave, and in some cases is 2-3
There was a problem in that frequent replacement was required every year, which resulted in a significant increase in maintenance and management costs.

The present invention was made to solve the above problems, and it reduces the amount of wear on both the wire rope and the sheave, extends the lifespan, facilitates maintenance management, and at the same time significantly improves the traction performance of the wire rope. The purpose is to provide a wear-resistant sheave material that can be improved.

[Structure of the invention]

(Means and effects for solving the 14 problems) In order to achieve the above object, the present inventors have conducted intensive experimental research on the mechanism of wear generation and the alloy composition and heat treatment conditions of sheave materials that can deal with the wear. As a result, we obtained the following findings.

In other words, the wear between the conventional sheave and wire rope is l
The process progresses under conditions where the Il/I lubricating oil film disappears, and in conventional sheaves, metal surface wear (bright surface wear) is predominant.

However, by changing the composition of the cast alloy to increase the oxidizability of the sheave material and producing an iron oxide film on the sheave surface, the oil film at the contact area between the wire rope and the sheave is caused by the razing effect of the oxide film. It has been found that even when the two parts disappear, the amount of wear on both members can be significantly reduced.

In addition, by setting the hardness of the sheave material to a predetermined range that is closer to the hardness of commonly used wire ropes, it is possible to reduce the abrasion of both the wire rope and the sheave. At the same time, it was found that mutual immersion was eliminated and sufficient traction performance of the wire rope could be ensured.

The present invention was completed based on the above findings. In other words, the wear-resistant sheave material according to the present invention contains carbon in a proportion of 3.0% to 4.0% and silicon in a proportion of 0.4%.
The content of 0.1% or less, and the remainder consists of iron and impurities contained in general cast iron materials.

In addition, the Brinell hardness HB of the sheave material is 240 or more and 360
J, (characterized by the following settings.

The present invention will be explained in detail below.

The present invention aims to reduce as much as possible the abrasion loss between the sheave and the wire rope due to their sliding contact, and particularly to improve the abrasion resistance of the sheave to the wire rope.

The characteristics aimed at by the present invention are obtained by injecting a molten alloy containing alloying elements in the above composition range into a mold, heat-treating the solidified metal, and forming an oxide film mainly composed of Fe2O3 on the surface of the sheave.・Also, it is obtained by forming a graphite structure that acts as a lubricant and further adjusting the hardness to a predetermined value.

Here, since the properties of spheroidal graphite cast iron are generally better than those of flaky graphite cast iron, the sieve material according to the present invention also uses a visiting material that forms a spheroidal graphite structure. In order to uniformly exhibit the lubricating effect of graphite and to equalize the wear on the sheave groove surface, and to avoid local wear, the graphite particle size must be made as small as possible and uniform in the matrix structure. It is necessary to disperse the

Furthermore, in the present invention, in order to improve wear resistance, the matrix structure of the sheave material is heat-treated to form a bainite structure, a single phase structure of ferrite or barley 1-, a mixed structure of both, or a martensitic structure, and its hardness is set to 240 or more and 360 or less on a Purinel hardness H8.

If the hardness H8) of the sheave material is less than 240, the wear of the sheave material will be noticeable, while if the hardness exceeds 360, the slippage between the sheave and the wire rope will increase, and the traction capacity of the wire rope will decrease. It will drop rapidly. Therefore, the above range is the hardness that provides an appropriate amount of wear between both members.

Further, it is desirable that the sheave material according to the present invention has good mechanical properties, particularly high tensile strength and good castability.

The purpose of adding each component and the reason for limiting the composition range will be explained below.

First, carbon (C) is added to increase the mechanical properties of the sheave material, especially the tensile strength, and if the content is less than 3.0%, the formation of graphite structure as a lubricant will fail. Enough is enough. On the other hand, if the content exceeds 4.0%, the tensile strength will decrease, so the content should be 3.0 to 4.0%.
Set to a range of 0%.

Next, silicon (S i ) is an essential element for forming a graphite structure together with carbon, and is also an element that improves castability. Formation is insufficient, resulting in reduced lubricity and poor castability, making casting defects such as shrinkage cavities more likely to occur.

On the other hand, if the content exceeds 2.6%, the hardness decreases and it becomes difficult to set the hardness (HB) to 240 or higher, so the content should be in the range of 0.4 to 2.6%. Set.

Manganese (Mn) is added to form a stable pearlite structure and improve strength and hardness, but if its content exceeds 0.5%, an oxide film of "e" will form on the surface of the sheave material. It becomes difficult to form lII, and the lII lubricity decreases.
It becomes difficult to adjust. Therefore, the manganese content is set to 0.5% or less.

Furthermore, molybdenum (Mo) is a bainite-promoting element, and has the effect of rapidly forming an oxide film on the surface of the material due to the catalytic effect of its oxide, and is added to improve wear resistance. However, if the content exceeds 0.4%, coarse carbides are formed, reducing machinability and increasing the wear layer of the wire rope that is the mating material. Therefore, its content is set to 0.4% or less.

Next, nickel (N1) contributes to homogenization and stabilization of the structure,
It is also attached to eliminate variations in hardness and to prevent the formation of oxides during heat treatment. but,
If the content is less than 0.1%, these effects will be small, while if it exceeds 1.5%, it will act in the direction of preventing the formation of an oxide film as a moisturizing agent, so the wear resistance will be reduced. It will drop. Therefore, the Ni content is 0.1 to 1
It is set within a range of 5%.

Further, copper (Cu) and chromium (Cr) are both elements that promote pearlitization and bainite formation, and aluminum (A1) has a function of improving corrosion resistance. However, the content m of any of the elements Cu, Cr and Aj
If it exceeds 0.1%, it becomes difficult to form an oxide film of Fe2O3, which has excellent lubricity, on the surface of the sheave, and the wear resistance deteriorates. Therefore, the contents of Cu, Cr and Aj are all set to 0.1% or less.

Note that the above-mentioned Cu, Cr, and AN are elements that are generally contained in trace amounts as impurities in casting raw materials, and are easily oxidized. In the present invention, Fe2 has particularly lubricating properties.
In order to preferentially form an oxide film mainly composed of O3,
The above Cu, Cr, A! J must not be contained in excess of the amount normally contained as an impurity, and must be kept at 0.1% or less.

In addition, in order to make graphite spheroidal, MO is added at a concentration of 0.03 to 0.
The content is preferably about 0.07%, preferably about 0.05%.

Heat treatment of the above composition material I! ! In this case, the temperature of the heat treatment must be such that the base tissue can be converted into Baini I-, and is preferably between about 850°C and 980°C, preferably 93°C.
Heating for about 60 to 120 minutes at 0℃ pre-heating ± 30℃ to form austenite 1F11, followed by heating at 300 to 400℃
After being immersed in a hot bath of salt or the like for 30 minutes to 3 hours, it is left to cool and is austempered to form a baini structure.

The material thus obtained has the above-mentioned Prinell hardness of H8240 to H360 and other properties, and is excellent in wear resistance and is particularly suitable as a sheave material for elevator sites.

(Example) An embodiment of the present invention will be described in more detail below.

Examples 1 to 4 A molten alloy having a composition not shown in Examples 1 to 4 in Table 1 was injected into a mold by a general sand casting method using a flan mold, and the results were as shown in Figures 1 and 2. I cast a wire [cope winding sheave 1] for an elevator as shown. This sheave 1 has a maximum outer diameter of 500 IM, the wall thickness of the sheave groove portion 2 in contact with the lobe material is about 40#, and the weight is about 30:9 cast iron.

All of the above cast iron castings are cast products having a spheroidal graphite structure.

[Margin below]

The cast iron casting of Example 1 is an as-cast material that is cooled and solidified by air cooling after pouring, and has a matrix structure having a mixed phase structure consisting of ferrite and pearlite, and a Brinell hardness of i,
1210-2301-18.

On the other hand, the cast iron casting of Example 2 was further subjected to standard treatment to form a normalized material. Here, the standard treatment is 9 for cast iron castings.
The mixture was heated to 00 to 930°C, held for 1 hour, and then cooled in air. As a result, the hardness was 2 with a pearlite cap of 11i oo%.
Obtained from 808B normalized material. Further, as Example 3, a sieve using the XJ method in Examples 1 and 2 was cast using a molten alloy having the composition shown in Table 1. Next, the 1q cast product was heated at 900 to 930°C for about 1 hour to form an austenitic structure, and then heated to 350 to 450°C of nitrate Il.
! ! The material was immersed in a salt bath furnace for 3 hours to undergo an austempering treatment in which it was allowed to cool, resulting in a bainite structure.

Brinell hardness H8 was 300.

Further, as Example 4, a molten alloy having the composition shown in Table 1 was used to cast a sheave having the same dimensions as Examples 1 and 2, and the resulting casting was further quenched and tempered.

The processing conditions were as follows: heated to 900-930°C, held for 1 hour, then quenched in oil at about 60°C;
After heating to 0 to 550°C and holding for 4 hours, it was allowed to cool and was tempered. As a result, the matrix was tempered multi + yite combination Jf*100% with a spheroidal graphite structure dispersed, and the hardness was 3.
A sieve of 60 was obtained.

The sheaves of Examples 1 to 4 thus prepared were mounted on a jγ abrasion tester, and a wire rope type A LJ was roughly attached to the sheave.
IS) A corresponding material was suspended and subjected to a rolling and sliding wear test, and the sheave groove wear depth 21 and lobe wear length ρ were measured, and the results shown in FIG. 3 were obtained.

Here, the wear test conditions were as follows: contact pressure was 10Kyf/~, grease was applied as lubricating oil by the initial filling amount, and sliding distance was set to 10Kyf/~.

On the other hand, as Comparative Examples 1 to 3, molten alloys having the compositions shown in Table 1 were used to cast sheaves with the same dimensions as those of Examples 1 to 4.The materials used were among the conventional materials. This is an FCC70 material that is said to have the highest wear resistance.All cast sheaves have a spheroidal graphite structure.

Comparative Example 1 is an as-cast material obtained by cooling after casting,
The matrix consisted of ferrite and 80% pearlite structure, and the hardness was 210 to 230 HB.

In Comparative Example 2, standard treatment was performed under the same heat treatment conditions as in Example 2, and the matrix consisted of 100% pearlite structure, and the hardness was 280H.

-Q was there.

Further, in Comparative Example 3, austempering treatment was performed under the same heat treatment conditions as in Example 3, and the structure was returned to "Baini", resulting in a hardness of 3001-18.

The sheaves of Comparative Examples 1 to 3 thus obtained were also subjected to wear tests under the same conditions as Examples 1 to 4, and the sheave groove wear depth a and lobe wear length 1 were measured, and the results are shown in Fig. 3. I got it.

In Comparative Examples 1 to 3, Examples 1 to 3 are as shown in Table 1.
Compared to No. 4, CLJ is contained in an excessive amount of 0.5%. CLJ is used in the alloying of general cast iron materials as a relatively inexpensive element that promotes the formation of pearlite Ill, but it also has the effect of increasing oxidation resistance. Therefore, if it is contained in the flow, the formation of an oxide film with high lubricity on the friction surface between the sheave groove and the wire lobe is inhibited. As a result, in Comparative Examples 1 to 3, the lubricity of the contact portion between the sheave and the lobe material deteriorates, and wear due to ablation wear and 'D' wear progresses rapidly, resulting in a shortened service life. In particular, it can be seen that the sheave of Comparative Example 1, which has a soft ferrite phase (hardness of 120 to 160) as a part of the matrix, shows significant abrasion and wear of the sheave groove is as large as 2.2 problems. .

In addition, c has the same effect as Cu to improve oxidation resistance.
When r and All were added in excessive amounts of 0.5% each, heat treatment was performed in the same manner as in Comparative Examples 1 to 3, and the wear characteristics were measured, and almost the same results as Comparative M1 to M3 were obtained. .

Further, in the sheave materials of Comparative Examples 1 to 3, no oxide film is formed at the interface between the wire lobe and the sheave groove, so the sheave full wear depth a is large. In the sheaves of Comparative Examples 2 and 3, in which the hardness of the sheave material was increased by heat treatment, the amount of wear of the wire lobes also increases rapidly, resulting in a shortened service life.

On the other hand, sheaves related to length overwhelming 1 to 4 are CLI, Cr, Aj
Since the content of metal elements that improve oxidation resistance such as is significantly reduced compared to the conventional examples shown in Comparative Examples 1 to 3.

Further, among Examples 1 to 4, the sieve of Example 1 in which a soft ferrite phase is formed as a part of the matrix is different from that of Examples 2 to 4.
Compared to No. 4, adhesive wear occurs slightly, so the amount of wear is relatively large and the structure is unstable.

Furthermore, the sheave of Example 4, which was subjected to quenching and tempering treatment, has extremely good wear characteristics, but there are some dimensional changes due to heat treatment, and the workability is lowered, so it was manufactured in comparison with the sheaves of Examples 2 and 3. tends to be somewhat difficult. Therefore, it has been found that sheave materials with a Brinell hardness of H8 of 360 or higher increase manufacturing costs and are disadvantageous in terms of light weight.

Although the examples have been explained using sheave materials for lifting elevators, the sheave materials of the present invention are not limited to such uses, and can be used for cast iron sheaves for other 8J heavy equipment, logistics machinery, construction machinery, etc. All 1fi21 used
It can also be effectively applied to i.

(Effects of the Invention) As is clear from the results of the Examples and Comparative Examples described above, the wear-resistant sheave material of the present invention not only reduces the amount of wear on the sheave itself compared to conventional materials. This also makes it possible to effectively reduce the amount of wear on the wire lobes suspended on the sheave, significantly extending the lifespan and simplifying the maintenance management of lifting equipment, etc. that uses the sheave.

[Brief explanation of the drawing]

FIG. 1 is a front view showing the shape of a sheave made of the wear-resistant sheave material according to the present invention, FIG. It is a graph showing the wear characteristics of the sheave material in comparison with a conventional example. 1... Sheave, 2... Sheave groove. Applicant's agent Hisakuchi Hatano □ Figure 1 Figure 2

Claims (1)

[Claims] 1. Carbon in a weight percentage of 3.0% to 400%, silicon in a range of 0.4% to 2.6%, and manganese as 0.5%.
% or less, molybdenum 0.4% or less, nickel 0.1% or less
% or more and 1.5% or less, and the content of copper, chromium, and aluminum is all 0.1% or less, and the remainder consists of iron and impurities contained in general cast iron materials. Wear-resistant sheave material. 2. The wear-resistant sheave material according to claim 1, wherein the Brinell hardness H_B is set to 240 or more and 360 or less.