JPS5933776B2 - stainless steel wire rope - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a stainless steel wire rope, particularly a wire rope made of high-silicon-containing stainless steel as a wire. The wire rope has a self-lubricating function.

One field where wire ropes are applied is the driving force transmission mechanism in precision machinery, and as a means of transmission.
A small diameter stainless steel wire rope with an outer diameter of less than m is applied and installed.

Such stainless steel wire ropes are required to have corrosion resistance and reliable mechanical properties, but conventional stainless steel wire ropes of this type have a problem in that they cannot be said to fully meet the above requirements.

Attach the wire rope to the driving force transmission mechanism as a belt,
When this operation is repeated, tensile stress acts on the wire rope, and bending stress occurs in the portion where the wire rope is wound around the pulley, drum, etc.

In addition, deformation called Hertzian stress occurs in this bent portion.

This appears as a phenomenon in which the wire rope deforms to fit the groove shape of the pulley and the flat winding surface of the drum.
It is known that this deformation appears strongly in proportion to the number of strands.

Due to this phenomenon, pressure contact stress acts between the strands constituting the wire rope, causing wear between the strands due to repeated operation of the wire rope.

In this worn area, fine particles that appear to be metal oxides are observed to be generated.

This is a phenomenon called fretting corrosion.

When this phenomenon is observed, it is determined that wear has occurred between the strands and fatigue of the wire rope is progressing.

Therefore, it is recognized that preventing the occurrence of the fretting corrosion phenomenon is an effective means for preventing wire rope fatigue.

Conventionally, as a means to prevent the occurrence of the fretting corrosion phenomenon and prevent fatigue of the wire rope, wire ropes are coated with a synthetic resin film such as nylon 12 or braided with the same synthetic resin, and a Measures such as impregnating the wire rope with lubricating oil, and applying a soft metal having a lubricating function to the strands of the wire rope have been implemented.

However, according to such conventional means, in addition to the process of forming the wire rope, it is necessary to add another process for imparting a lubricating function to the wire rope before and after the process, which increases the number of man-hours and materials. There is a problem that this increases, leading to a decrease in manufacturing efficiency and an increase in costs.Moreover, the lubricating function is lost due to the deterioration and disappearance of the lubricating oil and the lubricating means provided to the wafer. There was a problem.

Therefore, this invention applies heat treatment and cross processing to high-silicon-containing stainless steel to form strands made of fine crystal grains, and constructs a wire rope with these strands, thereby creating a self-containing structure between the strands. It has a lubrication function and solves the problems of the conventional method.

That is, an object of the present invention is to constantly self-lubricate between the strands by using the fine crystal grains forming the strands without using a separate lubrication means, The purpose of the present invention is to continuously maintain the wear resistance of the wire rope by the lubrication function, and further, it is an object of the present invention to eliminate the need for a separate lubrication means by the self-lubrication function.
The aim is to improve the manufacturing efficiency and reduce costs of wire rope.

Next, this invention will be explained.

The strands are made of high silicon-containing stainless steel.

High silicon content stainless steel is stainless steel containing about 3.5 to 6% silicon, which is different from conventional stainless steel,
For example, compared to SUS 304, which contains 0.9%, the content is about 4 to 6.7 times higher.

In addition, this high silicon content stainless steel also has 0.0 carbon
It contains appropriate components such as 8% or less, manganese or less, 5% or less of chromium, and 6 to 20% of chromium, and is configured to suppress toughness so as to enable heat treatment and cold working.

If the workability of high silicon-containing stainless steel is increased by suppressing its toughness, the wear resistance will decrease, so heat treatment and cold working are repeated on the stainless steel. When forming a steel wire, the crystal grains are made finer, thereby increasing the toughness of the stainless steel.

That is, the high silicon-containing stainless steel with suppressed toughness and improved workability is rolled into a wire rod, and heat treatment and cold wire drawing are repeated by known means to refine the crystal grains of the stainless steel. The toughness of the stainless steel is strengthened and the wire is drawn to a predetermined diameter.

The heat treatment is preferably bright annealing.

This means that silicon is fluorine at room temperature and chlorine at 430℃.
This is because various reactions are likely to occur, such as oxygen at 400°C and bromine at 500°C.

This heat treatment may be either low temperature annealing or solution annealing.

Thus, the high silicon-containing stainless steel wire with enhanced toughness and finer grains has a slippery surface.

The strands thus obtained are twisted to form a strand of a predetermined diameter, and a predetermined number of strands are further twisted to form a wire rope of a predetermined diameter.

Here, since the surface of the wire is slippery as described above,
A self-lubricating function acts between the strands of wire rope,
Wear between the strands is extremely reduced.

Therefore, even if Hertzian stress occurs in the wire rope, the fretting corrosion phenomenon hardly occurs, and the wear resistance is high.

As is clear from the above, according to the present invention, due to the toughness of the strands and the smoothness of the surface, it is possible to obtain a wire rope that has both toughness and wear resistance based on the self-lubricating function. .

Since the toughness and wear resistance are functions resulting from the characteristics of the wire itself, these characteristics can be maintained at all times while the wire rope is in use, and no separate lubrication means are required.

Therefore, there is an effect that the process and cost of adding a separate lubrication means can be reduced.

(Example) High silicon-containing stainless steel has component values shown in Attached Table 1.

(Attachment 1) Composition list of high silicon content stainless steel (%) After rolling the high silicon content stainless steel into a wire rod of 0.7 mrnφ, heat treatment is performed using the same method as the wire drawing process of 5TJS304 stainless steel. By repeating the cold wire drawing process, the wire was drawn to 0.08+o++φ to obtain a wire.

Seven of these strands were twisted together to form a strand, and these seven strands were twisted together to form a stainless steel wire rope having a configuration of 7×7 and a rope diameter of 0.72 mm.

The breaking strength of this wire rope was 47.7 kgf.

Using this wire rope, set the rope strength efficiency,
The number of bending cycles until breakage was determined by a repeated bending fatigue test.

The rope strength efficiency is denoted by η and is based on the following formula.

The high silicon-containing stainless steel wire rope and S
The results of the repeated bending fatigue test with US 304 stainless steel wire rope are shown in Attached Table 2 and Figure 1.

Both wire ropes have strands of 0.08 myφ and configuration 7.
×7, the rope diameter is 0.72 mm.

In Fig. 1, the solid line indicates the high silicon content stainless steel wire rope, and the two solid lines indicate the upper and lower limits.

Furthermore, the broken line indicates 5US304 stainless steel wire rope.

Further, the mechanical properties of the high silicon content stainless steel wire rope are shown in the graph of FIG.

Thus, even if the rope strength efficiency was low, the fatigue life of the stainless steel wire rope of the present invention was long.

Furthermore, the fretting corrosion phenomenon is extremely low, and while the SUS 304 stainless steel wire rope has a reddish tinge, the stainless steel wire rope of the present invention has a whitish tinge.

In addition, by repeating heat treatment and cold working on high silicon-containing stainless steel having the component values shown in Attached Table 1, the base material of high silicon-containing stainless steel with refined crystal grains as described above was prepared using the Ito method. SUS'304L was tested using a wear test machine.
Attached Table 3 shows the results of a wear test with stainless steel.

This also confirmed that high silicon-containing stainless steel has extremely high wear resistance.

According to the above examples, by repeating heat treatment and cold working, the grain refinement of high silicon-containing stainless steel is promoted, and the toughness as a so-called two-phase alloy is exhibited, and the strands of strands are It can be seen that the surface becomes slippery and the wire rope has a self-lubricating function, thereby imparting wear resistance to the wire rope.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the fatigue curve of the example of the present invention, and FIG. 2 is a graph showing the mechanical properties of the example of the present invention.

Claims (1)

[Claims] 1 High silicon content stainless steel is heat treated and cold worked to refine the crystal grains, and the resulting wires are twisted together.
A stainless steel wire rope characterized by a self-lubricating function between the strands.