JPS604901B2 - spinning ring - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a spinning ring in which a porous compound layer with voids is formed on the surface layer.

In a ring for a fine edge machine or a yarn twisting machine that makes a sliding pair, the traveler makes sliding contact with the ring while, for example,
Since it rotates at a high speed of 5,000 revolutions per minute to guide and twist the yarn, it is extremely important to minimize the friction between these two to ensure smooth traveler rotation in order to prevent yarn breakage. be.

Conventional rings are manufactured by applying nitriding or carburizing and quenching to surface steel, but the quenching hardness is low, the carburizing depth is shallow,
The manufacturing process was complicated, the cost was high, and the lifespan was short, so it was unsatisfactory.

It is an object of the present invention to solve the above-mentioned drawbacks and to provide a spinning ring that can be impregnated with oil and has high lubrication performance.

Therefore, in the present invention, an Fe-N compound layer is formed as a surface layer, a Fe-C-N martensitic layer is formed as an intermediate layer following this, and the layer near the surface has a large number of fine voids. This is a ring for spinning which has a porous compound layer formed thereon.

An embodiment of the present invention will be described below based on drawings (photographs).

The ring material is CO. This is a well-known steel material made of 15% by weight steel (SI&K), which is successively subjected to gas nitrocarburizing treatment and gas carburizing quenching treatment described below.

As a result, as shown in FIG. 1 (micrograph - sound of 3% nitric acid alcohol corrosion 40), the surface layer 1 is composed of a Fe-N compound (Fe3N, Fe4N, etc.) layer and a Fe-C compound (Fe3N, Fe4N, etc.) layer.
The thickness of the layer 1 is on the 0.03 side, and the layer 1 has high hardness, high quality, wear resistance, and exhibits a remarkable effect in improving galling resistance. The intermediate layer 2 is a retained austenite layer containing Fe-C-N martensite, and has a thickness of 0.2 to 0.25 mm. Since this layer contains nitrogen, it doubles the fatigue strength and has corrosion resistance. The lowermost layer 3 is made of a martensite layer containing almost no nitrogen. However, the surface layer 1
Figure 2 (sound microscopic enlarged microstructure photograph of 40 without corrosion)
As shown in the figure, the surface exhibits porosity with many voids formed on the surface.

This allows the ring to be impregnated with lubricating oil, thereby reducing frictional resistance with the traveler and increasing wear resistance. Here, the processing is performed by the following novel method.

That is, the SI or K material as the material to be treated is sealed in a gas nitrocarburizing furnace, and an endothermic shift furnace gas containing 50% NH3 gas and carbon monoxide as main components (consisting of 1 part butane to 10 parts air, Nitriding treatment A is carried out by heating within the range of 570° ±2000° for about 6 minutes as shown in the third figure in an atmosphere consisting of 50% (hereinafter referred to as RX). At this time, the following reaction occurs on the surface of the material, and carbon invades from the surface at the same time as nitrogen. Note that the mixing ratio is expressed as a volume ratio. NH3 gas 2NH32$L+2 [N] RX gas 2CO; C020 [C] Next, while the material is kept sealed in the furnace, the temperature is gradually raised from the above temperature (C process), The gas was gradually removed, and at the same time, the main component (about 99%) was RX gas, and then C4 days.

Gradually feed carburizing gas containing about 1% gas. and,
In 90 minutes from the start of temperature increase from 570 oo, the nitriding gas became almost zero, and the temperature reached about 820 oo with only carburizing gas remaining.
0.00, carburizing treatment B is performed for about 9 intervals in the fecal atmosphere, and then rapidly cooled and quenched. Soft nitriding treatment A
Since the nitriding and carburizing reactions are carried out even during the switching from the carburizing process B to the carburizing process C, the process efficiency is high and there is no heat loss. actually"
The compound layer obtained by gas nitrocarburizing and gas carburizing processes has few defects, and a surface is obtained in which a stable compound layer, nitriding diffusion layer, and carburizing layer overlap.

The concentrations of Fe, N, and C contained in each layer are as follows.

FIG. 7 shows the results of line analysis of the treated cross section using an x-ray microanalyzer. It can be seen that the outermost surface has a large amount of nitrogen, similar to the X-ray diffraction test results, and the inside has an increased amount of carbon, forming a carburized and hardened layer. In this way, in the composite heat treatment, two layers, a nitrogen compound layer and a carburized and quenched layer, are generated on the surface, resulting in a surface condition that cannot be obtained by conventional heat treatment methods. Furthermore, although the reason why many fine voids are formed near the surface is not clear, it can be clearly recognized in the micrograph shown in FIG. 2.

The coefficient of friction of the nitride layer with voids is low,
In addition, the initial wear makes it smooth and easily adapts to the traveler, so there is no need for break-in, and normal operation is possible immediately. Furthermore, the extremely hard carburized and quenched layer containing nitrogen at the bottom of the compound layer improves wear resistance, resulting in a lifespan of 1.2
~1. This has lengthened the period, contributing to improvements in the quality and operational efficiency of the paper process. The cross-sectional hardness distribution of the steel material subjected to the above treatment is shown in curve J (curve K for conventional rings) in Figure 4.
The hardness of the upper layer up to the 0.2 side is extremely high, and the thickness that satisfies the practical effective hardening hardness Hv513 as a ring is 0.3 ribs.

Furthermore, FIG. 5 is a comparison diagram of the frictional resistance index curve h of a ring subjected to the treatment method according to the present invention and a traveler, and the frictional resistance index curve i of a conventional ring over the course of the number of times the ring rail is raised and lowered. This proves that the ring treated according to the present invention has much better lubricity than the conventional ring by impregnating the voids in the surface layer with oil. The test conditions are as follows. ring
3.2 flange x 470 spun yarn
Cotton 40'S number of twists/p dimension
25.4 spindle rotation speed
Traveler using 14000R/M
OS510 lift 70 dimensions Furthermore, the following results were obtained as a result of tests under various usage conditions of a spinning machine using the ring of the present invention.

However, the lifts were all 7 inches. Figure 6 shows test curves of thread breakage index for rings of the present invention and conventional rings, respectively.

The ring of the present invention has a low and uniform friction coefficient due to the effect of the surface lubricating layer, and stable running conditions between the ring travelers are maintained. For this reason, as shown in FIG. 6, the number of thread breakages in each batch decreased from the time of startup until the full tube stop, and the total number of thread breakages decreased by approximately 30%. In particular, since there is a large reduction in thread breakage during startup, there is no need for break-in operation at the beginning of operation, and normal operation is immediately possible. In the test shown in Figure 6, the ring diameter was 440, the wire was 40S, the rotation speed was 1400 pm, and the traveler CS was 6/0.

Here, the conventional rings shown in FIGS. 4, 5, 6 and the table are made by carburizing low carbon steel (SI K). The gas for carburizing process is C4 in addition to RX gas.
Day,.

It may contain about 1% of NH3, or about 1 to 5% of NH3.
Further, the present invention is applicable to all carbon steels and alloy steels used for skin applications (CO.1 to 0.2%). As described above, the surface layer of the present invention contains a Fe-N compound, so it has excellent wear resistance, and the intermediate layer contains Fe-C-N martensite, so it has excellent corrosion resistance. Since it is porous with voids, it is possible to impregnate lubricating oil, which greatly reduces frictional resistance, reduces wear on the ring and traveler, extends life, and greatly reduces thread breakage, resulting in quality. It has the effect of significantly improving

[Brief explanation of the drawing]

Fig. 1 is a micrograph of the corroded surface of a spinning ring showing an embodiment of the present invention, Fig. 2 is a micrograph of the non-corroded surface layer, Fig. 3 is a manufacturing process diagram of the present invention, and Fig. 4 is Cross-sectional hardness distribution curve, Figure 5 is a friction resistance index curve diagram, Figure 6 is a thread breakage index curve diagram, Figure 7 is an element concentration distribution graph of a ring cross section.1.
...Surface layer, 2...Middle layer, 3...Bottom layer. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] 1 The surface layer constituting the traveler sliding surface is made of Fe-N and Fe-C compound layers, and the subsequent intermediate layer is made of Fe-N and Fe-C compounds.
-A ring for spinning in which a C-N martensitic layer is formed and a large number of fine voids are formed near the surface.