JPS5933669B2 - Iron-chromium damping alloy with hardened surface layer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The damping alloy according to the present invention is carburized within 80% of the total surface area of the alloy member in order to increase wear resistance without impairing the vibration damping ability of the alloy. It is an iron-chromium vibration damping alloy with a surface hardening layer formed by metal plating, metal or ceramic spraying, or metal diffusion infiltration treatment.

In recent years, metallic materials with high vibration damping ability, such as ferrite-based domain wall displacement vibration damping alloys whose main alloy components are iron-chromium, have been used to help reduce noise and vibration generated from industrial machinery. However, the hardness of these alloys in practical use is approximately Hv150, making them unsuitable for applications requiring wear resistance. For this reason, it is necessary to take some measure to improve wear resistance. Although various surface hardening treatment methods have been put into practice as means for improving the wear resistance of metals, it is undesirable to sacrifice vibration damping ability.

From this point of view, when we conducted an experiment to investigate the effect of surface hardening on the vibration damping ability, we found that 80% of the total surface area of the alloy member
It was confirmed that if the surface hardening treatment is performed within the range below, the vibration damping ability does not decrease significantly. Based on the results of this experiment, the inventor filed a patent application for an iron-chromium magnetic domain wall displacement damping alloy member in which a hardened surface layer was formed within 80% of the total surface area of the alloy member through soft nitriding treatment. (Patent Application No. 117481/1981).

Thereafter, we conducted experiments to determine whether other methods could be used to form a hardened surface layer, and it was confirmed that surface hardening treatments such as carburizing, metal plating, metal or ceramic spraying, and metal diffusion penetration were effective. The above-mentioned metal diffusion infiltration treatment method is a treatment method in which a metal element is mainly diffused and coated, and the elements to be infiltrated include Cr, Si, B, Mo,
W, V, Be, Ti, Ta, Al, Zn, etc., and nitriding is not included.

The alloy composition of the damping alloy member according to the present invention is iron-chromium based, and specific examples thereof are as follows. (C) Basic components: C: 0.1% or less, Si: 4.5% or less, Mn: 3.
0% or less, Cr: 5-35%, Co: 30% or less, Al
: 8% or less (however, 51 and Al are used alone or in combination), residual Fe and impurities.

(2) Ingredients that promote the damping effect of alloy members consisting of the above components:
V: 0.05-3.0%, Mo: 0.05-5.0%,
Nb or/and Ta: one or more of 0.05 to 2.0% (total amount 0.05 to 6.0%)
.

(3) (C) or machinability improving components of alloy members consisting of (1) and (2): S: 0.05-0.20%, Pb: 0
．． 03-0.30%, Be: 0.03-0.20%, T
e: 0.01-0.20%, Bi: 0.03-0.30
%, Ca: one or more of 0.001 to 0.030%.

The reason for numerically limiting the alloying elements and their content in the alloy member of the present invention will be explained.

(a) C: Added to increase strength, but the appropriate amount is up to 0.10% so as not to impair the damping effect.

(b) S1: In addition to acting as a deoxidizing agent during melting and refining, it increases the maximum magnetic permeability of the alloy itself and is effective in promoting vibration damping effects, but adding a large amount will impair plastic workability and toughness. A range of up to 4.5% is suitable.

(c) Mn: In addition to acting as a desulfurization deoxidizer during melting and refining, Mn is effective in promoting hot workability of the alloy itself.
Contain up to 3.0%.

(d) Cr: Since it is an essential element for stabilizing ferrite and ensuring a damping effect, it is contained in a range of 5 to 35%. A particularly preferred range is 10 to 26%. (e)C
O: In the Fe-Cr domain wall displacement type alloy, the addition of CO increases magnetostriction and is effective in stabilizing ferrite during annealing at 950°C or less, so it should be added in an appropriate amount within the range of 30%. is desirable.

(f) Al: In addition to acting as a deoxidizing agent during melting and refining, it is effective in stabilizing ferrite and promoting vibration damping effects, and the range that does not affect plastic workability and magnetostriction properties is up to 8.0%. range.

Note that since the effects of adding SiIAl are almost similar, either one or both of them are included.
(卜) V: 0.05-3.0%, MO: 0.
05-5.0%, Nb or/and Ta: 0.05-5.0%
2.0%: One or more types (0.05 to 6.0% in total) are included because effects such as increased magnetostriction, promotion of damping effect, and improved corrosion resistance can be expected.

(f) S: 0.05~0.20%, Pb: 0.03~
0.30%, Se: 0.03-0.20%, Te: 0.
01-0.20%, Bi: 0.03-0.30%, Ca
: 0.001 to 0.030%: At least one element within the above range is included in order to improve machinability without impairing the vibration damping effect, plastic workability, strength, etc. of the alloy member of the present invention.

The alloy member of the present invention having the above-mentioned alloy composition was prepared in advance by 80%
Annealing is performed in a temperature range of 0° C. or higher, and then a surface hardening layer is formed within 80% of the total surface area of the alloy member. Hereinafter, the present invention will be specifically explained using examples.

Example 1: When a surface hardening layer is formed by carburizing method A test material (10 mm diameter x 2
After annealing the 50ml length) using 850 CX 1hr furnace cooling, the surface skin is cleaned by pickling, and then predetermined areas are treated to prevent carburization (e.g., copper plating). Gas carburizing was performed using a mixed gas to which gas was added, heating and holding at 900°C for 6 hours, followed by quenching at 100°C and tempering at 750°C.

In addition, the sample material SC-1 is an uncarburized material, SC-2 or SC
-4 was carburized by the corresponding surface area from one end of the sample. S
C-5 is a fully surface carburized material, SC-6 is 25W from one end of the sample! This is a sample in which carburized layers and carburization prevention layers were formed alternately at intervals of l. Next, these test materials were maintained in a free vibration state, and a constant impact force was applied to give them vibration, and the vibration damping state was observed using a synchroscope. The results are shown in FIG.

According to Figure 2, which shows the relationship between carburized area ratio and vibration damping effect,
It was found that if the carburized area ratio was within 80% of the total surface area, the damping effect was hardly impaired, and carburization had little effect on the damping effect. Example 2: When a hardened surface layer is formed by metal plating, metal spraying, or metal diffusion infiltration method A test material (101 W! diameter x 250 mm length) consisting of the chemical components listed in Table 2 was heated at 850 CX1 hr.
After annealing by P cooling, the surface skin was cleaned by pickling, and then a hardened surface layer was formed by the means shown in Table 3. The vibration damping condition was measured in the same manner as in Example 1. The results are shown in Figures 3, 4 and 5.

The measurement results shown in the figure show that as the area ratio of the surface hardening layer increases, the vibration damping ability is slightly impaired. However, if it is within 75%, the effect is relatively small, as can be seen from the curve shown in FIG. 6 showing the decreasing tendency of the damping effect.

As described above, the present invention provides a case in which a hardened surface layer is formed in order to improve wear resistance without substantially impairing the original vibration damping effect of a ferrite domain wall displacement damping alloy whose main alloy components are iron and chromium. This was started from the knowledge of how much the area ratio can be tolerated, and it was found that it is approximately within 80%.

Therefore, it is desirable that the total surface area of a damping alloy member required to have wear resistance is adjusted to be at least 1.25 times the required surface area. According to the results of wear resistance tests of surface-hardened damping alloy members, it has been confirmed that among the above-mentioned treatment methods, the metal spraying method is the most excellent.

[Brief explanation of the drawing]

Figures 1, 2, 3, and 4 are diagrams showing the vibration damping status of alloy members treated with carburizing, hard chrome plating, metal spraying, and boronizing, and Figures 5 and 6 are diagrams showing the tendency of the damping effect of alloy members treated as described above to decrease. It is a figure showing the relationship with a processing area rate.

Claims (1)

[Claims] 1 By forming a surface hardening layer within 80% of the total surface area of the alloy member by carburizing, metal plating, metal or ceramic spraying, or metal diffusion penetration treatment, sufficient wear resistance for practical use can be achieved. and an iron-chromium vibration damping alloy characterized by being imparted with vibration damping ability.