JPS596349A - Ni-cr corrosion resistant alloy capable of hot processing - Google Patents

Abstract

PURPOSE:To provide a Ni-Cr type alloy capable of hot processing and excellent in decorative property and corrosion resistance, obtained by containing Cr, Al, Mg and Ca in Ni in a specific ratio. CONSTITUTION:A Ni-Cr type alloy containing, on the basis of a wt., 20- less than 30% Cr, 3-8% Al and, according to necessity, one kind or more 0.01- 1.0% Be, 0.01-1.0% Zr and 0.1-1.0% Nb and one kind or more 0.001-1% Mn and 0.001-0.05% Ca and comprising the remainder Ni and inevitable impurities is prepared. By using this alloy, a spectacle frame relatively low in cost and good in quality can be prepared by a mass production system.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a Ni--Cr alloy that can be hot worked and has excellent decorative properties and corrosion resistance.

For example, decorative metal materials used for eyeglass frames, watch cakes, etc. are required to have corrosion resistance and high hardness in order to withstand long-term use and maintain their decorative properties. Various Ni-Cr alloys have been reported as materials that meet these demands, but each has advantages and disadvantages.

In Ni-Cr alloys, corrosion resistance generally improves as the Cr content increases, but an increase in Or makes hot working such as hot rolling or hot forging difficult or impossible. Materials that cannot be hot-processed have limited manufacturing methods, are not mass-producible, and are expensive. Moreover, the ability to perform hot working has the advantage of making the internal structure uniform and helping to improve quality.

Therefore, the present invention achieves the following without sacrificing corrosion resistance or hardness.
The purpose of this alloy is to provide a corrosion-resistant alloy with good hot workability by limiting the amount of Cr and At and adding Mg and/or Ca. It was successfully developed.

That is, the invention of item 1 has a weight ratio of Or 20 to 30.
% (but does not include 309') Contains At 3-8%, other KMg 0.001-0.1%, cao, ooi ~ 0
0.05%, and the rest is substantially composed of Ni except for unavoidable impurities, and the second item of the invention is an alloy containing one or two of the following:
T10.5~2%, BeO, 01~1%, Zr
0.1-1. ．． This alloy contains one or more of Nb011-1% and Nb011-1%, has good hot workability, and has sufficient hardness and corrosion resistance to maintain decorative properties.

The reason for limiting the range of components in the present invention as described above will be described.

If Cr is less than 20%, corrosion resistance is poor, and if it is 30% or more, hot workability is inhibited. If At is less than 8%, it does not contribute to age hardening, and if it exceeds 8%, it deteriorates hot workability.

Ti, Be, Zr, and N'b are hardenable elements, and if each is less than the claimed range, they will not contribute to improving hardness, and if more than the claimed range, hot workability will be deteriorated.

Calcium and Ca are additive elements to improve hot workability, and if the amount is less than 0.01%, it has no effect on improving hot workability, and if Mg is more than 0.1%, C
When a exceeds 0.05%, it segregates at grain boundaries and actually impairs hot workability.

Next, examples of the alloy of the present invention will be described.

A sample of a predetermined component was first melted in a vacuum in a high-frequency melting furnace, and cast into a mold with a plate thickness of 40 mm, a plate width of 60 mm, and a length of 1,200 mm.

These were heated to 1,100 to 1,200°C and hot rolled at a reduction rate of 90% to a thickness of 6, and the quality of hot workability was determined based on the presence or absence of cracks.

After that, solution treatment was performed at 1100-1200°C for 1 hour to create a mirror finish, resulting in artificial sweat, ■5% HNO, ? ,■SO
It was immersed for 48 hours at a temperature higher than COGAS, and its corrosion resistance was examined by visual inspection.

Samples that had been subjected to solution treatment were subjected to aging treatment at 600° C. for 2 hours, and the Vickane hardness was measured.

For comparison, a sample containing components outside the scope of the claims of the present invention was prepared in the same manner as above, and a rolling test was conducted in the same manner as above.
It was subjected to solution treatment and its corrosion resistance and hardness were measured.

These results are summarized in Table 1.

As shown in Table 1, the alloy of the present invention had both high hardness and corrosion resistance, and also exhibited good hot workability. On the other hand, the comparative alloys had poor hot workability, or those with good heat workability did not have sufficient hardness and also had insufficient corrosion resistance.

In the case of the alloy of the present invention, if it is desired to obtain a higher hardness, the alloy may be subjected to cold working to work harden it after solution treatment, and then subjected to aging treatment.

As described above, the alloy of the present invention has good hot workability, high hardness, and good corrosion resistance, so it is possible to mass produce eyeglass frames, watch cakes, etc. of excellent quality at a relatively low price, and it can be used industrially. Extremely useful.

Applicant: Sumitomo Special Metals Co., Ltd.

Claims (2)

[Claims] (1) Contains 20-30% Cr (but not 30%) and 8-8% At by weight, and 0.001-0 Mg
．． 1%, CaO, 0.01-0.05%, and the remainder is substantially Nj- except for inevitable impurities. (2) Contains Cr 20-80% (but does not include 80%) and At 8-8% by weight, and Ti 0.5-2.96
, BeO,01-1,0%, ZrO,01-1
, 0% and one or more of N-b O, 1-1.0% and Mg0.001-0.1%, C
A corrosion-resistant Ni-Cr alloy that can be hot-worked, containing one or two of O,001 to 0.05%, and the remainder being substantially N1 excluding unavoidable impurities.