JPS609858A - Nonmagnetic corrosion-resistant material having high strength - Google Patents

Abstract

PURPOSE:To provide a titled member to be used for various machines, apparatus, etc. by consisting the same of specifically composed Mn, Cr, V, C, N and Fe, etc. CONSTITUTION:A nonmagnetic corrosion resistant member having high strength contains 10-40wt% Mn, 10-25% Cr, 0.3-3.0% V, <0.05% C and 0.2-1.5% N, contains further <=5.0% Mo according to need and consists of the balance Fe and incidental impurities. Said member is suitable for use with various machines, apparatus, etc. The Mn among the above-mentioned compsn. components is required to be >=10% in order to obtain magnetism as stable austenite but if >=40%, workability deteriorates. The Cr contributes to an improvement in corrosion resistance and V to an improvement in strength through strengthening by solutionization as well as to an improvement in work hardening and an improvement in strength aging. N contributes to an improvement in strength through strengthening by solutionization and Mo to an improvement in corrosion resistance and strength with addition of a small amt. C provide the effects such as an improvement in strength through strengthening by solutionization or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a high-strength non-magnetic corrosion-resistant member E for use in various types of machinery and equipment.

[Technical background of the invention and points of connection]

Conventionally, Cr-Ni-Fe austenitic stainless steel and high manganese non-magnetic steel such as Mn-C-Fe or Mn-C-Cr-Fe have been known as non-magnetic steels used in various types of machinery and equipment. ing.

However, the former Cr-Ni-Fe austenitic stainless steel has low yield strength, and the latter high manganese nonmagnetic steel has poor corrosion resistance.

[Object of the present invention]

The present invention aims to provide a non-magnetic and high-strength corrosion-resistant member suitable for use in various types of machinery and equipment.

[Summary of the invention]

The present invention is based on the results of various experimental studies on conventional non-magnetic high manganese steels and the discovery that non-magnetic, high-strength, corrosion-resistant members can be obtained with a limited chemical composition.

That is, the high-strength non-magnetic corrosion-resistant member according to the present invention contains Mn 1 (1-4096, Cr 10-2) at 1 weight percent.
5'l.

VO, 3~8.0%, CO, 05% not #NO, 2
~1.5 @ High strength, corrosion resistant member consisting of balance Fe and incidental impurities or Mn 10-40%, Cr 10
~25%, VO, 3~3.0%, CO less than 105NO, 2~0.5%, Mo 5% or less, balance Fe
It is a high-strength, corrosion-resistant member consisting of aluminum and incidental impurities.

Here, the reasons for limiting the composition of the high-strength non-magnetic corrosion-resistant member according to the present invention will be explained.

Mn (manganese) is an austenite-forming element,
In order to obtain non-magnetism as stable austenite, it is necessary to have a coefficient of at least 10 or more, preferably 15 or more. However, since a large amount of content deteriorates processability, the content is limited to 40% or less. Note that if the high-strength corrosion-resistant member according to the present invention requires low thermal expansion, the Mn content' should be set at 23~23.
It is desirable to set it to about 27 inches.

Cr (chromium) is an element necessary to improve corrosion resistance and strength, and it is necessary to have a concentration of at least 10%, but if it is contained in a large amount, it promotes the formation of ferrite and deteriorates workability, so it should not exceed 25%. do.

■(Vanadium) is an element necessary to improve strength by solid solution strengthening, increase work hardening, and improve strong ffLl by aging. If it exceeds this range, the workability deteriorates, ferrite is formed, and non-magnetic properties are lost, so this range is set.

N (nitrogen) is an element that stabilizes austenite and improves its strength through solid solution strengthening, and is preferably at least 02% and preferably 03% or more.

However, since a large amount of content would make melting difficult, the limit was set to 1.5.

Mo (molybdenum) is an element that improves corrosion resistance and strength, but addition of a large amount impairs workability and produces ferrite, making it non-magnetic, so it was set to a coefficient of 5.0 or less.

Like N, C (carbon) is an element that stabilizes austenite and improves its strength through solid solution strengthening, but its content is limited to less than 0.05%, since a large amount of it impairs corrosion resistance.

Note that it is possible to add Ni for the purpose of stabilizing austenite, to add Cu for the purpose of improving corrosion resistance, and to add Sl for the purpose of adding acid during melting.

[Embodiments of the invention]

An alloy having the composition shown in Table 1 was melted and cast using a pressurized high-frequency melting furnace to obtain an ingot.

Then, after hot forging and hot rolling, 1150
The mixture was heated at 0 for 1 hour and then cooled.

Continuing from Table 1, Example 1.2.4 and Comparative Example 1.2 were subjected to 31 cold workings, and then test pieces were cut out and tested.

Further, in Example 3 and Comparative Example 3, after aging treatment was performed at 700''O for 5 hours, test pieces were cut out and tested.

Tests included tensile tests, corrosion tests, magnetic permeability measurements, and wear tests. The test results are shown in Table 2.

The wear test was conducted using an Odate type wear tester with a final load of 7 kg, the mating material being SNCM8 (Hv 180), and a wear rate of 2 m.
/see was used. In addition, the corrosion test was performed by immersing the test piece in water at room temperature for one week and evaluating the rusting state on the surface.

Table 2 [Effects of the Invention] As is clear from Table 2, Comparative Example 1 has the same strength, magnetic permeability, and wear resistance as Example 1.2.4 according to the present invention, but has poor corrosion resistance. Moreover, Comparative Example 2 had low strength and was not nonmagnetic.

Moreover, Comparative Example 3 has the same strength, magnetic permeability, and wear resistance as Example 3 according to the present invention, or has poor corrosion resistance.

As described above, the high-strength, non-magnetic, corrosion-resistant member according to the present invention is an industrially extremely useful material that has excellent strength, magnetic permeability, surface permeability, and corrosion resistance.

Agent: Patent attorney Noriyuki Chika (1 other person) 353-

Claims (1)

[Claims] (1) Weight bar centimeter Mn 10-40 (lr, C
r1O~25 section. ■0.3~8.0chi, less than C005%N092~1.5
Remaining part (2) Mn in weight percent 10-40'1
6, Cr 10-25%. (2) A high-strength non-magnetic corrosion-resistant member characterized by comprising: 0.3 to 80%, CO less than 0.05%, NO2 to 1.5% MO 5.0% or less, residual Fe, and undesirable materials.