JP2006257508A - Alloy for nonferrous molten metal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an alloy for nonferrous molten metal having excellent erosion resistance, wear resistance, oxidation resistance and heat retaining properties as the one applicable to various erosion resistant alloys used in contact with nonferrous molten metal. <P>SOLUTION: The alloy for nonferrous molten metal has a composition comprising, by mass, 1.0 to 4.0% C, 0.2 to 4.0% Si, 0.1 to 0.5% Mn, 4.0 to 10.0% Ni, 10.0 to 25.0% Cr, ≤9.0% Mo, 4.0 to 15.0% V and 0.1 to 0.4% S, and the balance Fe with inevitable impurity elements. The alloy further comprises one or more kinds selected from <0.2% W, ≤5.0% Co, ≤10.0% Nb and ≤3.0% Al. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an alloy excellent in melt resistance, wear resistance, oxidation resistance and heat retention used in contact with a non-ferrous molten metal such as an aluminum alloy, a zinc alloy or a magnesium alloy.

  In recent years, non-ferrous alloys such as aluminum alloys and magnesium alloys have been widely used for manufacturing various components such as automobile products and home appliances. When manufacturing these products, members used in contact with molten non-ferrous metal, such as die-cast sleeves, gas blowing pipes, cores, stalks, gate members, ladles, etc. are resistant to melting, abrasion and acid. The heat resistance and heat retention are required.

  As this type of member, a member made of alloy steel for hot mold typified by SKD61 is generally used. In recent years, from the viewpoint of improving productivity and quality, further resistance to melting damage, wear resistance, oxidation resistance, and heat retention have been demanded.

  For example, in Patent Document 1, the chemical components are in a weight ratio of C: 2.4 to 3.8%, Si: 0.2 to 2.6%, Mn: 0.1 to 2.0%, P: 0 0.05 to 0.5%, S: 0.005 to 0.2%, the balance Fe and impurity elements are included, and formed using a birch-based material having carbide and a base metal structure, A non-ferrous metal melt member is described. The white birch-based material further has chemical components in a weight ratio of Ni: 0.1 to 4.0%, Cr: 0.1 to 2.5%, Mo: 0.1 to 2.0%, V: 0 It is described that 1 type or 2 types or more in 1-2.0% are included.

JP 2002-194477 A

  However, conventional non-ferrous metal melt members such as Patent Document 1 have not yet been sufficient in resistance to melting, abrasion resistance, oxidation resistance and heat retention. Further, in particular, there is a problem in that the shape is formed by machining, which requires a large machining cost, which requires a long time for machining and increases the cost.

  Therefore, the object of the present invention is to be applied to various corrosion resistant alloys used in contact with non-ferrous molten metal, and has excellent resistance to melting, wear resistance, oxidation resistance and heat retention and machinability. It is to provide an alloy for non-ferrous molten metal which is excellent in the above.

  The non-ferrous molten metal alloy of the present invention is, by mass, C: 1.0 to 4.0%, Si: 0.2 to 4.0%, Mn: 0.1 to 0.5%, Ni: 4 0.0 to 10.0%, Cr: 10.0 to 25.0%, Mo ≦ 9.0%, V: 4.0 to 15.0%, S: 0.1 to 0.4% It consists of the remainder Fe and inevitable impurity elements.

  Further, the non-ferrous molten metal alloy may contain at least one of W <0.2%, Co ≦ 5.0%, Nb ≦ 10.0%, and Al ≦ 3.0% by mass%. Features.

  The chemical component (mass%) of the nonferrous molten metal alloy of the present invention is preferably in the following range.

C: 1.0-4.0%
C is necessary for the formation of carbide for improving the wear resistance and the improvement of the hardness of the base during quenching and tempering by solid solution in the base. C produces a hard carbide that contributes to an improvement in wear resistance. If C is less than 1.0%, there is little crystallization of hard carbide effective for improving the wear resistance, and there is a shortage of C dissolved in the matrix, so that sufficient matrix hardness cannot be obtained even by quenching. On the other hand, if it exceeds 4.0%, the hard carbide becomes coarse and the amount of crystallization becomes excessive, and the toughness tends to deteriorate.

Si: 0.2-4.0%
The content of Si is preferably 0.2 to 4.0%. Si acts as a deoxidizer and is contained in a hard carbide by replacing it with elements such as W and Mo. Therefore, it is effective for saving expensive elements such as W and Mo. is there. If Si is less than 0.2%, the deoxidation effect is insufficient and casting defects are likely to occur. If it exceeds 4.0%, embrittlement tends to occur. Therefore, the content of Si is set to 0.2 to 4.0%. However, if Si exceeds 2.0%, the machinability effect tends to saturate, so 0.2 to 2.0% is more preferable.

Mn: 0.1 to 0.5%
The Mn content is preferably 0.1 to 0.5%. Mn has a deoxidizing action like Si. When the Mn is less than 0.1%, this deoxidation action is deteriorated. When Mn exceeds 0.5%, the melt resistance and oxidation resistance are inferior. Further, segregation of carbides occurs and the strength deteriorates. Further, Mn is necessary for forming a compound with S (sulfurized inclusions) and improving machinability, and is set to 0.1 to 0.5%. The Mn content is preferably 0.15 to 0.5%, more preferably 0.2 to 0.5%.

Ni: 4.0 to 10.0%
The content of Ni is preferably 4.0 to 10.0%. If the content is less than 4.0%, the martensite of the metal structure is likely to occur. On the other hand, if the content exceeds 10%, segregation occurs and the base becomes soft. Moreover, corrosion resistance is also improved by mix | blending 4.0% or more.

Cr: 10.0-25.0%
The Cr content is preferably 10.0 to 25.0%. This is because if the content is less than 10.0%, stable austenite cannot be crystallized and the corrosion resistance is lowered. On the other hand, if it exceeds 25.0%, segregation occurs and the strength is deteriorated. Become.

Mo ≦ 9.0%
The Mo content is preferably 9.0% or less. Mo is effective for stabilizing the base, and when Mo is contained, if its content exceeds 9.0%, the crystallization of the hard carbide is made unstable and the corrosion resistance is deteriorated.

V: 4.0 to 15.0%
V forms a hard MC-based carbide, M ₄ C ₃ -based carbide, which contributes most to the improvement of wear resistance. When V is less than 4.0%, the generation of carbide is small and the wear resistance is insufficient. If V exceeds 15.0%, MC and M ₄ C ₃ carbides are agglomerated and segregated during solidification to cause brittle deterioration, which is not preferable. A more preferable V content is 8.0 to 12.0%.

S: 0.1 to 0.4%
S becomes sulfide inclusions such as MnS and improves the machinability of the material. The most characteristic feature of the present invention is that machinability is improved by the addition of S. If the amount of S is too much, the mechanical properties deteriorate, so 0.1 to 0.4% is preferable.

W <0.2%
Co ≦ 5.0%
Nb ≦ 10.0%
Al ≦ 3.0%
About W, Co, Nb, and Al, what is necessary is just to mix | blend suitably according to the objectives, such as fusing resistance, abrasion resistance, and oxidation resistance. Even if these are blended singly, there is an effect, but a more excellent effect can be obtained by blending them in combination.

  In addition, the non-ferrous molten metal alloy of the present invention has a thermal conductivity as small as 11-12 W / m · K as compared to the conventional SKD61 steel, so that the alloy of the present invention is a die-cast sleeve liner that requires heat retention, for example. When applied to the material, there is almost no heat transfer from the liner material to the outer cylinder of the die-cast sleeve, and the heat retention is good.

  The non-ferrous molten metal alloy of the present invention is suitable for a member used in contact with a non-ferrous molten metal such as an aluminum alloy, a zinc alloy, and a magnesium alloy. Specifically, a die-cast sleeve, a gas blowing pipe, a core , Stalk, gate member, ladle, plunger tip, heater tube, thermocouple protection tube, degassing rotor, mold, weir insert, lance pipe, and other various members.

  Moreover, the member using the alloy for nonferrous molten metal of this invention can be manufactured by well-known methods, such as a stationary casting method, the centrifugal casting method, the overlaying method, and the sintering method. Furthermore, the nonferrous molten metal alloy of the present invention may be used not only by itself but also by coating the surface of a substrate such as steel.

  The test materials shown in Table 1 were prepared. Specimen No. 1-No. 3 is an alloy material for non-ferrous molten metal of the present invention, specimen No. No. 4 is a comparative material, sample material No. 5 is a SKD61 steel equivalent material.

  These test materials No. From 1 to 5, round bar-shaped test pieces each having a diameter of 10 mm and a length of 100 mm were collected and used as test pieces for a resistance test against melting damage. Using these test pieces, a rotational erosion test for molten aluminum alloy was performed to examine the erosion resistance. In the rotational melting experiment, each test piece was immersed in a molten aluminum alloy (ADC12) held at 720 ° C. 50 mm from the tip, and the test piece was rotated at 100 rpm. (% Weight loss) was measured.

  The test material No. From 1 to 5, test pieces having a diameter of 10 × length of 15 mm were collected and subjected to an abrasion resistance test. In the wear resistance test, an abrasive wear test was applied to measure wear loss. The abrasive wear test was performed by pressing each test piece against a SiC abrasive sandpaper (# 400) rotating at 150 rpm at a pressure of 90 N for 3 minutes. Evaluation was performed by measuring weight loss after the test.

  In addition, the test material No. From 1 to 5, test pieces having a diameter of 10 × length of 10 mm were collected and subjected to an oxidation resistance test. In the oxidation resistance test, the increase in oxidation after being held in an air atmosphere furnace at 800 ° C. for 48 hours was measured.

  Further, the test material No. From 1 to 5, test pieces having a diameter of 10 mm and a thickness of 3 mm were collected and subjected to a thermal conductivity measurement test. The thermal conductivity was calculated by measuring the specific heat and thermal diffusivity at room temperature in accordance with the laser flash method JIS R1611.

  Next, the test piece of the present invention material and the comparative material were processed to a size of 100 mm × 200 mm × 100 mmH, and subjected to a machinability test. The machinability test uses a high-speed 10 mm diameter two-flute end mill, samples are processed under the conditions of a rotation speed of 800 rpm, a feed of 100 mm / min, a cutting depth of 1.5 mmW × 10 mmH, and a cutting distance of 10 m, and wear of the cutting tool. The amount was measured.

  The test results are shown in Table 2. From Table 2, No. which is the material of the present invention. 1-3 are No. which is a conventional material. Compared to 5, it was found that the melt resistance, wear resistance, oxidation resistance, and heat retention performances were significantly superior. Further, due to the effect of S, the material of the present invention is comparative material No. Compared with conventional material No. 4, machinability improved more than twice. A machinability equivalent to 5 was achieved.

  According to the non-ferrous molten metal alloy of the present invention, since it is excellent in resistance to erosion, wear resistance, oxidation resistance and heat retention, die casting sleeve, gas blowing pipe, core, stalk, gate member, ladle, etc. The members used for various nonferrous molten metal alloys used in contact with the nonferrous molten metal can be used stably for a long period of time, and the production efficiency can be increased. Furthermore, since it is excellent in machinability, it can be manufactured and maintained at low cost.

Claims (2)

In mass%, C: 1.0 to 4.0%, Si: 0.2 to 4.0%, Mn: 0.1 to 0.5%, Ni: 4.0 to 10.0%, Cr: It contains 10.0 to 25.0%, Mo ≦ 9.0%, V: 4.0 to 15.0%, S: 0.1 to 0.4%, and the balance being Fe and inevitable impurity elements. An alloy for non-ferrous molten metal. Furthermore, it contains at least one of W <0.2%, Co ≦ 5.0%, Nb ≦ 10.0%, and Al ≦ 3.0% by mass%. The alloy for nonferrous molten metal as described.