JPS5822353A - Cast-welding aluminum alloy and cast-welding method - Google Patents

Abstract

PURPOSE:To obtain an Al alloy having strong cast-welding power, by letting Al contain specified amounts of one or more of Si, Mg, Cr, Ti and Zr. CONSTITUTION:The composition of a cast-welding Al alloy is determined as, by wt%, one or more of 2-6 Si, 1.2-9 Mg, 0.4-1 Cr and 0.15-0.8 Zr, and the balance Al and inevitable impurities. A steel pipe, degreased by sand-blasting and preheated at 800 deg.C or so, is located in a main mold 2a. The melt 5a of said cast-welding Al alloy is poured into the main mold 2a. After the laps of 15sec, the melt 5a is charged with hydrostatic pressure of 200kg/cm<2> or more by pressing it with a press punch 6a. When the steel pipe is welded to an Al alloy by use of the welded joint formed in this way, the welded article satisfying pressure-resistance and joint strength is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a nine-casting method using an aluminum alloy and a -alloy that have strong casting adhesion to Fi, iron-based or steel-based metals, Wit (hereinafter referred to as iron-based metals, etc.), and K. It is related to.

Methods for joining A/Mini to ferrous metals, etc. include 1) Mechanical fraud methods such as screwing during riveting;
Pressure welding methods such as cold pressure repellent and electrical resistance.

Brazing, hemming, etc. M1! KFif
However, no matter which method is adopted, it is possible to use A711/L-ium alloys, iron-based metals, etc.
Heat transfer is poor due to poor adhesion at the bonding interface.

It has been difficult to apply it to applications that require high binding strength and pressure resistance.

In response to these demands, we developed a technology that metallurgically combines a saponified metal and an aluminum alloy to form a uniform diffusion alloy layer at the interface between the two metals. jI) A large number of inventors, etc. tf
JK @ Kosho 554-lB209t'JK.

However, recently, V! In recent years, towers have become required to have pressure resistance and strength at altitude 1, and the strength of casting has been increased to N#.

The present invention #i has been made in view of this situation, and its purpose is to form a strong diffusion alloy layer at the interface between a IIk metal or the like and an alloy. By specifically limiting the component composition of #i aluminum alloy for sowing soda, it is possible to improve the casting adhesion between the iron-based metal sieve and the aluminum alloy, and to further improve the casting strength when casting the aluminum alloy around the aluminum alloy. By setting suitable conditions, it is possible to improve the 111m landing force.

However, the aluminum alloy of the present invention is an aluminum alloy for casting that is bound to an iron-based metal sieve, and has a silicon content of 2 to 2.
Magnesium: 1.2 to 9 Oam, Chromium: 0.4 to 1.0 Oam, Titanium: 0.16 to 1.0 Oam
mm, zirconium: 0.1 to a, S weight (W) to 1 (W), # is the same as the tensile strength of 4M in the past (9) #A friend who can wear AVMium alloy. The remaining inventors used an aluminum alloy that satisfies the above requirements and developed I! We have also achieved a certain level of success in methods of improving casting strength, and we have developed a method to improve the casting strength of metals, etc. @L, after pouring the aluminum rough alloy molten metal into this # life mold.

200 Kv/a? The gist of this method is to apply the above hydrostatic pressure to form a diffusion alloy layer between an aluminum alloy and a metal fitting such as an iron-based metal.

In other words, the purpose of improving the casting force is to use pressure.

By adjusting the binding conditions such as temperature, pressurization start time, pressurization holding time, etc.! I can do it.

In this respect, a certain level of success has been achieved in the Joki Senm. Shikajina Hat and other recent aFi-m dislikes and p# wearing power I! Since it is desired to improve the quality of the product, there is a limit to the amount of ingenuity from the conventional point of view, and it is not possible to meet the above request. Therefore, the book 1l Jti 14 people cast m#c pouring a/ (= 5 alloys).

The present invention was developed based on the idea that excellent casting strength could be obtained by appropriately selecting alloy components and blending amounts, and as a result of extensive research.

The inventors carried out research using the experimental apparatus shown in Fig. Fi@1. Inside this V-Der 1, there is a foundry association 2, and the donation IJJJ1! A sliding take-out rod 8 is provided in order to push out the * from the ruler 1.

In the experiment, cast metal X4 made of the same (about too" cyc preheated L199.1S) pure iron was placed in gold m2 preheated to about 820±20CK, and casting was started from above the amount of gold at a severity of +100. Inject aluminum alloy lead metal 6 whose temperature is adjusted to ℃.After injection.

Insert the pressurizing punch 6 into the mold drilling hole from above the hot water, and press 14.
00 Kg/J (P pressure is applied to the lead metal. #*In the experiment, heat insulating material 7.τ was placed on the bottom and top sides of the Fi lead metal.

1. Using the above method KsP, the components of the two and five alloys are mixed and casted.1. A sample was cut out from the cast part and subjected to 41 tests, and the following results were obtained.

(1) When silicon was added to Alζ leek 5, the results were as shown in Table 1.

As you can see in Table 1, the draw is 4! I strength is silicon addition j1
is 042~1. In the case of Onl 俤, there is not much difference from 11aAI, but when it becomes 44 Doryu Yu, it improves to #/- to 44.

It is about twice that of pure hlcoLBKtt/-.

On the other hand, if the strength of Keijo Kei Kaken is 7 or more, a uniform alloy layer is not formed at the interface with the iron metal fittings, so the contact strength varies, and the overall effect of improving the age of 8I is small. Become. In order, the most evenly added side of Danka was 14 times Fi 2 to 6 weight.

(When MagneVium is added to Ria J411ium, the results are shown in Table 2).

No.! As seen in the table, the amount of shish magnesium added is 1.21
The tensile strength of less than 1 amount of ginseng is small, but IJ, 1. ? and 6
．． When it reaches 6111111, it improves greatly to more than to;=-J.

On the other hand, when the amount of Mg added becomes 10 gm-, the alloy layer becomes too thick (45 gm), and the tensile strength actually decreases.

In retrospect, the optimum addition ratio of Magne VtsufuO was IJ to 9-polysene.

In addition, as a result of conducting experiments on other additive elements in the same manner as above, it was found that Cr, T'l, and Zr are effective, and the optimum addition ratio for each is CF20.4~1.01111m
I T j : 0.15~O, J1] 1i Quantity, z
r: (Ll~o, 81i quantity excellent and 9.th11!!
If the addition ratio is less than the above range, the effect of improving the traction force *M will be small, and if it exceeds the above range, the solidification start moisture content of the KFi aylnium alloy will be high. ] It was inappropriate.

Furthermore, if the above-mentioned additive elements are suitably combined within the range of the addition ratio of jIM, the IrK relaxation tensile strength can be ensured.

Reference photo 1 is a series of representative metal microstructure photos of an alloy that exhibits good tensile strength. An alloy layer with a uniform thickness is formed over the entire interface. )
There is a tongue-like F@RA15 (η) phase, and A/Linike F6
Phases of A/ and ( are recognized.

By the way, if you look at the fracture surface of sample O after the tensile contact test, the percentage
F az A l 5 (17) due to rupture,
? , almost no rupture was observed in the FeA/3(1) phase.
ktlh9. Generally, as the content of the effective additive s in the aluminum alloy increases, the thickness of the alloy layer decreases and the formation of tongue-shaped F@2A15 occurs to a small extent (as compared to an alloy layer containing only FeA/3). In the present invention, the formation of the FiF•If!A/6 phase is not observed within the range of the optimum addition ratio of the 1# effective dopant.

It is thought that this creates an image and contributes to improving the tensile strength between the deposited metals.

As described above, if the A/M alloy of the present invention is used for casting, excellent tensile fineness can be ensured regardless of the casting method.

On the other hand, non-inventors have continued to research into fertilizers that bring out the advantages of the above-mentioned AV aluminum alloy to the maximum. That is, in the method shown in the prior application, the casting metal is pure aluminum or aluminum alloy (AC4C).

It has been found that using aluminum alloys such as ACaA, etc.) is not the optimal binding method for the aluminum alloys of the present invention, which have a different composition from those. Therefore, as a result of studying the method of tying the material and conducting experiments by carefully changing the pressure conditions, we were able to complete the method of tying the aluminum alloy of the present invention.

II! Using the crucian carp shown in the igt diagram, the pressure (hydrostatic pressure) and pressurization start time were varied to make the #-based metal and the present invention A W (
= After binding the ram alloy, a test piece of the cast part was taken and subjected to a fluorescent penetrant test.

As shown in the figure, under no-load pressure (100 Kl/cdC), the formation of an alloy layer was insufficient and poor adhesion occurred.

At 200Kl/6d or more, there were no defective parts and the adhesion was good. The combined effect of the casting conditions, that is, the pressure and the timing of starting pressurization, was as shown in Reference Photos 2 and 8.4. That is, reference photo 2, 311, 4 #i pressure is 800
h15#, 100Ky/d, 100Ky/ad.

Pressurization start time is 120 seconds after pouring, 120 seconds after pouring, 1
The graph shows the composite Ml black structure of the metal layer of the casting part when the 6-second edge is applied (however, the molten metal Fi pure A/(nirafu)).

Reference photo 2. R is the MMI that was pressurized after the MMI liquid around the stirrup metal X (iron) became low, and the former has a high pressure, so an alloy layer is recognized, but the alloy phase on the # side is thin, and the #device x1 It has not grown to the point where it has direction. On the other hand, the A/lium IIO alloy phase is thicker than spg, and the thickness of the alloy layer gold body is P greater than that in reference photo 1, and it exhibits good trout adhesion. In Reference Photo B, the eutectic zone of the alloy layer and the base material is not observed and diffused.On the other hand, even if the pressure is low, if the pressure start time is short, an alloy layer as shown in Reference Photo 4 is formed. However, cracks in the alloy layer were detected in the fluorescence test, and casting embedding is not a good idea. The above is a photograph of the structure in the case of pure aluminum = 9 and pure iron, and the effect of pressure and pressurization start time is the same when using alloy AJIL/minium, and the pressure is 200 K.
If it is 117611 or more, the shrine result shown in reference photo 8.4 will not be obtained. Even when pressurizing at fN200Kt/ad or more, there are many variations in the attachment force (pull M19!1 degree) depending on when pressurization starts. l! In order to maximize the strength, we decided to delay the start of pressurization until the solidification of the introduced metal [1 [7], and suddenly we obtained even better results.

The present invention is structured as described above.

In fields such as joining high-pressure pipes that require high pressure resistance and tensile strength! It appears that a bond with good sealing performance can be obtained with just one solid piece.

Next, examples of the present invention will be shown.

Example 1 The following was manufactured as a #W!-child for joining a steel pipe (material: 54RC) and a steel pipe (material: A6061). Namely, in Fig. 8, a steel pipe of 4 m (84w) was
mφ, 200 cm long) is sandblasted to remove rust, then 200"C#C spider-1 is preheated and placed in the main mold 2a which has been heated to 800°C in advance. This main mold 2 Molten metal 5a of aluminum alloy (S125, Mg: IJ, A/+ balance) is poured into the island at 7RO℃, and after 16 seconds, it is pressed with a pressure punch 6&, and the water pressure is 400 and 9/- is 2. Take a minute.Create it in this way and use the fittings w
4 tubes and 4 aluminum alloy tubes welded together.

A product satisfying pressure resistance and joint strength was obtained.

8 in both figures is a core.

[Brief explanation of drawings]

Figure 1 is an explanatory diagram showing the casting test of iron metal fittings and aluminum sieve, Figure 2 is an evaluation diagram of the results of the casting experiment using the pressing force and pressurization start time as factors, and Figure 8 is Fi implementation. FIG. 2 is an explanatory diagram of a tying device for steel pipes and aluminum alloys used in the example. 2... Mold 4... Casting metal fittings 6...
・s* g-Pressure punch applicant Kobe RIM Co., Ltd.

Claims (1)

[Scope of Claims] An aluminum alloy for casting which is deposited on a ferrous or steel-based metal VC#, silicon: 2 to 6 weight 91. Magne Vum; 1.2-9 weight tatami, Kurofu: 0.4-1.0 weight jH1
, fly: 0. I B-0,811 amount of ginseng, Siconium-0.1-0.8 selected from the group
Wearable aluminum elastomer five-alloy containing one or more ash and the remainder being aluminum and unavoidable impurities. (! 1 flkl or copper-based metal is installed in the casting mold, 11! I: 2-g weight range, magnesium: 1.2-9 weight range, chromium: 0.4 ~1.0 weight range e?J”: 0.1 SNO-11 weight range, dirunium:
After injecting 511 g of A/(nium and inevitable impurities) containing 1!1 or more selected from the group consisting of 0, 1 to 01 weight and p, f2 gl A method characterized by forming a diffusion alloy layer on the casting surface of an aluminum alloy and an iron-based or steel-based metal fitting by applying a hydrostatic pressure of 6 Ky/eJ or more.