JPS5954483A - Stainless clad bar steel and its production - Google Patents

Abstract

PURPOSE:To provide a titled bar steel which is inexpensive and has excellent corrosion resistance and workability by coating and melt-sticking a stainless steel pipe material by a hot rolling method on the surface of a blank material for a solid bar steel. CONSTITUTION:This stainless clad bar steel is produced by coating and press sticking a laminar coating part 2 consisting of a stainless steel pipe material around a core material 1 consisting of a blank material for a solid bar steel, for example, a round billet, by the press-contacting force of hot rolling. The production of such bar steel is accomplished by inserting first a round billet 3 into the above-described pipe material 4 having the inside diameter slightly larger than the diameter thereof, welding the end 3a of the billet and the end 4a of the pipe near the same, putting the same into a heating furnace and heating the same. The heated pipe material 4 and the billet 3 are hot-rolled with rolling rolls 5 whereby the pipe material 4 is press stuck to the surface of the billet 3.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to stainless steel/scrud long steel bars such as wire rods, steel bars, and flat steel having corrosion resistance, and a method for manufacturing the same.
2 Conventionally, C1 hollow stainless steel (M't;i'iJ, flat steel) has been known as long steel with corrosion resistance, but such hollow stainless steel bar has excellent corrosion resistance and is Since the entire material is made of stainless steel containing Cr and Ni, its cost is +g! Yes, but also has some weaknesses such as inferior free-cutting properties. 6, 1 (1) side, (Cr plating on the surface between the I-shaped carbon 92 / S; I plating table: Long steel products with surface treatment are known, but the price of such plated steel bars is 1000 yen per unit price for thick products, and 10 ton for thin products. , unit price is W
b<, and there was another failure point.

Unexploded 111.1 is a conventional stainless steel strip 01 as described above.
Or, in view of the shortcomings of surface-treated steel ∆, each piece of unfilled insert goods,)
i; Covering and welding stainless steel 1/spipe material on the surface of the shell material by hot roll rolling method (this is cheaper, has corrosion resistance &/7-2, and also improves the material of the bar material) It is an object of the present invention to provide stainless steel clad bar steel that has good workability such as bending workability, and also has strength similar to that of special steel, by selecting a suitable material.

The present invention will be explained below based on examples thereof. As shown in Fig. 1 and ffT 21+1, the stainless steel cladding according to the present invention is made of a hollow bar material, such as a round billet knot or by a base pressure welding force. , the coated and crimped strip λ((,l ′7
J! Maru. Types of bar steel materials that are the material of lIJ core material 1 In 1], carbon kabura, karasu tension steel 2 alloy steel*! i? J
Any material such as heat M/1M or free-cutting steel can be selected.

The stainless steel pipe H, which is the material of the covering part 2, may be of any type such as austenitic stainless steel, ferrite stainless steel, martensitic stainless steel, etc., but it is preferable that the core material 1 be It is preferable to select a stainless steel material having approximately/the same coefficient of thermal expansion as the thermal expansion coefficient. For example, if a round billet or a square billet of mild steel is selected as the core material 1, a PM thread stainless steel pipe material having approximately the same coefficient of thermal expansion as that of the mild steel may be used for the covering portion 2. To describe the dimensions of one embodiment of the bar steel of the present invention, the core of the product 1 has a cross-sectional area of 64 mm.
．． It is a 6 mA round bar, and a covering part 2 made of stainless steel pipe material having a cross-sectional area of 18.89 mrd in the thick part of the covering part 2 is covered and crimped onto it. That is, the product is a stainless clad steel bar with an outer diameter of 10 mm and a thickness of about 0.5 mm. Please note that the dimensions of each part in Figures 1 to 10 are not the same as the actual figures for the sake of clarity.

In this way, in the steel bar of the present invention, the core material 1 is covered with the coating part 2 derived from the stainless steel vibrator having corrosion resistance, and the thickness can be made thicker by C as required, so that the corrosion resistance is significantly improved. can be made larger. Therefore, the steel bar of the present invention produced by hot rolling can be used for the following purposes after cold drawing or the like. For example, rust resistance is required for motor shirts used underwater, impeller shafts for stirring chemical solutions such as various acids, conveyor rolls, and supplies for home gates, balcony fences, fences, and ground areas. Its utility value lies in the fields in which it is used. In addition, in this case, for example, as mentioned above, there are various types of bar stock to be used for the liquid core material 1, so it is possible to choose one with excellent tensile strength, one with high bending strength, or one with excellent free machinability. Next, the method of threading the long steel of the present invention will be explained using an example. First, as shown in FIG.
A light control billet 8 is prepared, and a 9f diameter 45 whose inner diameter is slightly larger than the diameter of the round billet 8 as shown in FIG. 4 is prepared.
A chrome-based stainless steel pipe material 4 with a body thickness of 2 ml is prepared. Next, without performing any particular cleaning process such as pickling on the inner surface of Table 1 11 of the round neck 3, the pipe, and the moon 4, without removing scale etc., as shown in Fig. 5. , insert the round billet 8 into the pipe material 4.

The end 8a of the fitted round billet 8 and the end 8a
(contact with the end portion 4a of the tube material 4) by partially melting the end portion 4a of the tube material 4 by means such as arc welding. 6 is the welded part.

The pipe piece 4 and the round billet 8, which have been combined and fixed in this way, are charged into a heating furnace and heated to a temperature of 1,150 to 1,200 ''.
Heat to j'N degrees.

Pipe material 4 and round billet 8 heated to a certain temperature,
As shown in FIG.
Roll. Roll rolling is carried out continuously using, for example, 12 rolling mills, and the 6th m indicates the final finishing roller. This is an example of a caliper (groove) for forming the strip 7 (m) in the figure. During this rolling, the pipe 4 and the round billet 8 are first deformed into an ellipse by the caliper 7. Due to this deformation, the billet Knot 8 is 11 of pipe material 4
It is inscribed in the whole 11. This is because when the circular billet 3 is deformed into an ellipse, its outer circumference expands and comes into contact with the inside 11ii of the hole 4. In this contact, the outer surface of the C billet 8 is pressed against the inner surface of the pipe buoy 4 with a large force, so that the two are substantially integrated by frictional force. Furthermore, since this integral body is rolled by the li-roll rolling roller 5, the pipe 4 and the round billet 1/t 8 are elongated due to the rolling force, but the surface of the round billet 80 and the inner surface of the pa-f buoy 44 are The scales that occurred were round billet 3 and pipe moon 4.
A slight elongation occurs in the 4th part of the body. Is this round billet 3 from this [1 to il, O out? blue show jib I
Jil, and the pa r buoy that sent out KX from Jth;:t 4
c) Heat pressure 7゛1 to 1 with the pressure of H-1 rolling
Therefore, the article 11j1 of the present invention is as follows: - The marble stone 14 is pressed into contact with the round billet 3 and is fixed to the round billet 3. '−%
111i are evenly distributed between them, with countless scales (',) having a pressure of 45 and a pressure i'i of 45, so the 1 of both 4 is strong. Therefore, even if there are mainly 1:'L cracks in a part of the coating layer 2 made of the Verib material 4, there is no fear that the coating J'42 will peel off from the core material 1. The long steel is pressed at crimping points where the stainless steel coating layer and the steel base material are evenly distributed. It can be bent without causing any damage.

In the present 9' projection, it is preferable that the coefficient of thermal expansion of the round billet 8 and the coefficient of thermal expansion of the pa/f plate material 4 be approximately equal. If you have any questions, please contact Mlli for stainless steel pipe material 4.
If the elongation is considerably larger than that of round billet l-8, for example in the case of Ni-based stainless steel, the stainless steel coating layer will compress the steel base material excessively during cooling after hot rolling, and as a result, the product will deteriorate after cooling. This is because it often causes distortion such as curvature.

If the size of the gap between the pipe buoy 4 and the round billet 8 before processing is too large, wrinkles will occur on the inner surface of the pipe material 4 during rolling, and the metal internal hammer of the pipe buoy 4 will be deformed. Since they are excessively large and irregular, there is a risk that the covering portion 2 of the finished product may become brittle. Conversely, if the gap is too narrow, it will be difficult to fit the round billet 8 into the pipe material 4. According to experiments conducted by the inventors, it was found that the difference between the inner diameter of the pipe material 4 and the outer diameter of the round billet l-8 is preferably about 8% to 4% with respect to the inner diameter of the pipe material 8. did.

I have described round billets above, but as a bar material, square billets are welded with square tip material. Of course, it is also possible to manufacture

As is clear from the above description, the bar of the present invention uses one core, one iron, and one piece of iron, and Q) Is the core material 7L covered with stainless steel pipe material? 1 (Pressure: i), so the price is 'c)?':b bow i) ",+zu, has great corrosion resistance,
Furthermore, by selecting C1's 11 as the core material, it has high tensile strength.

Heat-resistant? i:, +1 bending force j,) I:,, I was beaten by the free machinability, etc. (1) Stainless clad Jay Shu was involved) 7iC, and furthermore, the samurai cracked', 41- 1■
Since it is unnecessary to remove scales from the inner surface of the P-R-moon and the surface of the core material, which becomes the core material,
It also has the advantage of high work efficiency. Also, by changing the shape of the caliber to a different shape, for example by providing an uneven portion in the groove, it is possible to create various decorative rods with a curvature pattern to improve corrosion resistance.

[Brief explanation of the drawing]

The drawings are all for the purpose of explaining the embodiments of the steel bar of the present invention, and Figure 1 is a perspective view of the bar product of the present invention rolled into a round bar, and Figure 2 is a perspective view of the steel bar product of the invention rolled into a flat bar. A perspective view of the long steel product of the present invention, FIG. 8 is a perspective view of a round billet, FIG. 4 is a perspective view of a P/F, and FIG. 6 is a perspective view of a round billet fitted into a pipe. Perspective view showing inserted state, εJ'E
, (Figure i is a perspective view of the rolling roller during rolling. Agent Patent Attorney Higashijima 1st and 6th Figure 5 fs G Figure 424

Claims (2)

[Claims] (1) A coating layer made of stainless steel pipe material is placed around a core material made of empty bar steel material, which is covered with F! Stainless steel clad tea cake characterized by pressure≧()1 and “C”. (2) Inside the stainless steel pipe material, there is a hollow pipe z (the material is h', 1 (7
tL-1 The end of the long steel material and the end of the pipe material close to the end are welded, the fitted pipe material and the long steel cable material 4 are heated, and hot rolling is carried out by means such as a roll mill. A method for manufacturing stainless steel clad long steel characterized by crimping a pipe material onto the surface of a long steel material by rolling.