JPS58125385A - Manufacture of clad steel plate - Google Patents

Abstract

PURPOSE:To manufacture a clad steel plate having a different clad ratio in the same steel plate, by executing cladding by welding of different thickness to a stepped base material, and executing hot rolling. CONSTITUTION:A stepped base material 6 having different plate thickness T1 and T2 is manufactured by rolling or machine work, and thereafter, cladding by welding of a cladding material 4 is executed by use of this base material 6. As for the cladding by welding, any of submerged arc welding which uses a bandlike electrode, electroslag welding, etc. is available. The cladding by welding is executed as T1+t1=T2+t2 (provided that T1 and T2 are the thickness of the base material 6, and t1 and t2 are the thickness of cladding of the cladding material 4). Subsequently, a slab which has executed cladding by welding of different thickness to the base material is heated uniformly in a heating furnace, and thereafter, hot rolling is executed, by which a clad steel plate having a different clad ratio in the same steel plate is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a clad steel sheet, and more particularly to a method for manufacturing a clad steel sheet having different cladding ratios within the same steel sheet.

Conventionally, there are various methods for producing clad steel plates by hot rolling, but all of them are produced by hot rolling from a slab by an assembly method, a sensual welding method, an explosion bonding method, or the like. FIG. 1 shows a slab assembled by the assembly method, in which a laminate material 4 and a base material 6 are placed on both sides of a release material 2 at the center, and surrounding portions 8 are welded.

FIG. 2 shows a slab by the sensual welding method, in which a base material 6 and a mating material 4 are sensually welded. In both slabs, the cladding material 4 and the base material 6 are crimped together during hot rolling, but since the thicknesses of the base material 6 and the cladding material 4 are uniform, the cladding ratio of the clad steel plate after hot piezoelectricity is constant. Therefore, steel sheets having different cladding ratios within the same steel sheet cannot be obtained.

Demand for clad steel sheets has increased in recent years, and when used for cypress wood that requires corrosion resistance, the parts that are immersed in corrosive liquid and the parts that are not immersed are different from each other! Naturally, the depth of demand is different. However, if the entire structure is made of clad steel plate of the required thickness for the immersed part, the cost will be significantly higher. Alternatively, two different clad steel plates may be connected to each other, or the entire tank may be assembled using clad steel plates with the same cladding ratio, and then the required
There are methods such as overlaying the IGS portion, but all of them involve laborious work such as the welding process causing cracks and defects.

The object of the present invention is to solve the problems of the prior art described above.
An object of the present invention is to provide a method for manufacturing a clad steel plate having different cladding ratios within the steel plate.

The gist of the present invention is as follows.

That is, in a method for producing a clad steel sheet in which a laminated material is sensually welded to a base material and then subjected to hot air pressure, there are a step of processing the base material into different plate thicknesses in a stepped manner, and a step of processing the base material into different plate thicknesses in a stepwise manner, and a step of processing the base material into different plate thicknesses in a stepped manner. and the total thickness of the laminated material is the same throughout the slab (including a step of welding the laminated material overlay and a step of hot rolling the overlay welded slab, and the total thickness of the laminated material is different within the steel plate). This is a method for manufacturing a crud steel plate in which the crud ratio is determined as % mold.

In other words, the 35th! As shown in FIG. 4, a base material 6 having a different thickness T1 and a step shape of one layer is manufactured by rolling or machining, and then this base material 6 is used to form the thickness of a laminated material 4 as shown in FIG. Perform welding.

The build-up S* of this laminated material 4 can be done by any fj such as submerged 1-arc welding using a strip electrode or electroslag welding.
A single contact method may be used. Figure 4 shows a welding method using a strip-shaped electrode, in which while maintaining a constant thickness in the longitudinal direction of the weld line, the thickness can be changed stepwise by changing the number of contact baths in the width direction. It is something that In FIG. 4, Tl and Tt are the thicknesses of the base material 6, and tl and tt are the thicknesses of the laminate material 4.
The thickness is T > −) tt-T Yukiju is welded as if it were a goose.

In order to prevent defects such as slag entrainment when performing overlay welding near the step part, the shape of the step part of the base metal should have an angle θ of 100 or more with respect to the base metal surface as shown in Figure 3. is desirable.

Next, as shown in Fig. 4, slabs with different thickness welds on the base metal are uniformly heated in a heating furnace, and then hot-rolled to create a clad steel plate with different cladding ratios within the same steel plate. can be obtained.

By rolling the slab shown in FIG. 4 so that the overlay weld line direction is in the longitudinal direction of the steel plate, a two-sided steel plate having different crack and rad ratios in the width direction of the steel plate can be obtained. On the other hand, by rolling the steel plate so that the thickness and weld line directions are in one direction, a steel plate having different cladding ratios in the longitudinal direction of the copper plate can be obtained. Note that it is also possible to manufacture a steel plate having two or more cladding ratios within the same steel plate by increasing the number of steps according to IK.

EXAMPLE Using JIS 5841 as a raw material, a step-like slab with a thickness of 100 cm and 120 cm, a width of 1700 cm and a length of 3300 cm was manufactured by machining as shown in Fig. 5. The width Wr of the stairs and W snow were calculated as follows.

Base material width = 17001 = Shield + W intention (■) WtzLXn * 1 α - 300mX2 + 100m" - 70
0mWt=LXnt ten α-300mX3+100m-1
000m where L: overlay width...SOO■ ml, nl: number of overlay passes...respectively 2 and 3α:
Margin: 100 The base materials shown in Figure 5 are welded under the following conditions, and the stripes are 132cm thick, 150" wide, 150" long, and 300mm long as shown in Figure 6.
A 0 m slab was produced.

Welding conditions Welding height: 4 tm/Pass build-up width: 300 mI/Number of build-up layers in pass: 3 and 8 layer composite material JIS 5US304L The above slab was used in the same manner as a normal cladding arc to prevent grain boundary oxidation of stainless steel. The steel sheets were heated to a temperature that did not cause any cladding and were cross-rolled to form two-piece steel sheets. Thickness: 15cm
It was possible to produce a clad steel plate with a width of aooo mm and a length of 11,000 mm.

As is clear from the above embodiments, the present invention provides clad steel plates having different cladding ratios within the same steel plate by applying overlay #I of different thicknesses to the step-shaped base material and dissipating thermal pressure. could be manufactured.

[Brief explanation of the drawing]

Figure 1 is a side view showing the cladding slab according to the assembly method, #! Fig. 2 is a side view showing a conventional texture welded slab for clad steel, Fig. 5 is a perspective view showing a base material in an embodiment of the present invention, and Fig. 6 is a welded overlay slab in an embodiment of the present invention. FIG. 4... Lamination material 6... Base material agent Takeo Nakaji 1st I''71 2nd [1 3rd r!71

Claims (1)

[Claims] (1) In a method for manufacturing a clad steel plate in which the base material is welded to a base material and then hot rolled, the base material is processed into stepwise different thicknesses, and the surface of the processed base material is (
1. A method for producing a clad steel plate, comprising the steps of overlay welding a laminated material and hot rolling the inner S* slab, and having different cladding ratios within the same steel plate.