JPS5954444A - Mold for continuous steel casting - Google Patents

Abstract

PURPOSE:To provide a casting mold for continuous casting of iron and steel having improved wear resistance, adhesive strengh, thermal durability, etc. and a long life by forming an electroless plating layer of an Ni-W-B alloy having a specific compsn. on the surface of the mold to be charged thereon with molten steel. CONSTITUTION:The area of a casting mold made of copper or a copper alloy except the surface to be charged thereon with molten steel is masked with a suitable covering material. Such mold is dipped in an electroless plating bath of an Ni-W-B alloy contg. 3-10wt% W and 0.3-3% B so that a plating layer of an Ni-W-B alloy of a desired thickness is formed. Alternately, the Ni-W-B alloy plating layer is formed after an underlying plating layer of Ni is formed on said surface. The plating thickness of the Ni-W-B alloy is set at about 5- 100mum and the plating thickness of Ni at about 200-2,000mum. The exposure of the copper in the mold for continuous casting of iron and steel is prevented for a long period of time by such covering layer and a billet having good quality is obtd.

Description

[Detailed description of the invention] (!Y1-i! Type # used for continuous machining of A-type alloy stone slabs, blooms, tubular slabs, etc.)
Generally, the material is copper or sigma alloy, which has good thermal conductivity. The bell-shaped inner surface (hereinafter simply referred to as the "mold inner surface") made of copper or silver alloy is usually entirely covered with a protective film to prevent it from coming into direct contact with molten steel or slabs. Then, the protective film is gradually worn away by casting. When the hook on the inner surface of the nail f-shape becomes exposed beyond a certain limit, the life of the mold is said to have come to an end. By preventing this tooth vg protrusion for as long as possible, fjf type fjf
Various protective coatings such as Ni plating layer and Cr plating layer have been proposed and put into practical use in order to extend the life of the product. However, none of these known protective films are satisfactory. For example, the Ni plating layer has a low hardness and is easily worn out. Therefore, if the thickness is increased for the purpose of extending the life, there is a problem that the thermal conductivity of 4i7 y4 will be lowered. Since the JCr plating layer has low hardness at high temperatures, it not only deteriorates to JI within a short period of time, but the cracks contained therein may even reach oxidation and peel off at high temperatures.

In view of the above-mentioned current situation, the inventor of the tree developed Ti1t (11
[As a result of repeated research, a nickel-based alloy containing specific amounts of 9, tungsten and Pounu ζ61] (and 6114 alloy 1 and +J exhibits extremely excellent properties as a coating for continuous mail 11 manufacturing molds) After discovering this, and conducting further experiments and research, I was finally able to complete the present invention.

That is, the present invention provides copper or paulownia alloy holding iron ε(・i 3 for continuous casting 4'l Jl; 17, 4'l for 11
31U of nickel-tungsten-boron alloy containing 3-10% tungsten and 08-3% boron, If;'% on the injection surface of the melt! The present invention relates to a samurai culm J for continuous casting of iron, characterized in that it has been formed with electrolytic plating.

Wood 'A light (n !!+',! Inner surface (D protective covering 1')
, 4! The N4 TalNiWB alloy layer has a melting point of approximately 1600°C, has poor heat resistance, maintains the highest hardness even at product temperatures, and has a thermal conductivity coefficient (high < fl) of linear expansion coefficient. It has a gender rating of 4.1, which is low.

Therefore, is it the solid side of glassy powder etc. between @7P7QJ and molten lead? In the usual method of use in which an IF agent is interposed so as to move along with the flow of molten steel, the excretion-receiving layer of the present invention exhibits excellent wear resistance, adhesion, and thermal machinability. As a result, its Xf-life is significantly extended.

In the present invention, N is formed by electroless plating.
W in the 1-W-n alloy layer is 3 to 15 njf44%, more preferably 4 to 87 ((j7i%. W content is 157FC) if: %, when the alloy Formation of the plating layer becomes difficult ν・11, while 8ff1t
, i+i% unAF: i F has insufficient wear resistance. Also, for B-seitame, 0.3 to 3 medium amount is also more preferable,
< is 0.5 to 2%.

B's i' fjl is 0.11:4. Ij! Ti
% rice white, the wear resistance tl is -1'i or insufficient, and -.
You can make 8 tons more money! rfpH:・jノ(
'l: There is a 1 (,) case that lowers 'l'. N
The thickness of the i-W-B alloy layer is Jl'll');i
' 5 to 100 m, amm hull 1, more preferably about 10 to 50 m. When the thickness is less than 5 μm, the protective film (') exhibits sufficient effect as a near layer.

If it is not obtained and rotates by 100 μm +,,L-, anti-membrane J1'; IiQ.

gradually becomes difficult, and cooling failure due to heat extraction failure 11 (
'There is a frB direction that produces J.

In addition, in the present invention, the bases 1 and 4 or (17 inner surface made of 1 and 4 alloy) are first coated by a known electrolytic plating method.
()0 to 20 (A Ni plating layer of about 10 μm is provided, and then a N1-W-n alloy plating layer is applied to the Ni plating layer-tx by electroless plating in 1/1. By setting the lifespan of gltf!411! to 11 years,
Rukoto can. In the case of this −nihi・) plating,
It is preferable that the Ni W Ti alloy plating is approximately 10 to 50 μD.

The Nl-W-n alloy plating layer in Invention Achievement 1□ was processed and plated at 11iJ according to a conventional method. It is formed by ψ action and line lλ・)ko. That is, 6ii11
Or (,1・)1 alloy (!・9. qBr,; Mask the part other than the welding surface of the mold with, for example, salt (I', a suitable material such as vinyl resin thread paint) θ; F11, Next, degreasing, activation by acid treatment, water 1if,
',! Let's do the 7th deletion. n；l Finished the pregnancy〈1
Taking one example from Table 1 C, the electroless plating bath with the composition shown in iU )+'f L, II 2S04, N 1
140 HζIt, due to j white l) H from 65 to 69
While maintaining the swamp temperature at about 60 to 65°C, perform gentle mechanical plating operation. When plating, Pl depth is 80 μm (7) Ni-W-n alloy plating (W 57i-<-r:1)% and B1 weight ■
i) Form %) Z) F for 6 mouths, '-15 hours.

Table 1 Note that the bath compositions not shown in Table 1 are merely examples that can be used to form the alloy plating layer of the present invention, and can be changed according to the phase law of the alloy composition. Needless to say, it will happen.

Example 1 A Nl plating layer and thickness of 1000 μm on the short side (250 mm inside x 7 (10 mm) height contact surface of the molten metal) of a deoxidized copper slab continuous casting mold containing 1wt% silver Sa80
ttm's N1-W (5 claws EIl'c 1-) B
An alloy plating layer of (1 electric I, 1%) was formed on the 18+th stage.

The obtained mold was heated at a UJ loading speed of 0-8 m/mln.
When used for casting the lJ jjf+ example, it turned out to be 625g.
There were no abnormalities such as the addition of 1 yen on the back cover of the yage, and the surface quality of one piece was as good as 4jff, so it was possible to continue the 11th construction.

Example 2 A 1000 μm thick Ni plating layer and a 80 μm thick Ni plating layer were applied to the melting contact surface of the long side (medium 2400 mm, base height 700 mm) of a deoxidized copper slab continuous casting mold containing 1 iT [i% silver].
/1m of Ni W (5!RM%) -B (1 electric rating%
) alloy plating layers were sequentially formed.

When the obtained mold was used for continuous casting in the same manner as in Example 1, no abnormality was found in the 812 charger, and the surface quality of the slab was (1) (extremely good). , it was possible to continue the sabotage further 111'.

Comparative Example 1 Molten edge of mold similar to Example 2 ω〉A contact 1 Thickness 1 on side
A N1 plating layer of 00 G/lnl and a Cr plating layer of 80 itm were formed.

Using this mold, the same number of j1 as in Example 1 was obtained! t
When it was used in +'5tit construction, the plating layer was severely worn out after 480 yards, and 111 pieces were unusable.

(Hereafter) Procedural amendment written (spontaneous) Commissioner of the Patent Office Nagisa 1'/vll,,ls Tono 1, Indication of the case 1982 Patent application No. 153308 2/R
l'J] +7) Name Steel, Uμ continuous casting bird,
Go to 1. 3. Person who makes the correction
・, New 11 Wooden Claw Stock Association, , i/
(1 other person) (652D Patent attorney Eiji Saegusa 5, L1 of the amendment order) Self-initiated 6 Number of inventions increased by amendment (1) lli Contents l R'tod of the specification 8 'I' Scope of Claims' in attached sheet (7)
) imsu J1 correct.

2. Specification C4, line 5 of 51L, which says, ``It is possible to extend it further.'' I have revised it as follows.

"It can be further extended. Therefore-C1 The present invention can be extended further.
Confucian t-alloy steel is 1! For continuous casting The present invention also provides an iron C-1 continuous casting mold characterized in that an electroless plating layer of a metal alloy is repeatedly formed. ” 3 Specification No. 8V1: 11th shot F became unusable. ”
Correct the statement as follows.

"It has become unusable.

Example 3 A molten steel contact surface on the short side (width 250 ff N x height 700 mm) of a slab continuous casting mold made of deoxidized copper containing 1 weight 1 weight % silver was coated with a thickness of 50/Z m (7) Ni − 1r'(
An alloy plating layer of 5%)-ZJ(1%) was formed.

Cast the obtained mold? Li degree Q, 3 rn/m
I was used for casting in May, and when continuous casting was performed up to 161 charges, copper exposure was only observed on the mold surface at the lower end of both the left and right sides with a distance of about 30 mm and a height of about 70 rm. No particular abnormality was observed.

Comparative Example 2 #i-W-B A Cr plated layer was prepared in the same manner as in Example 3 except that a Cr plated layer was formed instead of the alloy plated layer.
A mold coated with a plating layer was obtained.

When this mold was used in a mold for ordinary steel at a casting speed Q of 8 m/min, a height of about 60 feathers was formed on the entire lower end of the mold surface (approximately 110 fl on both left and right ends) at 85 cm.
) copper exposure was observed.

Example 4 (Deoxidized copper-plated slab containing 141 weight ff, t%) Bath 1 was applied to the short side (1250 mN x height 700 mN) of the molten steel contacting surface of the mold for continuous VJ production in a bath having the following composition. crystal 55°C1'
Electrolyzed for 25 hours at a flow density of 2A/dm'' to remove hard nickel plating with a hardness of 530.
00μm thick, h0chida1, nilyl sulfate
+8oy/l Chloride:)℃ Chive 1. 259/17 boric acid
30 d/e Small amount of additive Nail hardness above 4.゛l On the nickel plating layer, carry out t! II
Thickness 50 p pn no N1-rv (5 layers 1
','4)-B (1% by weight) alloy plating layer was formed.

Using the obtained mold, continuous casting was carried out at [-7] up to 610" f-sage in the same manner as in Example 1.
1: There was no 1, and the surface quality of the slab was 1 electric light. (Hereinafter referred to as J2) 2. Claims (W) A casting mold for continuous fIf production of rust or copper alloy 17 steel, containing 3 to 10 heavy percent of steel and 0.3 to 0.3 to 10% of boron on the molten steel injection surface of the mold. Electroless plating layer of di-soliutane cystine-boro alloy containing 3% by weight ・11
・A type for steel continuous SII Zokawa button with ↑, de sign that it was made.

Angle −ζ−,! The child who has the li rank is the parent - Iwazato Jun - Takeshi.

Claims (1)

[Claims] ■ Qingang Lianhong made of copper or copper alloy;
8~10m9t% of tungsten on the ch type molten steel injection surface
A base cast base for producing a pJ layer continuous G, characterized in that an f1Mm deplated layer of a nickel-tungsten-boron alloy containing 0.3 to 8 weight % of boron is formed.