DE1758781C3 - Process for the production of unquenched cast steel blocks in rectangular molds - Google Patents

Description

• The heat insulating material for the procedure According to the invention used molding consists of a fine-grained heat-resistant or refractory material, an organic or inorganic binder and / or an organic fibrous material including a porous material and / or a heat-resistant one low fiber material.

As fine-grained, heat-resistant material, for example, quartz, SiO ₂ or materials with a content of more than 90% SiO ₂ , brick powder with a high aluminum oxide content, burnt magnesium oxide, periododite, aluminum oxide, corundum, expanded slate, perlite and lapilli are used.

Thermosetting synthetic resins and water glass are used as organic or inorganic binders used.

As organic fiber-like materials or porous materials, for example cellulose, waste paper, materials containing cellulose fibers, pulp, it. uses hammered paper, coke powder and flour.

As heat-resistant fibrous materials are for example asbestos, rock wool, inorganic fibers, mineral wool and glass wool are used.

The above components for the heat insulating material can be, for example, in the following Quantity ranges are mixed with one another:

1. 75 to 90 percent by weight of one or more substances from the group silicon oxide, quartz or materials with a content of more than 90% SiO ₂ , less than 15 percent by weight paper pulp or paper waste. 5 to 18 percent by weight thermosetting synthetic resins or water glass and less than 3 percent by weight asbestos, mineral wool, rock wool or glass wool.

2. 85 to 95 percent by weight of one or more substances from the group of brick powder with high Aluminum oxide content, burnt magnesium oxide, periodotite, aluminum oxide or corundum, and 5 to 15 percent by weight of a thermosetting resin or water glass.

3. 85 to 95 percent by weight of one or more substances from the group of expanded pine, perlite, or Lapilli, less than 15 percent by weight of one or more coke powder, sawdust, cereals or their powder, 5 to 18 percent by weight of thermosetting synthetic resin or water glass, and less than 3 percent by weight asbestos, mineral wool, rock wool or glass wool.

In the case of the mixtures given above, the fittings should preferably have the following properties:

Mixtures specific weight
(in g / cm ^s ) porosity
(%) 1
2
3 0.85 to 0.96
1.2 to 1.6
0.8 to 0.9 45 to 60
35 to 40
40 to 60

The advantages of the method according to the invention are illustrated in the following example.

example

7 two opposite side surfaces of a mold were completely made to a thickness of 20 mm lined with a heat-insulating material, on the long sides up to 100 mm below the upper edge of the mold. The heat insulating material used for this consisted of 50 percent by weight Brick powder with a high alumina content (with an average grain size of less than 0.5 mm) 42 percent by weight corundum (with an average grain size of less than 0.5 mm) and 8 percent by weight Binder (water glass). The specific weight was 1.45 and the porosity 35.8 "0-der Block of uneasy cast steel (with 0.13% carbon and 0.36% manganese) was poured into place of steel made from below The following table lists the properties of a ingot produced by the method according to the invention and one produced in a conventional manner Compared to the cast ingot.

Distance (in mm) Thickness of the firm skin (in mm) InventLingsgemäfiiVj Pipe- According to the invention from the top from the mold wall proceedings shaped gas inclusions proceedings of the ingot measured 125 none Conventional light 98 Conventional ke.-ne 100 proceedings 60 proceedings none upper part 150 275 49 none none 200 210 31 none none 250 164 28 none none 500 127 30th none none 750 48 31 none very little 1000 37 47 very little little 1250 38 lots little 1500 53 lots little 1750 69 lots 1900 -. lots Lower part - lots

For this purpose 4 sheets of drawings

Claims (1)

to be affected by that the block head Jach kept peeling off the mold hot claim: ⁿⁱ r " Piir Hie experts have so far taken it for granted A method of "Create-effervescent vergösse- ™ ^{r 01} J"'"i _{Erzie ung} a quenching ner steel blocks into rectangular molds, Toggle ⁵ ^ ₁ J ^m * .." J ^"r _W ärmeübergangsverhältnissezwischen by in that two ^^ ^ X , ™ steel and the walls of the opposite side surfaces of the code ß »oizη π ^^ _t ^ ^ kill completely with Wärmeisoherendem Ma- ^. £ Prejudice against the use of a be lined material. heat-resistant material was present. The proposed cover shells should only protect the radiation serve to protect. The invention was therefore the task based on creating unquenched cast steel blocks with a uniform cast skin and the gas It is known that with calm cast steel, 5 included in the outer zone to a large extent adorn both the mold head and the whole mold. . _{This could now be} determined who completely or partially with ^{thermal insulation "1} JfSEJ ^ use of a thermal insulation Materials to be lined. It is also the fact that oer y ™; ' . *. Material is a well known that when casting unkilled layer of a warm-shear materal erne steel during solidification within the mold *> solid cast skin f ^'CHF ° ^rm ^ ^r £ St one dtduren a significant Voä-.men of carbon monoxide gas overall low Strong: possesses ^ This is achieved by forming. A portion of this gas is during that solidification de de wd * meisoh walls solidification ^ molten state included liner contacting gesch _m0, ene, steel _he -. And forms so-called voids. The rest of the gas hesitates by preventing the steel from escaping from the molten steel into the atmosphere a ₅ heat suddenly on dm ^Ιη " ^βη ^" ^α ^ " _β ^ ° _η ^Γηι , ^. Some of these voids within the steel Furthermore, it was possible to: it was possible to compensate for the shrinkage of the unsteady cast steel blocks occurring in the unaffected cast steel cam, so that the cavities or voids which occur in an advantageous manner when shrinking can be avoided if the In this way a high level of the mold is influenced by the fact that the warm yield when casting unsmoothed insulating lining over the entire area of steel blocks, namely at low cost, two opposite one another Se.flatcn of the costly form covered. The calibrated according to known methods The invention therefore relates to a method for However, cast steel blocks have the disadvantage of producing unquenched cast steel blocks in on that the solid cast skin, in contrast to the rectangular mold, which is characterized impure steel in the middle of the block is a layer that has two opposite sides made of represents unquenched cast steel and the surfaces of the molds are completely covered with warm.sol.erene unevenly Thickness is. At the same time occur in the material to be lined. . . . Outer zone with primary cavities and segregations. 4 ° In the following description some important The thickness of the solid cast skin comprises those preferred embodiments of the method Area of the outer zone in which no voids of the invention on the basis of the drawings in detail available. A thickness of explained is considered to be optimal. 25 to 35 mm. The thickness in the upper part of a fig. 1 shows a side sectional view of a According to the usual method, the rectangular mold according to the invention for the cast steel block is usually several places of unconsolidated steel blocks:
hundred mm, while the thickness in the lower area F i g. Fig. 2 is a top plan view of that in Fig. 1g. 1 cedes block is about 10 mm. An unevenly pointed mold; moderate thickness of the solid cast skin has a negative effect on F i g. 3 is a graph showing the on the rolled steel, and this in particular, curve A represents the thickness of the cast skin, which means when it is sheet steel. the method according to the invention is obtained In the manufacture of unquenched cast steel while the curve B is the thickness of the cast skin, there was previously a prejudice against the lining, which is achieved by means of the known method of the molds with heat-insulating material. In which will; German patent specification 577 693 is, for example, 55 F i g. 4 shows the tubular gas inclusions in FIG a method and a mold for improving the block cross-section as used in the known processors described by unquenched cast steel that occur; is characterized in that the mold above F i g. 5 shows the tubular gas inclusions in FIG as a radiation protection a conclusion with bad block cross-section as in the method according to de thermally conductive inner surface. The present with a 60 invention. thermal insulating material lined heat- When performing the method according to de hoods in the upper area of the steel block, the invention is as shown in FIGS. 1 and 2 shown Temperatures during solidification on a molded piece 2 made of heat-insulating material ai Keep the elevated level in order in this way the two opposite side surfaces: Avoid the presence of shrink-wrinkles / u. Arranged in the 65 of a mold 1. The fittings au German patent specification 608 556 is a process the heat insulating material can also age described, in which the elimination of deoxinative is arranged on the side surfaces 4 of the mold 1 dation slag from the liquid block core.