SU876250A1 - Composition for making inserts used in locally alloying of castings - Google Patents

Description

The invention relates to ferrous metallurgy, in particular to foundry, and can be used in the manufacture of castings, working under conditions of abrasive abrasion for the manufacture of inserts and mounted in the mold cavity. The compositions of alloying materials and binder, applied to the surface of the DQ paint form are known. However, the inserted inside inserts completely dissolve when filled with liquid metal, alloying a certain (surrounding insert) metal volume, only slightly increase the wear resistance of the treated metal volume. This is due to the small amount of the alloying element passing into the metal surrounding the insert. Special paints applied to the surface form a metal layer to a depth of 1-2 mm or form wear-resistant burner with a thickness of 3-5 mm, which is unable to withstand abrasive abrasion to a great extent compared with the base metal. The closest to the proposed technical solution in terms of effect, effect and technical essence is the mixture for the manufacture of inserts used in local doping, including ferrochrome, water glass and expanded polystyrene at a given ratio of ingredients. However, this mixture does not provide high wear resistance of the working surface of the castings, and in addition, it has a high cost. The purpose of the invention is to increase the wear resistance of the working surface of the casting and reduce the cost of measurement. -38 The goal is achieved by the fact that the mixture additionally contains ash burners of steam generators and quartz sand with the following ratio of ingredients, wt.%: Styrofoam 1.5-5.0 Liquid glass 6.5-2.5 Ashes of furnaces. Steam generators40- 20 Quartz sand 20-10 Ferrochrome. . The rest Ferrochrome is used as an alloying alloy and has a size of fractions of 0.5-1.0 mm. He creates, in a complex with ash, furnaces of steam generators and quartz sand, the necessary wear resistance of a sintered conglomerate. The optimum amount of ferrochrome is 32-67% by weight. The amount of ferrochrome below 32% does not provide the necessary doping of the metal surrounding the insert rod. The amount of ferrochrome is the upper limit due to the non-caking of the mixture into the conglomerate, although bulk doping. metal is provided. (up to 3.4% chromium in the surrounding metal layers). The introduction of polystyrene is caused by the need to form cavities filled with metal in the insert rod during calcination. The optimal amount of expanded polystyrene is 1.5-5.0%. A larger amount of filler added negatively affects the strength of the core insert. Enter vzhzhigaemogo filler in an amount of less than 0.5%. does not ensure the formation of the required number of cavities filled with liquid metal. The ash of the steam generators' furnaces within 40–20 wt.% Provides the necessary sintering of the wear-resistant layer under the influence of high-temperature BI of the metal. The ash melting point according to GOST 2057-49 is 1175-1400C. Therefore, under the influence of liquid and crystallizing metal, this material softens and melts, binding the granules of ferrochrome and quartz sand into a single aggregate, which has high wear resistance under abrasive conditions. rubbing .. The ash content outside the claimed limits, as established experimentally, does not provide the necessary durability of the conglomerate due to the chipping of the granulometric components. Liquid glass is designed to provide the necessary strength of the cores. With the introduction of a significant total amount of 60% ash and quartz sand, up to 6.5% of the binder is injected, which completely ensures the necessary strength of the inserts. It is not economical to spend more binder. A binder in an amount below 2.5% does not provide a good insertion strength. The study of the suitability of the proposed composition of the mixture for the formation of an internal wear-resistant layer was carried out on castings of steel POG13L with the size of SOOGOCHbOO mm. In accordance with the proposed and known mixture compositions, core inserts 100 x X 100 mm in thickness 8.0 and 12.0 mm in molds were made to form a wear-resistant layer, blown with carbon dioxide and calcined in a heating furnace in 280-320 °. The insert rods were installed in the mold cavity at a distance of 10.0 mm from the surface of the α-form. The steel was poured at a temperature of 1,480 ° C. The blanks were riveted. Samples were cut out of the castings and the quality of the sintering layer and the relative wear resistance compared with steel From 3 under conditions of abrasive wear were determined. In tab. 1 and 2 shows the composition and properties of mixtures.

Table I

28 32 45 67 2.0 1.5 1.0 0.5 0.5 47 47 40 35 20

25 20 15 10

1.45, 5 "g / cm 6.5 4.0 2.5

Inserts are destroyed

Durable, caked

t

Durable, caked

Durable, caked

Fragile

Insert disappeared known

From the tables it follows that the highest wear resistance and durability of the wear-resistant sintered conglomerate is provided in the manufacture of inserts-rods of the mixtures of the claimed limits (Tables 1 and 2,

75 96.9

0.2 0.6 14.8

eight

2.0 2.5

table 2

8 12

2-5

4-5.5

8.5-9.5

8 12

10-11

8-9

8 12

9,5-11

8.3-9.5

8 12

10.5-11.5

2.5-3.5

eight

2.7-3.5 12

eight

5-6,5

compositions 2–5), in comparison with the compositions that go beyond the claimed limits (Tables 1 and 2, compositions 1.5).

Claims (3)

The insert, made of a known composition (Table 1, part 6), was completely dissolved. A wear-resistant layer with a chromium content of 3.1–3.4% was obtained in the doping site. The wear resistance of this layer is lower, by 1, times the wear resistance of the layer with this mixture of the claimed limits (Table 2, part 6). As follows from the table. 1, the addition of 2040% ash and 10-20% silica sand reduces the amount of ferrochro in the insert by 31-67% and, accordingly, the cost of the mixture will decrease by the indicated percentage rates. Claims of the Invention A mixture for the manufacture of inserts used in the local alloying of castings, including ferrochrome, water glass and polystyrene foam. This is due to the fact that, in order to increase the durability of the slave 8 whose surfaces of the castings, to reduce its cost, the mixture additionally contains ash from the steam generator fireboxes and quartz sand in the following ratio of ingredients, wt.%: 1.5-5, X) Liquid glass 6.5-2.5 Ashes of the furnaces of steam generators 40-20 Quartz sand 20- O Ferrochrome Else. Information sources taken into account during the examination 1. AN Bolotov. Investigation of local bulk alloying of steel castings. Abstract. -Dis. on the competition academic degree of candidate. tech. Sciences, 1974. 2. Cherkasov LN. Et al. Collection of papers of the Chelbinsk Polytechnic Institute, No. 155 1975, p. 182-187. 3.Bolotov A.N. - Foundry, 1965, No. 8, p. 33-34.