SU1389963A1 - Method of arc welding parts made of carbon steel and parts made of high-alloyed austenitic steel - Google Patents

Abstract

This invention relates to the welding of joints from dissimilar metals. mainly arrows and crosses from high-manganese-casting with carbon steel rail. The purpose of the invention is to improve the quality of the welded joint. This is achieved by treating the end of a cast product by grinding its end across the entire cross section, followed by surfacing the facing layer on it. The cladding is carried out with an OZL-19 electrode with a coating composition of rutile-base type and a core of nickel-chromium wire containing 25% chromium and 13% nickel. The ends of the blanks are welded with a manganese electrode of the Scientific Research Institute-48G with a wire rod containing alloying elements - 20% chromium, 10% nickel and 6% manganese, and a coating of the main type. The OZL-19 electrode provides the minimum heat input to the 110G13L metal, which is prone to cracking when overheated. 2 tab. 3 cl

Description

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The invention relates to welding, in particular, to methods for producing joining structures of dissimilar metals, preferably tram metals. arrows and crosses of manganese cast with carbon steel tram rails.

The aim of the invention is to improve the quality of the welded joint. Yu

The joint consists of a casting part, for example, an arrow or a cross, made of cast 110G13L manganese steel, and a tramway made of rolled steel, 15 M-75 steel. Steel 110G13L in comparison with carbon steel has a low thermal conductivity and a large linear expansion coefficient. When welding in the arc bath method in result-20

a large heat input in the case of

the contact of dissimilar metals in the welded edges of the casting will result in large temperature stresses with significant development of the base metal and its structural changes, and consequently, a decrease in the strength and strength characteristics of the weld. With the proposed method of welding

forms throughout the cross section of the joint. The electrode has a rod of steel 10x20N10G6S.

Welding the main section with electrodes of the NII-48G grade, which have the necessary plastic properties and close values of the expansion coefficient with respect to the OZL-19 electrodes, ensures good weldability along the fusion boundaries of two types of electrodes and good weldability with carbon steel M -75 of which the tram rail is made.

Welding of high-manganese austenitic steels is usually associated with low technological strength due to the formation of hot cracks in the weld metal and the transition zone.

High manganese steel 110G13L has the highest tendency to crack formation in the near-weld zone, which refers to the discharge of particularly difficult to weld steels.

In the process of welding, unlike other steel grades, under the influence of

dissimilar steels, in particular the stre-ep welding cycle in the thermal zone

the effect is the formation of a liquid phase of the eutectic composition, consisting of carbides and phosphides of the Stagit type, located along the boundaries of large austenite grains.

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The lock or cruciform of high-manganese steel with a carbon rail is manufactured as follows. Before welding the dp of the cast rind from the end of the cast part, it is ground to a depth of 2-3 mm. After stripping, a facing (blocking) layer 4 mm thick with OZL-19 electrodes of rutile-base type with a diameter of 4 mm is applied to the end of the cast billet. followed by its grinding (elimination of irregularities), electrode rod Made of steel 10x24N13G2.

Applying the cladding layer with OZL-19 grade electrodes, as shown. metallographic research provides the minimum heat input compared with other types of electrodes of this type, contributes to the minimum formation of a liquid eutectic component at the boundaries of austenitic grain and, thus, reduces the tendency to the formation of hot cracks along the border: with melting on the 110G13L steel side.

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the effect is the formation of a liquid phase of the eutectic composition, consisting of carbides and phosphides of the Stagit type, located along the boundaries of large austenite grains.

The low thermal conductivity of steel 110G13L in combination with a very large coefficient of linear expansion and large shrinkage (1.5-1.8 times more than that of carbon steel) cause extremely high thermal stresses, which contribute to the formation of hot cracks. Therefore, high-quality welding of steel 1 YG 13l can be ensured only under the condition of minimal heat input and appropriate welding technology.

The smallest heat input is provided by using electrodes of the OZL-19 brand, which have an insignificant melting capacity.

At the same time, it is not welding the whole cross-section or joint, but a pre-layer welding of the facing layer of the joint,

Welding of the main cross section of the joint reduces the occurrence of inside the electrodes of the NII-48G brand with the main type being coated by an arc bathing method using copper

early stress. Thus, the use of a facing layer in this case is necessary, since

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influences, a liquid phase of the eutectic composition is formed, consisting of carbides and phosphides of the Stagit type, located along the boundaries of large austenite grains.

The low thermal conductivity of steel 110G13L in combination with a very large coefficient of linear expansion and large shrinkage (1.5-1.8 times more than that of carbon steel) cause extremely high thermal stresses, which contribute to the formation of hot cracks. Therefore, high-quality welding of steel 1 YG 13l can be ensured only under the condition of minimal heat input and appropriate welding technology.

The smallest heat input is provided by using electrodes of the OZL-19 brand, which have an insignificant melting capacity.

At the same time, it is not welding the entire cross section of the joint, but the pre-layer welding of the facing layer of the joint,

early stress. Thus, the use of a facing layer in this case is necessary because it contributes to the increase in the strength of the welded joint.

For welding the main section, electrodes of the NII-48G brand are used. A booster of such a brand of electrodes is explained by the high technological strength of the weld metal due to the optimal composition of the steel composition (Fe, Cr, Ni, Mn,

C), which ensures a good relaxation of internal stresses, and the positive effect of manganese on the diffusion process of migration of harmful impurities at the austenitic zone. The chemical composition of the deposited 15 etall with austenitoferritic structure of the electrodes used is given

Table 1.

A prerequisite for high quality. The welding of carbon rails and 20 high manganese products is the setting of an optimal gap between the products to be welded within 12-14 mm, which ensures minimum heat input and the possibility of good penetration.

With gaps less than 12 mm, it is difficult to manipulate the electrode, which leads to the formation of fusion. In gaps of more than 14 mm as a result of 30 significant heat input, increase the arc seam welding method of high-manganese joints with carbon rails using NII-48G grade carbon

The tendency of the weld to hot cracks.

The test results of welded rail joints for static strength are given in Table 2.

F o rmula of the invention

The method of arc welding of carbon steel parts with parts of high-alloyed austenitic steel, in which the edges of one of the parts being welded are pre-welded and subsequently welded with electrodes with a high austeness margin, characterized in that welding of arrows and crosspieces from cast high-manganese steel with a rail of carbon steel, grinding of the end of the cast high-manganese part and surfacing of its OZL-19 electrode with It is made of rutile-base type and a rod of chromium-nickel steel, and subsequent welding of parts is carried out using III-48G electrodes with a base type coating and the core is made of chromium-nickel-iron steel using a copper method.

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Tja b. l and c a 1

T and yes 2

40-50

51389963

Prolongation table.2

Arc-arc welding method of high-manganese joints casting with carbon-railed OZL-6 electrodes without applying a facing layer

Arc welding method with the application of a facing layer with OZL-19 type electrodes and welding of the whole section. the joint electrode brand NII-48G

12-14 40-60

15-20 80-100

Claims (1)

Claim A method of arc welding of carbon steel parts with parts of high alloy austenitic steel, in which the edges of one of the parts to be welded are pre-welded and subsequently welded with electrodes with a high austenitic margin, characterized in that, in order to improve the quality of the welded joint, when welding arrows and crosses from cast high-manganese steel with a rail made of carbon steel, grinding is carried out, the ends of the cast high-manganese parts and surfacing it with an electrode of the OZL-19 brand coated with of the base type and the rod made of chromium-nickel steel, and the subsequent welding of the parts is carried out with NII-48G electrodes coated with the main type and the rod · made of the nickel-chromium-nickel steel alloy by the van30 method using copper molds. Electrode mark _ _Т_ ^ а_б ^ _л_и_ц_а __] _ The chemical composition of the weld metal,% OZL-19 NII-48G 0.09 1.4 0.43 23,4 13,20 0.10 5.9 0.6 19.6 9.7 Table 2 Type of welding Deflection arrow, mm Static load, tf 1 2 3 Arc suture method of welding joints of high-manganese castings with carbon rails with carbon NII-48G 1 40-50 Continuation of Table 2 1 I I T- 2> Arc bath method for welding high-manganese casting joints with carbon rails with 03L-6 grade electrodes without applying a facing layer 12-14 40-60 Arc welding method with applying a facing layer with electrodes of the OZD-19 brand and welding the entire section. junction with electrodes of the brand NII-48G 15-20 80-100