SU554974A1 - Electroslag Welding Device - Google Patents

Description

(54) DEVICE FOR ELECTRIC SLAG WELDING

one

The invention relates to a welding technique, in particular, to electric welding with regulation of thermal cycles.

A device for regulating thermal cycles during electroslag welding is known, which includes forming sliders and sets of basic nozzles attached to the bottom of the sliders with channels for feeding a cooling agent.

However, the known device does not allow an adjustable intensive heat removal from the heated metal only after it appears from under the slider during the secondary crystallization. In this connection, the thermal cycle can only be regulated at the cooling stage with a temperature of about 950 ° C. The consequence of this drawback is the inability to suppress the intensive growth and overheating of the austenite grain at the heating and cooling stages of the weld metal.

In addition, the known device does not allow zonal adjustment of the parameters of thermal welding cycles. This disadvantage is especially significant for heat strengthened steels.

In order to achieve the required structural-mechanical uniformity of welded joints, for example) when welding heat-strengthened steel of type 10G2FR, the cooling rate at the site of incomplete recrystallization (stretch) should be about 3 times higher than at the heat-affected area.

The purpose of the invention is to improve the quality of welded joints by ensuring the optimal parameters of thermal cycles of individual sections of the heat affected zone in the process of primary and secondary crystallization from temperatures close to the melting point.

Claims (2)

This is achieved by the fact that the proposed device is equipped with additional sets of nozzles installed on the side surfaces of the forming slider, and the working surface area of the additional and basic sets of nozzles is not less than the area bounded by isotherms with maximum temperatures close to the melting point, on the one hand, and Ac temperature or tempering temperature on the other hand, respectively, for structural-equilibrium or heat-treated steels. FIG. 1 shows the device, front view; in fig. 2 - the same, side view; in fig. 3 - the same, top view; in fig. 4 axonometric image of the device. The device is a set of slot-type nozzles 1 and 2 mounted on the side surfaces of the slider and behind the slider 3. Coolant through slots 4 enters the nozzle guide nozzle 5, the area 6 of the outlet of which defines the working surface of the nozzle. From this area, the cooling medium enters the product to be welded, providing cooling of the metal surface bounded by the Ac isotherm. The limitation of the cooling zone of the isotherm to the maximum temperatures corresponding to the critical point Ac and the tempering temperature is due to the fact that it is in the areas of the heat-affected zone with the maximum heating temperature in the range Tpl. - Ac. and m.p. - T tempering occurs the most unfavorable changes in the structure and properties of steels, normalized and thermally hardened, respectively. This is reflected in a decrease in the impact toughness of the heat-affected zone heated in the temperature range Tpl. —Ac, and in the loss of strength of the heat-affected zone, which is predominantly heated in the temperature range Ac, —Ac ACj- T of the base metal discharge. Equal strength of welded joints can be provided only under the condition that the working surface area of the nozzles is not less than the area limited by isotherms of the indicated temperatures. The device provides a differentiated supply of cooling agent in a separate section of the heat-affected zone during the welding process. Variable in the heat-affected zone, the intensity of cooling is created by supplying media 1 and 2 with different heat transfer coefficients to the nozzles 1 and 2. Thus, the conditions required for heat-treated steel of type 10G2FR can be provided, for example, when gas is supplied through nozzles 1, and through liquid nozzles 2 - through a liquid medium or due to the possibility of supplying water to nozzles 1 after preheating it while passing through channels Forming a slit ram. To this end, the coolant supply channels of the slider 7 and the nozzles 8 are connected, and to the side and bottom edges of the slider tides 9 are made with the channels 10, which supply the cooling medium from the slider to the nozzles 1. At the same time, these tides serve to attach the nozzle unit 1 and 2. Coolant is supplied to the nozzles by means of sleeves 11 (tubes) for water and air. Its consumption is recorded by special devices (for example, liquid flow meters, pressure gauges). The device for adjusting the parameters of thermal cycles begins to work simultaneously with the system of movement of the sliders on the product. During the entire welding process, the thermal cycle parameters are controlled. As a result of the application of the proposed device for ESW, it is possible to provide the specified, optimal for each specific area of the heat affected zone, parameters of the thermal welding cycles that contribute to the formation of structures with a favorable complex of mechanical properties. Claims The device for electro-slag welding, comprising forming sliders and sets of basic nozzles attached to the bottom of the sliders with channels for supplying a cooling agent, characterized in that, in order to improve the quality of welded joints by ensuring optimal parameters of thermal cycles of certain parts of the heat-affected zone the process of primary and secondary crystallization from temperatures close to the melting point, it is equipped with additional sets of nozzles, on the side surfaces forming slides; Moreover, the working surface area of additional and basic nozzle sets is not less than the area bounded by isotherms with maximum temperatures close to the melting point, on the one hand, and with the temperature of the end of structural transformations, on the other hand. 2 1 7 N Water 7 to hell / 1- / I II i II eleven -i eleven // / eleven eleven / IL -v J / FIG. five 9 s 13 2 6 r 11 eleven