High-nitrogen steel pressure welding device and method for welding high-nitrogen steel by using same

Abstract

The invention discloses a high-nitrogen steel pressurized welding device and a method for welding high-nitrogen steel by using the device, comprising an airtight welding chamber, a gas mixing chamber, and a vacuum pump; the airtight welding chamber communicates with the gas mixing chamber and the vacuum pump respectively through gas pipelines ;The airtight welding room is equipped with bracket, welding power supply, welding wire frame, wire feeding mechanism and welding torch; the cooling plate is arranged above the bracket; the welding wire sleeve is connected under the wire feeding mechanism; the welding power supply is connected with the welding wire sleeve and the bracket through electrode wires respectively The cold source is set in the cooling plate; the welding base metal is placed on the cooling plate; the raw material gas is mixed in the gas mixing chamber and then input into the airtight welding room; the position of the welding wire and the welding torch is adjusted, the welding power is turned on, and welding is carried out. By controlling the system shielding gas composition, system total pressure and cooling parameters, the nitrogen content in the high-nitrogen steel weld can be fixed, and the mechanical properties of the high-nitrogen steel weld can be improved. Using the system of the present invention for high-nitrogen steel welding, the nitrogen content of the weld can reach More than 95% of the base material.

Description

technical field [0001] The invention belongs to the technical field of welding metallurgy, and in particular relates to a pressure welding device suitable for high nitrogen steel and a method for welding high nitrogen steel with the device. Background technique [0002] High-nitrogen steel refers to the steel whose actual nitrogen content exceeds the limit value that can be achieved by preparing materials under normal pressure (0.1Mpa). It is a new type of engineering material developed with the advancement of metallurgical technology in recent years. According to the content of nitrogen in austenitic stainless steel, nitrogen-containing austenitic stainless steel can be divided into nitrogen control type ([N]=0.05%~0.10%) and medium nitrogen type ([N]=0.10%~0.40%) And high nitrogen type ([N] > 0.40%), while the nitrogen content in ferritic and martensitic stainless steel can be called high nitrogen steel as long as it is greater than 0.08%. [N] in high-nitrogen steel ac...

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Problems solved by technology

Although research results have shown that suitable laser welding conditions can avoid the loss of nitrogen and nitrogen pores in the weld zone of high-nitrogen steel, the microstructure and performance characteristics of the weld zone under laser welding conditions are still an important issue, and further research is needed.

For other fusion welding processes, the problem of nitrogen loss in the weld zone is still difficult to overcome. At the same time, quality defects such as welding cracks and nitride precipitation must also be considered.

At present, the conventional welding process suitable for high-nitrogen steel is carried out under normal pressure conditions. By increasing the nitrogen ratio in the welding shielding gas, it can play a role in fixing nitrogen in the molten pool to a certain extent, but the effect is not obvious, especially when the It is very difficult to increase the nitrogen content of the weld to more than 90% of the nitrogen content of the base metal

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