Welding process of low temperature steel welding body case

Abstract

The invention relates to a welding technique in equipment manufacture industry, which is a welding speciality technique of a welding casing of an MCL-typed horizontal cutting centrifugal compressor, in particular to a welding process of the welding casing of the centrifugal compressor with low-temperature steel 09MnNiDR material at -70 DEG C. The gas protection welding is adopted; the welding wire grade is HS09MnNiDR and the diameter of the welding wire is Phi1.2mm; the polarity of the power supply is reversed DC power. The invention comprises a processing before welding, a welding process and a processing after welding; wherein, the process parameters in the welding process are that the welding current ranges from 150A to 200A, the welding voltage ranges from 24V to 28V, the protection gas is the mixed gas with 80% of Ar and 20% of CO2 according to the volume percentage, the welding speed ranges from 250mm/min to 280mm/min, the dry elongation ranges from 10mm to 15mm, and the gas flux ranges from 20L/min to 25L/min. The welding wire of the gas protection welding of the invention is not required to be dried, the welding wire is automatically fed in the welding process, and a welding rod is not required to be replaced; as the heat of the MAG melting polar gas protection welding is concentrated, the invention has the advantages of narrow thermal effect area, little deformation, beautiful forming, good quality, low cost, fast welding speed, high welding efficiency, etc.

Description

Technical field: [0001] The invention relates to the welding technology in the equipment manufacturing industry, which is the welding professional technology of the welding casing of the MCL type horizontal split centrifugal compressor, specifically, the welding process of the welding casing of the centrifugal compressor made of -70°C low-temperature steel 09MnNiDR . Background technique: [0002] In the ammonia compressor unit of the chemical fertilizer oil conversion project and the ammonia ice unit project of synthetic ammonia transformation, the medium of the compressor is ammonia gas and ammonia ice, and the compressor operates at a low temperature. In order to meet the needs of the market, the welding casing material of the compressor 09MnNiDR (-70°C) low-temperature material is used. Whether it is this steel or welding material, it is the first time to apply it to the welding casing of the compressor. In order to ensure the successful welding of the welded casing of ...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the present invention is to provide a welding process for 09MnNiDR low-temperature (-70°C) steel welding casing, which solves problems such as welding deformation and welding efficiency, and uses MAG gas shielding with similar chemical composition and strength matching to the material of the welding casing Welding materials for welding can ensure the strength of the weld seam

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