Flux core welding process for large-thickness ultrahigh-strength steel with yield strength of 690 MPa

Abstract

The invention discloses a flux core welding process for large-thickness ultrahigh-strength steel with the yield strength of 690 MPa. The end face of the ultrahigh-strength steel is provided with a groove angle of 25-50 degrees, the end face of a dissimilar high-strength steel forge piece is a straight face, and a proper root gap and a proper truncated edge are adopted; the pre-welding preheating temperature, namely, the cold crack resistance sensitive temperature, of the ultrahigh-strength steel is determined, and after the preheating temperature of the ultrahigh-strength steel is determined, a welded plate is integrally preheated; the two pieces of ultrahigh-strength steel are in butt joint, consumable electrode mixed gas shielded welding is adopted, and forward and reverse welding is conducted through a flux core wire; and after welding is completed, an electric heating sheet is immediately used for carrying out 200DEG C heat preservation. According to the process, the large-thickness ultrahigh-strength steel with the yield strength of 690 MPa can be welded, the welded large-thickness ultrahigh-strength steel with the yield strength of 690 MPa can be conveniently used at different positions, the optimized welding industry can be formulated by testing the preheating temperature of the large-thickness ultrahigh-strength steel with the yield strength of 690 MPa and designing reasonable welding industrial parameters, a high-quality welding seam is obtained, and the welding seam has excellent performance.

Description

technical field [0001] The invention relates to the field of welding industry, in particular to a flux-cored welding process for ultra-high-strength steel with a yield strength of 690 MPa in large thickness. Background technique [0002] Welding, also known as welding and welding, is a manufacturing process and technology for joining metals or other thermoplastic materials such as plastics by means of heating, high temperature or high pressure. Welding achieves the purpose of joining through the following three ways: 1. Fusion welding ——Heating the workpieces to be joined to make them partially melt to form a molten pool. After the molten pool is cooled and solidified, it can be joined. If necessary, fillers can be added to assist. It is suitable for welding of various metals and alloys without pressure; 2. Pressure welding - the welding process must exert pressure on the weldment, which belongs to the processing of various metal materials and some metal materials; 3. Brazin...

AI Technical Summary

Problems solved by technology

[0003] With the development of science and technology, more and more ultra-high-strength steels with a yield strength of 690MPa in large thicknesses are used more and more. Welding, but the existing welding process cannot effectively weld the large-thickness yield strength of 690MPa ultra-high-strength steel, it is easy to cause welding fracture, and the welding shape is not good. Therefore, we propose a large-thickness yield strength of 690MPa Flux-cored welding process for ultra-high-strength steel

Images