Aluminum-steel heat release welding method

Abstract

The invention discloses an aluminum-steel heat release welding method. The method comprises the steps that to-be-welded sections of an aluminum block and a steel block are polished cleanly; a pre-polished steel sheet is placed to cling to the aluminum block between a gap of the to-be-welded sections of the aluminum block and the steel block; a bottom through hole of a graphite crucible is aligned to the center of the gap; a self-propagating welding flux is put into the graphite crucible; pyrophoric powder on the surface of the self-propagating welding flux is ignited; molten liquid generated by self-propagating welding flux reaction flows into the gap between the aluminum block and the steel block from the bottom small hole of the graphite crucible; the steel sheet is heated, molten, and cooled to a room temperature; and then aluminum-steel welding is accomplished. The adopted self-propagating welding flux comprises the following raw materials by mass percent: 22-28% of Al powder, 62-68% of Fe2O3 powder, 4-7% of Si powder and 3-6% of slag forming constituent. The method is simple to operate, simple in equipment, stable, safe and reliable in reaction, extensive in raw material, low in cost and less in joint slag inclusion, and has a great industrial popularization value; aluminum steel bonding adopts metallurgical bonding; and the quality is good.

Description

[0001] technical field [0002] The invention belongs to the technical field of material processing and manufacturing, and in particular relates to an aluminum-steel exothermic welding method. Background technique [0003] As a silver-white light metal, aluminum has excellent ductility and is also the most abundant metal element in the earth's crust, so it has important development prospects in the fields of aviation, construction, and automobiles. Due to its low price and reliable performance, steel has become one of the most used materials and is an indispensable component in construction, manufacturing and people's lives. Combining the excellent properties and application prospects of aluminum and steel, welding between aluminum and steel dissimilar materials has naturally become a hot spot. However, due to the very different properties of aluminum and steel, the melting point is very different, so it faces great technical challenges in actual welding. [0004] At prese...

AI Technical Summary

Problems solved by technology

Due to the very different thermophysical properties of aluminum and steel, the solid solubility is low, and intermetallic compounds are easily formed while forming alloys, which leads to the performance degradation of aluminum-steel welded joints, and whether the formed welded joints are mechanically bonded or There is no strong experimental explanation on the issue of metallurgical bonding

Therefore, in order to improve the strength of the aluminum-steel welding street, the welding process must be improved. The practice of pre-preparing a layer of aluminum on the steel surface in patent 200910072270.2 does reduce the generation of interfacial compounds and improve the quality of welding to a certain extent, but The welding method of this method uses MIG welding, which does not control the cost

In patent 201310367501.9, a layer of aluminum is covered on the surface of steel by hot-dip aluminum to realize the metallurgical bonding of aluminum-steel self-propagating welding, but the formula used in this method contains SnO 2 and Cu 2 The economy of O is not high, and the cost is not controlled

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