Preheat-free welding rod and manufacturing method and application thereof

Abstract

The invention discloses a preheat-free welding rod and application thereof. The preheat-free welding rod comprises a welding core and a coating and is characterized in that the coating comprises the following component in percentage by weight: 35-40% of marble, 2-5% of barium carbonate, 17-22% of fluorite, 0.5-2.0% of lithium fluoride, 2-5% of silica micro-powder, 4-6% of rutile, 3-5% of ferrosilicon, 2-4% of ferromanganese, 2-4% of ferromolybdenum, 1-2% of rare-earth ferrosilicon, 0.5-1% of sodium carbonate, 1-2% of magnesium powder, 2-4% of ferrotitanium, 8-10% of nickel powder, and the balance being iron powder. The preheat-free welding rod disclosed by the invention is specially used for welding a low-alloy high-strength steel in matched application, saves a preheat treatment in use, can remarkably reduce the content of diffusible hydrogen and the hardening capability of a welding material, reduces the number of welding cold cracks, and is of very important significance to simplification of a welding process, improvement of performances of a weld joint, reduction of production cost and improvement of working environment.

Description

technical field [0001] The invention relates to a non-preheating welding rod, a preparation method and application thereof, in particular to a matching non-preheating welding rod for low-alloy high-strength steel welding, and a preparation method and application thereof. Background technique [0002] Low alloy high strength steel has good weldability, excellent formability and low manufacturing cost, so it is widely used in pressure vessels, vehicles, bridges, construction, construction machinery, agricultural machinery, textile machinery, marine structures, ships It has become one of the most important structural materials in large and heavy welded structures. With the increase of steel alloying element content, strength level and welding structure restraint degree, its quenching tendency is obviously improved, and welding cold cracks are prone to occur. [0003] In production, pre-weld preheating and post-weld heat treatment are usually used to avoid the occurrence of wel...

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Problems solved by technology

[0003] In production, preheating before welding and heat treatment after welding are usually used to avoid welding cracks, which will bring about a series of problems such as complex production process, increased production cost, low production efficiency and deterioration of working environment, and will also increase The softening tendency of the welding heat-affected zone, in some special welding structures, it is difficult or even not allowed to preheat, which greatly limits the application of low-alloy high-strength steel