A high-nitrogen and low-nickel high-temperature flux-cored welding wire and its preparation process

Abstract

The invention provides a high-nitrogen, low-nickel, high-temperature flux-cored welding wire and a preparation process. The high-nitrogen, low-nickel, high-temperature flux-cored welding wire is composed of the following elements by mass percentage: C: below 0.04wt%, Si: below 0.8wt%, Mn: 0.5~5.0wt%, Cu: 1.0wt% or less, Ni: 25~33wt%, Cr: 17~26wt%, Mo: 3.0~6.0wt%, Nb: 3.0~5.0wt%, N: 0.1~0.4 wt%, Ti: 0.4~1.1wt%, Al: 0.1~0.5wt%, Ti / Al: 1.8~2.3 and Ti+Al: 0.5~1.5wt%, (Ti+Al) / N: 1.5~4.0, V : 0.04 to 0.12 wt%, Fe: the remainder. The invention adopts low-cost N to replace part of Ni elements, and prepares a new type of welding material used for welding 316L and part of nickel-based superalloys and whose high-temperature performance is not lower than that of nickel-based flux-cored welding wires, and simultaneously solves the problem of high price and scarcity of Ni. question. The high-nitrogen, low-nickel, and high-temperature flux-cored welding wire prepared by the invention can be used under high temperature (600-700° C.) conditions, and has excellent high-temperature mechanical properties, thermal crack resistance and high-temperature corrosion resistance.

Description

technical field [0001] The invention belongs to the field of welding in material processing engineering, and in particular relates to a high-nitrogen and low-nickel high-temperature flux-cored welding wire and a preparation process thereof. Background technique [0002] Nickel-based flux-cored welding consumables are used for repair welding of stainless steel with excellent high temperature resistance and corrosion resistance, and are widely used in various industrial fields. However, domestic nickel resources are scarce, and a large amount of imports are needed to maintain demand, which leads to increased costs and becomes a bottleneck for the development of the stainless steel industry. On the premise of ensuring the same performance and reducing the cost, finding new elements to replace nickel is the main development direction of industrial production at present. [0003] As a cheap resource, N element, similar to Ni element, has the ability to expand the austenite phase...

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Problems solved by technology

[0009] However, although the stainless steel flux-cored wire disclosed in Patent Document 1 uses the addition of N elements, the design concept does not focus on its substitution effect, and the flux-cored wire is designed to meet the impact performance requirements at extremely low temperatures, which is different from this Invention of flux-cored wire for high temperatures is different

In addition, although the flux-cored welding wire for high-temperature-resistant steel disclosed in Patent Document 2 can be used in an environment above 500 degrees Celsius, its high-temperature tensile strength cannot reach above 700 MPa, and the patented flux-cored welding wire has poor high-temperature corrosion resistance, which is different from that of The present invention adopts N to replace Ni with different design ideas, and the strength requirements achieved under high temperature conditions are different

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