TW201323134A - Ultralow temperature high toughness austenitic welding rod - Google Patents

Abstract

An ultralow temperature high toughness austenitic welding rod comprises a welding core and a covering coated on an external wall of the welding core. The covering occupies 40-50% of the total weight of the ultralow temperature high toughness austenitic welding rod. By taking total weight of the covering as 100wt%, the covering comprises 25-40wt% of rutile, 1-4wt% of titanium dioxide, 3-12wt% of potassium-feldspar, 5-15wt% of mica, 5-15wt% of calcium carbonate, 3-8wt% of barium carbonate, 2-8wt% of calcium fluoride, 3-8wt% of sodium fluoride, 2-6wt% of electrolytic manganese, 5-12wt% of metallic chromium, 1-4wt% of metallic nickel, 1-4wt% of ferromolybdenum, and 0.01-1.50wt% of lanthanum oxide. By adopting welding of the invention, the mechanical property of deposited metal of welding seam is steady, particularly having excellent ultralow temperature impact toughness and thermal crack resistance. An ultralow temperature high toughness austenitic welding rod comprises a welding core and a covering coated on an external wall of the welding core. The covering occupies 40-50% of the total weight of the ultralow temperature high toughness austenitic welding rod. By taking total weight of the covering as 100wt%, the covering comprises 25-40wt% of rutile, 1-4wt% of titanium dioxide, 3-12wt% of potassium-feldspar, 5-15wt% of mica, 5-15wt% of calcium carbonate, 3-8wt% of barium carbonate, 2-8wt% of calcium fluoride, 3-8wt% of sodium fluoride, 2-6wt% of electrolytic manganese, 5-12wt% of metallic chromium, 1-4wt% of metallic nickel, 1-4wt% of ferromolybdenum, and 0.01-1.50wt% of lanthanum oxide. By adopting welding of the invention, the mechanical property of deposited metal of welding seam is steady, particularly having excellent ultralow temperature impact toughness and thermal crack resistance.

Description

Ultra-low temperature high toughness austenitic electrode

The present invention relates to an electrode, and more particularly to an ultra-low temperature, high toughness austenitic electrode.

In recent years, with the rapid development of industry, energy issues have become the focus of global attention. The energy on land has been exploited in large quantities. If energy is lacking, it will seriously restrict the development of industry and the improvement of people's quality of life. Therefore, countries around the world will target the exploitation of oil and natural gas in the ocean, so as to continuously provide stable Energy resources.

However, in order to develop marine resources, it is necessary to construct matching equipment, which is bound to involve a large number of piping systems, which must not only use excellent steel grades, but also must have excellent low temperature resistance and corrosion resistance, and pipe joints. The weld metal must also meet comparable mechanical properties, so the choice of weld material is especially important, in addition to the proper welding process.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an ultra-low temperature, high toughness austenitic electrode which is stable in mechanical properties of the formed weld, particularly having excellent ultra-low temperature impact toughness and thermal crack resistance.

The ultra-low temperature high toughness austenitic welding rod of the invention comprises a welding core and a coating coated on the outer wall of the welding core, the coating body occupies 40-50% of the total weight of the ultra-low temperature high toughness austenitic welding rod, The coating comprises the following components in terms of 100% by weight of the total weight of the coating: rutile: 25 to 40% by weight; titanium white powder: 1 to 4% by weight; potassium feldspar: 3 to 12% by weight; mica: 5 to 15% by weight %; calcium carbonate: 5 to 15 wt%; barium carbonate: 3 to 8 wt%; calcium fluoride: 2 to 8 wt%; sodium fluoride: 3 to 8 wt%; electrolytic manganese: 2 to 6 wt%; metal chromium: 5 to 12 wt% %; metallic nickel: 1 to 4 wt%; molybdenum iron: 1 to 4 wt%; and cerium oxide: 0.01 to 1.5 wt%.

The utility model has the advantages that the welding core adopts a low Cr-Ni-Mn type alloy system, and the coating body adopts a TiO ₂ -SiO ₂ -CaO slag system, and when the welding is performed, the arc is stable and the weld bead is beautifully formed. The utility model has the advantages of fine ripple, little splashing, easy slag removal, and AC/DC power supply, and is suitable for all-position welding. In particular, the formed weld has excellent ultra-low temperature impact toughness and thermal crack resistance.

The ultra-low temperature high toughness austenitic electrode of the present invention comprises a core and a coating applied to the outer wall of the core.

The core is a low Cr-Ni-Mn type alloy system, and the total weight of the core is 100% by weight, and the components (wt%) are as shown in [Table 1]:

The coating is made of TiO ₂ -SiO ₂ -CaO slag and accounts for 40-50% of the total weight of the ultra-low temperature high toughness austenitic electrode, and the total weight of the coating is 100% by weight, and the coating contains The components (wt%) are as shown in [Table 2]:

The composition (wt%) of the coating is preferably as shown in [Table 3]:

Specifically, the performance of each component of the present invention in a welding operation is as follows:

Rutile, its oxidizing property is relatively weak, the thermal slag removal property is good, the arc is stable, the molten pool is calm, and the metal transitions in a fine mist, which makes the weld bead beautiful, the slag coverage is complete, and the anti-porosity performance is good.

Titanium dioxide, the main function is to stabilize the arc, make the molten pool calm, less splash, good conductivity, easy to operate, can form short slag, has a significant effect on vertical and vertical welding, can produce lively slag, evenly covered The weld is protected by application, the slag removal is easy, the crystallization speed is fast, and the welding wave is fine.

Potassium feldspar, the main role is to stabilize the arc, slag formation, the right amount is conducive to slag removal, but the excess will slow down the welding speed and increase the viscosity of the slag, so the content of potassium feldspar is controlled between 3 ~ 9wt%.

Mica, the main role is to stabilize the arc, slag formation, and is flexible, which is conducive to the production of welding rods, can increase the permeability of the coating, so it has a preventive effect on the cracking and redness of the coating, but too much, too coarse mica will make the medicine The skin is loose, the electrode is easy to break the head and scratches, and the coating is too dry and rough, and the surface quality is poor, so the content of mica is controlled to be between 5 and 13 wt%.

Calcium carbonate and strontium carbonate are the same carbonates. Their main function is to slag and gas. The main purpose of slag formation is to protect the weld pool and improve the weld formation. The main purpose of gas generation is to Decomposes and releases gas to protect the arc and the molten pool from intrusion of oxygen and nitrogen from the surrounding air.

Calcium fluoride and sodium fluoride are both fluorides. Their main functions are slagging, dehydrogenation, viscosity adjustment, and improvement of slag coverage. However, the addition of fluoride will increase the amount of welding fumes.

Electrolytic manganese, the main role is deoxidation and transition alloying elements.

Metal chromium, metallic nickel and ferromolybdenum are mainly used as transitional alloying elements.

Cerium oxide, the main role is to refine the grains, change the shape, quantity and distribution of inclusions, thereby reducing its harmful effects on toughness and crack resistance, and also has a certain dehydrogenation ability.

Therefore, the ultra-low temperature high-toughness austenitic electrode of the present invention adopts a low-Cr-Ni-Mn type alloy system through the core, and the coating is performed by using a TiO ₂ -SiO ₂ -CaO slag system. The arc is stable, the weld is beautiful, the ripple is fine, the splash is very small, the slag is easy to remove, and the AC and DC power supply can be used, which is suitable for all-position welding. In particular, the formed weld has excellent ultra-low temperature impact toughness and thermal crack resistance. .

The invention is further illustrated by the following examples, but it should be understood that this embodiment is intended to be illustrative only and not to be construed as limiting.

<Example>

Examples 1 to 6 were manufactured by a manufacturing process common in the electrode production industry, in which the cores of the respective examples were prepared in accordance with the formulation components (wt%) shown in [Table 4], and in accordance with [Table 5 The formulation components (wt%) are formulated and blended by dry-mixing wet-mixing to prepare the coatings of the respective examples, and then the coating is applied to the core to form the ultra-low temperature of each embodiment. High toughness austenitic welding rod finished.

After the welding was used, the chemical composition (wt%) analysis results of the weld deposit metals of the respective examples are shown in [Table 6], and the mechanical property analysis results are shown in [Table 7], and the ferrite number test ( The results of the magnetic method are shown in [Table 8].

It can be seen from the above test results that the ultra-low temperature and high toughness austenitic electrode of the present invention has good mechanical properties of the deposited metal of the weld seam, and can obtain an impact value of 33 J or more at -196 ° C, and the excellent ultra-low temperature is apparent. Impact toughness; Moreover, the ferrite content of the deposited metal is strictly controlled between 3 and 5, which can reduce the brittleness due to ferrite, and can also absorb the impurity element through the ferrite to improve its thermal crack resistance. Furthermore, the addition of a small amount of cerium oxide to the coating can not only improve the strength and toughness by refining the grains, but also reduce the damage to toughness and crack resistance by changing the shape, number and distribution of inclusions. At the same time, the rare earth element La can increase the melting point of MnS and form a high melting point compound with S, which is beneficial to improve the thermal crack resistance of the deposited metal.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

Claims (3)

An ultra-low temperature high toughness austenitic electrode comprising a core and a coating applied to the outer wall of the core, the coating accounting for 40-50% of the total weight of the ultra-low temperature high toughness austenitic electrode The total weight of the coating is 100% by weight, and the coating comprises the following components: rutile: 25 to 40% by weight; titanium white powder: 1 to 4% by weight; potassium feldspar: 3 to 12% by weight; mica: 5 to 15% by weight; Calcium carbonate: 5 to 15 wt%; barium carbonate: 3 to 8 wt%; calcium fluoride: 2 to 8 wt%; sodium fluoride: 3 to 8 wt%; electrolytic manganese: 2 to 6 wt%; metal chromium: 5 to 12 wt%; Metal nickel: 1 to 4% by weight; ferromolybdenum: 1 to 4% by weight; and cerium oxide: 0.01 to 1.50% by weight. The ultra-low temperature high toughness austenitic electrode according to claim 1, wherein the coating comprises the following components: rutile: 28 to 35 wt%; titanium white powder, based on 100 wt% of the total weight of the coating : 1 to 4 wt%; potassium feldspar: 3 to 9 wt%; mica: 5 to 13 wt%; calcium carbonate: 5 to 10 wt%; barium carbonate: 3 to 8 wt%; calcium fluoride: 4 to 8 wt%; 3 to 8 wt%; electrolytic manganese: 2 to 6 wt%; metal chromium: 5 to 12 wt%; metallic nickel: 1 to 4 wt%; molybdenum iron: 1 to 4 wt%; and cerium oxide: 0.01 to 1.15 wt%. The ultra-low temperature high toughness austenitic electrode according to claim 1 or 2, wherein the core comprises the following components in terms of a total weight of the core: 100% by weight: carbon: 0.006 to 0.015 wt%; : 0.08 to 0.20 wt%; manganese: 1.80 to 2.25 wt%; chromium: 18.5 to 21.0 wt%; nickel: 9.0 to 10.0 wt%; phosphorus: 0.008 to 0.015 wt%; sulfur: 0.008 to 0.015 wt%; margin.