Characteristics

CrN63Mb (EP758U) chromium-nickel steel is melted by open induction method. It is used for the production of welded chemical equipment (pulp and paper, chemical, petrochemical industry and in pollution control systems). The alloy withstands the action of particularly aggressive media containing fluorides, chlorides, organic acids, heavily contaminated mineral acids, complex acid mixtures, chemicals at elevated temperatures (above 100°C). It is used in the production of synthetic rubber, compound fertilizers, acetic acid, acetic anhydride at t° from -70 to 500 °C, and a pressure of no more than 5 N/mm². The following specifications are provided for the alloy: 14-1-4202-87; 14-3-1478-87; 14-1-4289-87; 14-131-755-85; 14-1-4734-89; 14-1-4881-90.

Chemical composition

Mechanical properties at 20 °С

Mechanical properties of sheets 10 mm thick, quenched in water at t ° 1070 ° C

Mechanical properties at high temperature (90 mm bars, hardening process with 1100 °C in water)

Mechanical properties at 20 °C, depending on the degree of cold-plate deformation (wires Ø 1.5-3 mm, water hardening process before deformation from 1100 °C)

Physical properties at 20°C

The alloy has a density of 8.9 g/cm3; specific electrical resistance is 1.75 Ohmxmm2/m; specific heat capacity = 392 Joule K); thermal conductivity is 0.096x10² W (Dm-K); magnetic permeability ≤1.001; modulus of elasticity = 20x10-4 N/mm2. The values of the temperature coefficient of linear expansion α

Corrosion resistance

According to TU 14-3-1478-87, 14-131-755-85, 14-1-4289-87 and 14-1-4202-87, 14-1-4881-90 this alloy must be resistant to intergranular corrosion after provoking tempering at t° 800 °C (30 minutes). These tests are carried out in a boiling 30% H2SO4 solution with 40 g/l FeSO4 (48 hours) or in a boiling 50% H2SO4 solution with 40 g/l (18 hours). Welded joints are characterized by resistance to intergranular corrosion. In the quenched state, the alloy is resistant to pitting corrosion in 10% chloride iron as well as to corrosion cracking in 42% boiling MgCl2.

The alloy is resistant to corrosion in aggressive media:

• in solutions of inorganic acid salts (ammonium chloride, aluminum chloride, ferric chloride, iron sulfate, calcium chloride, etc.);
• in aqueous solutions of copper and iron chlorides, chloric acid, chloro-sulphonic acid and hypochlorous acid;
• In dry and wet chlorine;
• in sulfuric acid from 20 to 98% the alloy is very resistant (Vcor ≤ 0.1 mm/year) at 90°C;
• in mineral acids (phosphoric, nitric, hydrochloric, sulfuric) contaminated with fluorides and chlorides;
• in strongly oxidizing mixtures of acids and chemicals;
• organic acids (acetic, formic, oleic acids).

Technological properties

The alloy can be cold and hot deformed by almost all methods of forming. The temperature range of hot deformation = 1220-950°C. The heat treatment is carried out at 1100+20°C (3-5 minutes/mm exposure) with quenching in water or accelerated in the air. Due to the tendency of the alloy to sticking, cutting is carried out at low speeds, with tools made of high-speed steel or equipped with carbide plates. Technological recommendations for machining by cutting, drilling, turning, pressure, milling and welding developed by Research Institute of Chemmash.

Welding

The argon-arc welding is carried out with a KhN63MVU-VI wire as an additive. During the electric arc welding the electrodes OZL-21 are used. During manual argon arc welding multilayer, the seam is reinforced (in height) by beads of limited cross section. With a minimum linear energy, the speed of welding should be maximum, taking into account the pauses between the imposition of the next rolls. The strength of welded joints in argon arc welding is more than 90% of the base material. Welds are resistant to cracking and intergranular corrosion.

Delivery

All the presented products of ХН63МБ grade are certified. The technical documentation includes data on the chemical composition, the limiting percentage of impurities, and the mechanical properties of products. From us you can buy in bulk any semi-finished products for large-scale productions. We also offer optimum conditions for retail buyers. The high level of service and responsiveness of service is the face of our company.

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All chromium-nickel alloys sold by Evek GmbH comply with state quality standards. We supply rolled metal products of standard and non-standard sizes in the shortest terms. High quality, reasonable prices and a wide range of products determine the face of our company. Becoming our regular customer, you can count on a system of discount discounts. Cooperation with us will help you realize any engineering plans. We are waiting for your orders on our site.