Steel 04Х25Н5М2 (ДИ62)
|Designation GOST Cyrillic||04Х25Н5М2|
|Designation GOST Latin||04X25H5M2|
|By chemical elements||04Cr25Н5Mo2|
|Designation GOST Cyrillic||ДИ62|
|Designation GOST Latin||DI62|
|By chemical elements||CuИ62|
04Х25Н5М2 steel is used: for the manufacture of equipment for chemical industry, organic synthesis and production of sulfuric acid; equipment for pulp and paper industry; parts and welded structures operating in environments of increased aggressiveness: acetate, sulfate, phosphate environments.
Austenite corrosion resistant steel-ferritic class.
|Thermal and thermochemical treatment of metals||В04||STP 26.260.484-2004|
|Blanks. Of the workpiece. Slabs||В31||TU 14-1-4582-89, TU 14-1-2639-79|
According to TU 14-1-2639-79, the chemical composition is presented for steel grade 04X25N5M2 (DI62). Deviations from the established norms of chemical composition are allowed: for silicon +0.10%, for nickel ± 0.20%. The content of residual elements in accordance with GOST 5632. At the request of the consumer, the steel is alloyed with niobium. The content of niobium should be within 10 · С ÷ 0,60%. Steel in this case has the designation 04X25N5M2B.
|Section, mm||sT|s0,2, MPa||σU, MPa||d5, %||y, %||KCU, kJ/m2|
|Bullion on the other 14-1-2639-79. The samples along the grain. Annealing in air 1000-1040 °C, air cooling|
|Bars hot rolled and forged at STP 26.260.484-2004. Quenching in water or air 1000-1040 °C + Vacation at 350-400 °C, air cooling|
Description mechanical marks
|sT|s0,2||Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2%|
|σU||Limit short-term strength|
|d5||Elongation after rupture|
|y||The relative narrowing|
|Macrostructure and pollution||In the macrostructure of steel on the other 14-1-2639-79 should be no traces of shrinkage, bubbles, cracking, and gross foreign metal and slag inclusions visible to the naked eye. On the surface of ingots shall not be longitudinal cracks, slag inclusions with a depth of more than 5 mm and mesh height of more than 3 mm. the Defects must be removed by cutting or Stripping. The ratio of the width to the depth of cutting must be not less than 6. The depth of the cutting or Stripping shall not exceed 10% of the sides of the ingot.|
|Features of heat treatment||Steel products to eliminate the tendency to intergranular corrosion are subjected to hardening regime: heating up to 1020±20 °C, cooling in water, excluding products with a cross section up to 10mm, which cooled in air. The holding time at the heating for hardening to products with a wall thickness up to 10 mm - 30 min, over 10 mm — 20 min + 1 min per 1 mm maximum thickness. Vacation at 350-400 °C, exposure 2 h. two-hour exposure can be applied to the partial withdrawal and redistribution of residual stresses after avtomatizovani. Steel 04Х25Н5М2 at 700-900 °C is prone to embrittlement in connection with the formation of Sigma phase, therefore, heating and cooling in this temperature range must be performed with maximum speed. Products austenite-ferritic steels do not require heat treatment after welding.|
|Corrosion resistance||04Х25Н5М2 steel has higher corrosion resistance than steel 08KH21N6M2T, including against pitting corrosion, and its strength is much higher. Steel resistant to stress corrosion cracking (CU).|