Steel 20Х12НМВБФАР (CHS139)

Designation

Name	The value
Designation GOST Cyrillic	20Х12НМВБФАР
Designation GOST Latin	20X12HMBBFAP
Transliteration	20H12NMVBFAR
By chemical elements	20Cr12НMoWNbVNB

Name	The value
Designation GOST Cyrillic	ЧС139
Designation GOST Latin	ChC139
Transliteration	ChS139
By chemical elements	ZrС139

Description

20Х12НМВБФАР steel is used: for the production of bars with a diameter of 13 mm, tubular billets and pipes used for the fabrication of parts and structures of the active zones of nuclear energy (fast) and fusion reactors.

Note

Corrosion-resistant ferritic-martensitic steel.

Standards

Name	Code	Standards
Blanks. Of the workpiece. Slabs	В31	TU 14-131-1073-2010
Bars and shapes	В32	TU 14-131-1077-2010

Chemical composition

Standard	C	S	P	Mn	Cr	Si	Ni	Fe	Cu	N	Al	V	B	Ti	Mo	Nb	W	Ce	Zr	Co	Ta
TU 14-131-1077-2010	0.19-0.21	≤0.01	≤0.015	0.5-0.8	11-12.5	≤0.3	0.5-0.8	Rest	≤0.01	0.08-0.11	≤0.1	0.2-0.4	≤0.006	≤0.1	0.4-0.6	0.2-0.4	1-1.5	≤0.1	≤0.2	≤0.01	0.07-0.15

Fe is the basis.
According to TU 14-131-1073-2010 and TU 14-131-1077-2010 the chemical composition is given for steel grade 20Х12НМВБФАР-Ш (ЧС139-Ш). Cerium is introduced into the metal by calculation and chemical analysis is not determined. Boron and zirconium are introduced into the metal by calculation and their actual content is recorded in the quality document. The mass fraction of nitrogen and oxygen is optional, the deviation is not a rejection sign. The mass fraction (%) of non-ferrous metal impurities should be no more than: arsenic (As) 0.005, lead (Pb) 0.0005, cadmium (Cd) 0.0005, tin (Sn) 0.001, antimony (Sb) 0.001, bismuth (Bi) 0.0005, zinc (Zn) 0.001. The results of control of non-ferrous metal impurities are optional. The actual content is indicated in the quality document.

Mechanical properties

Section, mm	s_T\|s_0,2, MPa	σ_U, MPa	d₅, %
Tubular billet on the other 14-131-1073-2010 and bars on the other 14-131-1077-2010. Hardening in air, 1080-1100 °C (delay of 40-60 minutes) Leave at 680-720 °C (extract 1-3 hours), air cooling
20-25	≥490	≥640	≥12
20-25	≥343	≥490	≥12
20-25	≥265	≥295	≥22

Description mechanical marks

Name	Description
s_T\|s_0,2	Yield strength or limit of proportionality with a tolerance for residual deformation of 0.2%
σ_U	Limit short-term strength
d₅	Elongation after rupture

Technological properties

Name	The value
Macrostructure and pollution	The macrostructure of the workpiece in the delivery state should not have cracks, bubbles, bloat of the crust, delamination, traces of shrinkage, inclusions, visible to the naked eye. Allowable defects of the macrostructure shall not exceed: Central porosity, point heterogeneity and phase separation square - 1.0 points for each parameter; the common spotted liquation, edge spotty liquation and liquation Pousada - 2.0 points for each parameter. Layer-by-layer crystallization and the square of the increased travelmasti are not rejection symptom. Standards in scores of macrostructure optional and are entered in the document about quality. The content of nonmetallic inclusions by the maximum score shall not exceed: oxides of stroke (OS), silicates plastic (SP), silicates, non-deformed (SN) and sulfides (S) - 1.0 points for each parameter; the point oxides (FROM), silicates fragile (CX) and the nitrides and carbonitrides point (NT) - 2.0 points for each parameter; the nitrides and carbonitrides stroke (NA) - 3.0 points.
Particularities of production of goods	Tubular billet of diameter from 63 to 85 mm comes with ukonom not less than 10, the tubular billet with a diameter of 85 mm comes with ukonom at least 4. The ingots subjected to homogenizing annealing at temperatures below 1160° C for 6 hours, allowed to reconcile the homogenizing annealing, heating under hot deformation. The tubular billet is supplied in the heat treated condition according to the mode: heating to a temperature of (800±20) °C, cooling with the furnace to a temperature of 600 °C, then air cooling.
Features of heat treatment	The ingots subjected to homogenizing annealing at temperatures below 1160 °C for 6 hours, allowed to reconcile the homogenizing annealing, heating under hot deformation. The rods are supplied in heat treated condition according to the mode: heating to a temperature of (800±20) °C, cooling with the furnace to a temperature of 600°C, then air cooling.