Steel Р8Ф2К8М5 (ЭП658)

Designation

Name	The value
Designation GOST Cyrillic	Р8Ф2К8М5
Designation GOST Latin	P8F2K8M5
Transliteration	R8F2K8M5
By chemical elements	-

Name	The value
Designation GOST Cyrillic	ЭП658
Designation GOST Latin	EP658
Transliteration	EhP658
By chemical elements	-

Description

Р8Ф2К8М5 steel is used: for the production of rolled used in the manufacture of a special tool cutting properties which are retained to a temperature of 650 °C.

Standards

Name	Code	Standards
Bars and shapes	В32	TU 14-1-2966-80

Chemical composition

Standard	C	S	P	Mn	Cr	Si	Ni	V	Mo	W	Co
TU 14-1-2966-80	0.95-1.05	≤0.03	≤0.035	≤0.4	3.8-4.4	≤0.5	≤0.4	1.8-2.5	4.6-5.2	5.5-6	7.5-8.5

According to TU 14-1-2966-80 the chemical composition is given for steel grade P8F2K8M5 (EP658). In the steel, the proportion of manganese is exceeded by 0.10%.
In the steel P8F2K8M5 (EP658) the following technological additives are introduced according to the calculation in quantities:
- titanium - 0.02-0.10%,
- boron - 0.001-0.003%,
- lanthanum - 0.001-0.003%,
- nitrogen - 0.030-0.070%.
Permissible deviations from the norms of chemical composition in accordance with GOST 19265.

Technological properties

Name	The value
Macrostructure and pollution	In the macrostructure of bars of steel Р8Ф2К8М5 should not be podnasadochnogo of rychlosti, residues shrinkage, delamination, bubbles, cracks. When assessing the allowed macrostructure: Central porosity - no more than points 1 - for bars with diameter or thickness up to 50 mm; not more than a score of 2 for bars with diameter or thickness greater than 50 mm to 100 mm inclusive. Fracture of steel should be homogeneous, fine-grained. Carbide inhomogeneity in steel depending on the size of the cross section shall not exceed the standards (maximum permissible score of carbide heterogeneity): up to 20 mm - 2 points; over 20 up to 40 mm - 3 points; St. 40 to 60 mm. - 4 points; over 60 to 80 mm - 5 points; Carbide heterogeneity of steel is controlled by the method and scale №1 GOST 19265 on samples thermally treated under the regime: Heating for hardening to 1210-1240 °C to + Leave for hours at 680-700 °C. Depth bezoperatsionnogo layer is determined according to GOST 1763. In the control according to the method of Sadovsky samples subjected to heat treatment regime: Heating for hardening up to 1230-1250 °C + Quenching in the first bath at 180-190 °C (extract 10 min) + annealing in the second bath at 540-560 °C (10 min exposure). over 80 mm to 100 mm - 6 points.
Microstructure	Depth bezoperatsionnogo layer of steel must not exceed the side of 0.5 mm. plus 1% of the diameter of the circle, the sides of the square, the thickness of the strip.
Particularities of production of goods	Steel on the other 14-1-2966-80 supplied annealed with a hardness of not more than HB 269. The red hardness of steel should provide a hardness of not less than HRC58, after a four-hour tempering at the temperature of 630 °C.