GOST 19442-74

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  ГОСТ 19442-74

GOST 19442−74 Bars for blades and bars for coupling blades of steam turbines made of corrosion-resistant and heat-resistant steel. Specifications (with Amendments No. 1, 2)

GOST 19442−74
Group В32

INTERSTATE STANDARD

BARS FOR BLADES AND BARS FOR COUPLING BLADES OF STEAM
TURBINES MADE OF CORROSION-RESISTANT AND HEAT-RESISTANT STEEL

Specifications

Contour bars for blades and bars for coupling blades of steam turbines made
of corrosion-resistant and high temperature steel.
Specifications

ISS 77.140.60
OKP 09 5800

Date of introduction 1975−01−01

Promulgated by decree of the State Committee of standards of the USSR Council of Ministers dated January 23, 1974 N 223

Limitation of actions taken by Protocol No. 4−93 of the Interstate Council for standardization, Metrology and certification (ICS 4−94)

EDITION with Amendments No. 1, 2, approved in October 1979, October 1984 (IUS 12−79, 1−85).


This standard applies to hot rolled, cold rolled and cold drawn shaped bars for steam turbine blades and cold rolled and cold drawn round and half-round bars for coupling blades of steam turbines made of corrosion-resistant and heat-resistant steel, designed for operation at temperatures up to 580 °C.

Indicators of technical level established by this standard, comply with the requirements of the highest quality.

(Changed edition, Rev. N 2).

1. TECHNICAL REQUIREMENTS

1.1. Shaped bars for semicircular blades and bars for coupling blades must be manufactured in accordance with the requirements of the present standard, using technical documentation and drawings, approved in the prescribed manner.

1.2. Twisting semicircular bars for coupling blades along the axis of the rod should not exceed 15° per 1 m length.

The curvature of the semicircular bars for coupling blades should be no more than 6 mm per 1 m length.

(Changed edition, Rev. N 1).

1.3. Round bars for coupling blades of manufactures 3, 3A and 4 precision grades and dimensions according to GOST 14955−77.

1.4. Length of shaped bars for the blades and connection blades should be at least 1.0 m.

At the request of the consumer made of shaped bars for the blades with a length multiple of the length of the blanks blades.

1.5. Shaped bars for the blades are made with clipped ends without distorting the profile.

Clipped to the ends of the bars are not allowed cracks and delaminations.

1.6. Shaped bars for blades made of rods and strips, supplied by GOST 18968−73 of steel 08KH13 (0Х13), 08KH13-sh, 12H13 (1Х13), 12H13-sh, 20X13 (2X13), 20X13-sh, 15KH11MF (1Х11МФ), 15KH11MF-sh, 15KH12VNMF (1Х12ВНМФ, ЭИ802), 15KH12VNMF-sh, 20KH12VNMF (2Х12ВНМФ, ЭП428), 20KH12VNMF-sh, 18KH11MNFB (2Х11МФБН, ЭП291), 18KH11MNFB-III according to GOST 5632−72.

Note. At the customer’s request shaped bars for the blades of steel of these brands are made from a metal vacuum-arc remelting and metal vacuum-induction melting.

1.7. Bars for coupling blades are made of round rods or a semi-circular strip of steel grades 12H13 (1Х13), 12H13-sh, 20X13 (2X13), 20X13-sh, 15KH11MF (1Х11МФ), 15KH11MF-sh, 20KH12VNMF (2Х12ВНМФ, ЭП428), 20KH12VNMF-III according to GOST 5632−72.

Note. Bars and rods of steel grades and 12H13 12H13-sh manufactured with a mass fraction of carbon not more than 0.12% of Nickel and not more than 0.4%.

1.8. The surface of the shaped bars for blades and bars for coupling blades should be smooth and clean. Hot rolled bars shaped to the shoulder blades should be cleaned from scale.

On the surface of hot rolled bars shaped to blades are not allowed, rolled, cracked, birdhouses, flaw, cheshuichatoe, rolling films, undercuts, sunsets, wrinkles, risks, remains current.

Allowed small Rabina, traces of Stripping defects, prints from rolls and small scratches mechanical origin, provided that their depth does not exceed half the limit of unilateral deviations on the size of the rod.

1.9. On the surface of cold rolled and cold drawn shaped bars for blades and bars for coupling blades of defects are not allowed. For cold rolled and cold drawn bars quality surface finishes should meet the group In GOST 14955−77.

Roughness cold-drawn and cold-rolled shaped bars for blades and bars for coupling blades of the parameter should be not more than 1.25 µm according to GOST 2789−73.

1.10. The degree of infestation rolled out the bubbles must not exceed the limits specified GOST 18968−73.

At the request of the consumer on the surface of cold rolled and cold drawn bars for coupling blades and edges of profile shapes rods for the blades of metal of electroslag remelting, vacuum arc remelting and vacuum induction melting, rolled, bubbles are not allowed.

1.11. The macrostructure of the shaped rods for the blades needs to match trebovaniye 5949−75. Fractures of bars should not have traces of shrinkage, bubbles, cracks, and slag inclusions.

1.6−1.11. (Changed edition, Rev. N 2).

1.12. Bars subjected to heat treatment (quenching+tempering). The recommended heat treatment is given in the Appendix.

1.13. Norms of mechanical properties when testing cylindrical specimens shall be as specified in table.1.

Table 1

Mechanical properties of bars when testing cylindrical specimens

Steel grade	Strength	Yield strength, MPa (kgs/mm)	Tensile strength, MPa (kgs/mm)	Regarding Sitel — ing elongation, %	Regarding Sitel — ing contraction, %	Impact strength, kJ/m(kgf·m/cm)	Hardness
			not less than				Indentation diameter, mm	The number of hardness HB
08KH13, 08KH13-SH	КП42	He at least 411 (42)	588 (60)	20	60	980 (10)	4,1−4,4	187−217
12H13, 12H13-SH	КП45	441−607 (45−62)	617 (63)	20	60	784 (8)	4,0−4,4	187−229
20X13, 20X13-SH	КП50	490−656 (50−67)	666 (68)	18	50	686 (7)	3,9−4,2	207−241
	КП70	686−882 (70−90)	833 (85)	15	50	-	3,5−3,8	255−302
15KH11MF, 15KH11MF-SH	КП55	539−656 (55−67)	686 (70)	15	50	588 (6)	3,8−4,1	217−255
	КП60	588−754 (60−77)	735 (75)	15	50	588 (6)	3,7−4,0	Are 229−269
	КП70	666−784 (68−80)	813 (83)	13	40	392 (4)	3,6−3,8	255−286
15KH12VNMF, 15KH12VNMF-SH	КП60	588−735 (60−75)	735 (75)	15	50	588 (6)	3,7−4,0	Are 229−269
20KH12VNMF, 20KH12VNMF-SH	КП60	588−754 (60−77)	735 (75)	15	50	588 (6)	3,7−4,0	Are 229−269
	КП70	666−784 (68−80)	813 (83)	13	35	392 (4)	3,6−3,9	241−286
18KH11MNFB, 18KH11MNFB-SH	КП60	588−735 (60−75)	735 (75)	15	50	588 (6)	3,8−4,0	229−255

Notes:

1. Standards for steel grade 20X13 with 686−882 yield strength MPa (79−90 kgf/mm) apply only to bars for coupling blades.

2. Rules apply the bars with the greatest thickness of 60 mm. When the thickness of the bars more than 60 mm are allowed the decrease of the relative elongation of 1% and a relative narrowing by 5% in comparison with specified in the table, as well as fracture toughness by 49 kJ/m(0.5 kgf·m/cm) at the rate of at least 784 kJ/m(8 kgf·m/cm) and 98 kJ/m(1 kgf·m/cm) at the rate of 784 kJ/m(8 kgf·m/cm) and bole

E.

3. Standards for toughness applies only to contoured rods for the blades with the greatest profile thickness 12 mm and more.

4. Standards for hardness apply to all of shaped bars for blades and bars for coupling blades with the largest width (diameter) of more than 10 mm.


Norms of mechanical properties during tensile testing of shaped bars for blades and bars for coupling blades shall be as specified in table.2.

Table 2

Mechanical properties when tested shaped bars for blades and bars for coupling blades

Steel grade	The quality	Tensile strength, MPa (kgs/mm)	Elongation %, not less	Hardness
				Indentation diameter, mm	The number of hardness HB
08KH13, 08KH13-SH	КП42	No less than 588 (60)	20	4,1−4,4	187−217
12H13, 12H13-SH	КП45	617−784 (63−80)	20	4,0−4,4	187−229
20X13, 20X13-SH	КП50	617−784 (63−80)	18	3,9−4,2	207−241
20X13, 20X13-SH	КП70	833−980 (85−100)	15	3,5−3,8	255−302
15KH11MF, 15KH11MF-SH	КП55	686−882 (70−90)	15	3,8−4,1	217−255
	КП60	735−931 (75−95)	15	3,7−4,0	Are 229−269
	КП70	813−980 (83−100)	13	3,6−3,8	255−286
15KH12VNMF, 15KH12VNMF-SH	КП60	735−931 (75−95)	15	3,7−4,0	Are 229−269
20KH12VNMF, 20KH12VNMF-SH	КП60	735−931 (75−95)	15	3,7−4,0	Are 229−269
	КП70	813−980 (83−100)	13	3,6−3,9	241−286
18KH11MNFB, 18KH11MNFB-SH	КП60	735−931 (75−95)	15	3,8−4,0	229−255

Notes:

1. For steel grades 20X13, 20X13-sh with strengths 833−980 MPa (85−100 kgf/mm) rule apply only to bars for coupling blades.

2. For bars with thickness more than 60 mm permitted a reduction of relative elongation of 1%.

3. When testing samples with an estimated length of 100 mm and bars with allowed reduction of the elongation at the rate of 16% and more than 4%, at a rate of 13%-15% to 2%.

1.14. Shaped bars for the blades with the greatest profile thickness less than 12 mm is subjected to flexure tests. The bending point should be no signs of cracks, tears and bundles.

1.13, 1.14. (Changed edition, Rev. N 2).

1.15. Decarburization cold-drawn and cold-rolled bars shaped to blades and connection blades are not allowed. Depth bezoperatsionnogo layer in hot-rolled bars and rods for the blades must not exceed 0,4 mm.

1.16. To obtain the desired mechanical properties may be performed no more than two heat treatments. Additional leave is not considered as reheat treatment.

1.17. The bars define the hardness at both ends, the difference in the hardness values should not exceed 20 HB.

2. ACCEPTANCE RULES

2.1. Rules of acceptance GOST 7566−94.

Shaped bars for blades and bars for coupling blades of attended parties. Party shaped bars for the blades should be profiled bars in the same bottoms, same size and same treatment and be accompanied by one document on quality according to GOST 7566−94.

The definition of the party round and half-round bars for coupling blades — according to GOST 14955−77.

Note. For electroslag melting are ingots smelted from a single source of melting.

2.2. Checking the size, appearance, and verification of hardness are subjected to all the bars of the party.

2.1, 2.2. (Changed edition, Rev. N 2).

2.3. To check the quality of bars from the party taken:

a) for chemical analysis — one rod;

b) for inspection of fracture — 2% of bars, but at least two bars;

C) to check the macrostructure etching — two rods;

g) to determine the mechanical properties — 2% of bars, but at least two bars with minimum and maximum hardness values;

d) to determine the depth bezoperatsionnogo layer — two wire (one sample);

e) to check the roughness of cold drawn and cold rolled bars — five bars (one sample).

2.4. On-demand user control of mechanical properties is carried out at twice the number of samples.

2.5. Verification of the impact, rolled, bubbles is carried out on all contoured bars for blades and bars for coupling blades.

(Changed edition, Rev. N 2).

3. TEST METHODS

3.1. Sampling for the determination of chemical composition is carried out according to GOST 7565−81.

Chemical composition of steel is determined according to GOST 28473−90, 12344−88 GOST, GOST 12345−2001, 12346−78 GOST, GOST 12347−77, 12348−78 GOST, GOST 12349−83, 12350−78 GOST, GOST 12351−81, 12352−81 GOST, GOST 12353−78, 12354−81 GOST, GOST 12355−78, 12356−81 GOST, GOST 12357−84, 12358−2002 GOST, GOST 12359−99, 12360−82 GOST, GOST 12361−2002, 12362−79 GOST, GOST 12363−79, 12364−84 GOST, GOST 12365−84.

(Changed edition, Rev. N 2).

3.2. Hardness test carried out according to GOST 9012−59.

3.3. Inspection of the exterior surface of bars is carried out without the use of magnifying devices. If necessary, the surface of bars for coupling blades of a width (diameter) of 3 mm or less, inspect at 10x magnification.

To identify defects allowed etching of the surface.

3.4. To obtain the fracture produce unilateral or bilateral incision with subsequent breaking away. The depth of the notches must not exceed 20% of the thickness of the rod. Checking the type of fracture is carried out visually without the use of magnifying tools.

3.5. Validation of the macrostructure of the shaped rods for the blades is performed on the etched transverse templeto according to GOST 10243−75.

3.4, 3.5. (Changed edition, Rev. N 2).

3.6. Sampling for mechanical tests carried out according to GOST 7564−97.

3.7. When testing the mechanical properties of the machined samples from each of the selected rod with the opposite end cut in longitudinal direction by one sample for tensile and two samples for impact strength. For bars with a profile thickness less than 12 mm instead of samples on the impact strength is cut in the longitudinal direction by one sample to bending of each end of the rod.

When testing mechanical properties of bars with real samples instead of the tensile specimens from each of the selected rod with the opposite ends of selected one sample in tension with the preservation of the geometric dimensions of the profile, with the exception of the sharp corners that round off a radius equal to half the thickness of the edges of the rod.

3.8. Tensile tests carried out according to GOST 1497−84 on samples of short cylindrical or contoured bars for blades and bars for coupling blades.

If it is not possible to produce a cylindrical sample with a diameter of 5 mm or more, tensile tests conducted on the molded bars for the blades or bars for coupling blades , where actual cross-section profile.

For sections with sectional area 50 mmand less tensile tests carried out on cylindrical samples with an estimated length of 100 mm or contoured rods for the blades or bars for coupling blades .

(Changed edition, Rev. N 2).

3.9. Test for impact strength is carried out according to GOST 9454−78 the samples of a type I concentrate form .

(Changed edition, Rev. N 1).

3.10. Shaped bars for the blades with the greatest profile thickness less than 12 mm is subjected to the Flexural testing, the machined sample or a shaped rod bent 180° around mandrel of diameter 2, where  — maximum thickness of the cross section.

Bend test carried out according to GOST 14019−80 on the sample width of 20 mm. At the request of the consumer to spend the cold bending shaped rod in the form of a profile without machining, and round off the sharp corners with a radius equal to half the edge thickness. The whole bend profile produces edges out.

(Changed edition, Rev. N 2).

3.11. Determination of the depth bezoperatsionnogo layer is carried out by the method agreed between the manufacturer and the consumer.

3.12. Surface roughness test the profilometer, profiling, optical devices or the working samples according to GOST 2789−73.

(Changed edition, Rev. N 1).

3.13. Test parts for the presence of rolled bubbles should be carried out by the method of magnetic flaw detection. Allowed verification of other methods, accuracy is not inferior to this method.

(Changed edition, Rev. N 2).

4. PACKING, MARKING, TRANSPORTATION AND STORAGE

4.1. Packing, marking, transportation and storage contoured rods for the blades — according to GOST 7566−94, bars for coupling blades — according to GOST 14955−77.

4.2. Bars made of steel produced by vacuum arc remelting or vacuum induction smelting, additionally marked with the letters «WA» or «VI».

Sec. 4. (Changed edition, Rev. N 2).

APPLICATION (recommended). THE HEAT TREATMENT

APP
Recommended

	The mode of heat treatment steel grades
A heat treatment process	08KH13	12H13, 20X13	15KH11MF	15KH12VNMF, 20KH12VNMF	18KH11MNFB
Hardening	1000 °C — 1050 °C, water or oil	1000 °C — 1050 °C, air or oil	1050 °C — 1100 °C, air or oil	1010 °C To 1060 °C, oil	1080 °C — 1130 °C, air or oil
Vacation	660 °C — 770 °C, air	660 °C — 770 °C, the air	660 °C — 770 °C, air	660 °C — 770 °C, air	660 °C — 770 °C, air

Note. For the shaped bars of steel produced electroslag and vacuum arc remelting, the temperature of heating for hardening is set to 10 °C — 20 °C lower than for metal smelting open.


APP. (Changed edition, Rev. N 1).