Group B 73
Head of organization Head of organization
p / n B-8715 p / p A-1795
December 9, 1976… 1976
R.P. Romashin I. O. L.S. Khokhlov
Inv. No. 3195 Equivalent No. 27
CORROSION RESISTANT HIGH STRENGTH
Technical conditions unrestricted.
(instead of MRTU 3−632−67) 07/01/85①
Term of introduction from
Agreed: Developed by:
Deputy head Deputy head
enterprises PO Box R-6762 Enterprises PO Box M-5481
10/12/1976 February 24, 1976 1976
Deputy Head of Department
enterprises p / i A-1950 standardization
05/06/1976 02.20.76 1976
Council of the USSR Ministry
Registered and entered in the register
03.24.77 for No. 1667381
December 27, 1976
④ Change 4 23.05.90
① Change 1
These specifications apply to high-strength corrosion-resistant spring wire designed for the manufacture of coil springs operating in corrosive environments.
1. TECHNICAL REQUIREMENTS
1.1. Corrosion-resistant spring high-strength wire must meet the requirements of these specifications.
1.2. Basic parameters and dimensions.
1.2.1. Spring wire, depending on the mechanical properties, must be made of three strength groups:
normal — H;
high-strength — B;
high-strength critical purpose — VO.
1.2.2. For each strength group, the wire diameter must correspond to that indicated in table. 1.
|Wire group||Wire diameter, mm|
0.11 — 8.01
0.11 — 8.01
0.51 — 10.01
1.2.3. The diameter of the wire and the maximum deviations for it must correspond to those indicated in table. 2.
Table 2 Continued table. 2
|+ 0, 08|
Designation of a spring wire, brand 12X18H10T ④, group B, with a diameter of 0.51 mm when ordering and in the documentation of another product:
Wire 12X18H10T ④ -V-0.51 TU 3−1002−77
1.2.4. At the request of the consumer, the wire is manufactured in intermediate sizes with maximum deviations for the nearest larger size.
1.2.5. The ovality of the wire should not exceed the maximum deviations in diameter.
1.3.1. The wire should be made of steel grade 12X18H10T with a chemical composition in accordance with GOST 5632−72 (the documents to which the links are given are indicated in the «List of referenced documents» placed at the end of the technical specifications) with narrowed limits on the content of the following elements:
carbon 0.09 — 0.12%
for manganese 1.50 — 2.00%
chrome 17.00 — 18.00%
for nickel 10.0 — 11.0%
for titanium 5 (C-0.02) -0.7%, where C is the carbon content.
1.3.2. Hot rolled steel for wire fabrication is subject to macrostructure, alpha-phase and non-metallic inclusions control. Control of the content of the alpha phase and non-metallic inclusions is carried out on hot-rolled installations with a side of a square of 40 mm or 100−125 mm. ③
The macrostructure of the steel should be free of traces of shrinkage looseness, subcrustal defects, foreign inclusions, fistulas and cracks visible to the naked eye.
The content of the alpha phase in steel workpiece with a side of a square of 40 mm ③ should not exceed 1 point, and in a workpiece of 100−125 mm — points 1.5.
The content of non-metallic inclusions should not exceed the titanium nitride content in a workpiece with a side of a square of 40 mm; there should not be more than 3 points, for each of the other types, 2 points for a 100−125 mm workpiece — 4 points. ③
The content of non-metallic inclusions for each of the other types should not exceed score 2.
By agreement between the manufacturer and the consumer, the wire of other groups can be made from the same blank.
1.3.4. The wire is supplied in cold-worked condition.
1.3.5. The mechanical properties of wire of groups B and VO must meet the requirements specified in table. 3.
Ultimate tensile strength Н / (kgf / )
1.3.6. The mechanical properties of the wire of group H must meet the requirements specified in table. 4.
1.3.7. A wire with a diameter of less than 0.81 mm is tested for rupture with a knot, while the breaking force must be at least 50% of the breaking force of the same wire when tested without a knot.
Ultimate tensile strength, Н / (kgs / )
|Number of twists|
Note. Reduction of temporary resistance to wire breaking is allowed
with a diameter of 10.01 mm to 1180 N / (120 kgf / ).
1.3.8. The surface of the wire must be smooth, without cracks, sunsets, captivity, delamination and
Separate dents, nicks, risks, scratches and ripples are allowed on the surface, the depth of which should not be more than half of the maximum deviations in diameter, counting from the actual size.
1.3.9. The amount of chlorine ions on the surface of the VO group wire should not exceed 0.1 mg per 25 surface area.
1.3.10. At the request of the consumer, the wire must withstand the intergranular corrosion test.
1.3.11. At the request of the consumer, wire of groups B and BO with diameters from 0.11 to 5.51 mm after tempering at a temperature of (460 ± 10) ° C and holding for 30−60 minutes must withstand at least one twisting.
1.3.12. Wire of groups B and BO diameters indicated in table. 5 should not break or delaminate when wound around the rod.
|Wire diameter, mm||Rod diameter when wound||Number of turns, not less|
Equal to one diameter of the tested wire
Equal to two diameters of the tested wire
Equal to three diameters of the tested wire
Note. While satisfactory results are guaranteed, the winding test for
the manufacturer can be omitted.
1.13.13. Wire with a diameter of up to 0.3 mm should be made on spools, with a diameter of 0.3 to 0.6 mm — on spools or in coils, with a diameter over 0.6 mm — in coils.
1.3.14. Wire winding into coils or spools should be done in correct rows, without entangling the turns, and ensure its free winding. The ends of the wire in the coil should be neatly laid and easily found. When freeing the skein from knitting, the wire should not be folded into a «figure eight».
1.3.15. The inner diameter of the coil, depending on the diameter of the wire, must correspond to that indicated in table. 6.
|The diameter of the wire||Coil diameter, not less|
1.4.1. Wire marking — in accordance with GOST 18143−72 .
1.5.1. Wire packing — in accordance with GOST 18143−72 .
2. RULES OF ACCEPTANCE
2.1. Wire is accepted in lots. The batch should consist of wire of the same diameter, one heat to one group.
2.2. Each motor or wire spool is inspected and measured.
2.3. To check the chemical composition, one sample is taken from the initial melt — ladle according to GOST 7585−81 .
2.4. To check the mechanical properties of the wire, samples are taken from both ends of each coil and one sample from one end of each coil.
2.5. To check the wire for winding, samples are taken from both ends of the coil or from one end of the coil — 5% of the batch, but not less than five coils (spools).
2.6. For testing for intergranular corrosion, three samples are taken from each heat.
2.7. To check the content of the alpha phase and non-metallic inclusions, two samples are taken from the heat, cut from different hot-rolled billets and quenched at a temperature of 1150 ° C.
2.8. The number of samples taken for monitoring chlorine ions is set by the manufacturer.
2.9. Upon receipt of unsatisfactory test results, at least for one of the indicators, repeated tests are carried out on it on a double number of samples taken from coils or coils. Upon receipt of unsatisfactory results of repeated tests for at least one of the indicators, the batch is rejected or each coil, or each coil is taken separately.
3. CONTROL METHODS
3.1. The control of the diameter and ovality of the wire is carried out with a measuring tool that ensures the required measurement accuracy in two mutually perpendicular directions of one wire section, at least in three places of each coil.
3.2. The chemical composition of steel for the manufacture of wire is determined according to GOST 12344−7888 ④, GOST 12345−80 88 ④, GOST 12346−78, GOST 12347−77, GOST 12348−78, GOST 12349−83, GOST 12350−78, GOST 12352−81, GOST 12354−81, GOST 12356−81, GOST 20560−81 .
3.3. The macrostructure of hot-rolled steel is checked according to GOST 10243−75 .
3.4. Determination of the alpha-phase content is carried out by metallographic or magnetic method according to the manufacturer’s method in accordance with GOST 11878−66 .
3.5. Determination of the content of non-metallic inclusions is carried out according to the manufacturer’s method in accordance with GOST 1778−70 .
3.6. The tensile test of the wire is carried out in accordance with GOST 10446−80 .
3.7. In the knotted tensile test of the wire, the sample is tied in a simple knot without being tightly tightened. The ends of the sample are clamped with the grips of a tensile testing machine. The complete tightening of the knot occurs when the sample is stretched.
3.8. The surface of the wire is checked visually, the depth of the defect is determined by stripping. The place of the defect is cleaned with sandpaper or a file, followed by a comparative example of wire in the cleaned and not cleaned places.
To detect surface defects, the VO group wire is subjected to electropolishing or other cleaning and subsequent inspection.
Wire drawn by wet drawing, electropolishing or cleaning may not be possible.
The characteristics of wire defects are determined according to the standards given in Appendix 1.
3.9. Chlorine ions are determined according to the manufacturer’s method, while the manufacturer guarantees the standards provided for in clause 1.3.9 of these technical specifications.
3.10. Testing of wire for intergranular corrosion is carried out according to the AM GOST 6032−7684 method after tempering the sample at a temperature of (460 ± 10) ° C for 30−60 minutes.
3.11. The wire torsion test is carried out in accordance with GOST 1546−80 .
3.12. Wire winding test is carried out in accordance with GOST 10447−80 .
3.13. The list of equipment required for measuring and testing wire is given in Appendix 2.
4. TRANSPORTATION AND STORAGE
4.1. Transportation of wire made of steel grade 12X18H10T should be carried out by rail, road and air transport in covered vehicles (wagons or universal containers), small, wagon or container shipments.
Loading and unloading operations must be carried out in accordance with transport markings in accordance with GOST 14192−77 and hazard signs in accordance with GOST 19433−8188 ④.
4.2. Fastening of coils (coils) in bundles in railway vehicles and the rules for transporting products on them must be carried out in accordance with the requirements of the «Rules for the carriage of goods» and «Technical conditions for loading and securing goods» approved by the USSR Ministry of Railways ⑤.
Fastening of coils in bundles in road transport and the rules for transporting products on them must be carried out in accordance with the «General rules for the carriage of goods by road» approved by the Ministry of Road Transport of the RSFSR dated July 30, 1971 ⑤.
Fastening of coils in bundles in civil aviation and the rules for the carriage of products on them should be carried out in accordance with the «Manual for Freight Transportation on Domestic Air Lines of the USSR ⑤" approved by the Ministry of Civil Aviation on March 25, 1975 ⑤.
4.3. Wire storage under the conditions of 2 GOST 15150−69 .
5. MANUFACTURER’S WARRANTIES
5.1 The manufacturer guarantees the compliance of the spring wire with the requirements of these specifications, subject to the conditions of transportation and storage established by these specifications.