ALLOY TAPE 40KHNM
FOR ELASTIC ELEMENTS
The term of introduction is 05/01/18.
These specifications apply to a strip made of alloy 40KHNM, intended for the manufacture of elastic elements.
The tape is subdivided according to the manufacturing accuracy:
— normal accuracy in thickness and width;
— increased accuracy in thickness and width — «VS»;
— increased thickness accuracy — «B».
An example of a conventional designation: Tape 0.35 mm thick, 8 mm wide, increased accuracy in thickness and width from alloy 40KHNM:
Tape 40KHNM 0.35x8-VSh TU 1231−406−00187180−2018.
1.1. The dimensions of the tape and the maximum deviations for them must correspond to those indicated in table 1.
|Thickness||Limit deviations depending on manufacturing accuracy||Width||Limit deviations depending on manufacturing accuracy|
2.1. TECHNICAL REQUIREMENTS
2.1. The tape is made of alloy grade 40KHNM in accordance with GOST 10994.
2.2. The mechanical properties of the tape (spring angle and the number of bends), determined on heat treated samples, must correspond to those indicated in Table 2.
|Normal tape thickness, mm||Spring angle, in degrees, not less||Number of folds, not less|
Note: When checking the mechanical properties of the consumer, the heat treatment of the samples is carried out according to the mode specified in the supplier’s certificate.
2.3. The surface of the tape should be flat, clean and light.
2.4. There should be no sunsets, deep shells and scratches on the surface of the tape. Separate scratches, risks, shells, ripples, nicks, imprints from rolls, the depth or height of which does not exceed half of the maximum deviations in thickness, are allowed. Lamination in the tape is not allowed.
Roughness parameter Ra is no more than 0.63 microns in accordance with GOST 2789.
2.5. The tape is supplied with cut edges. There should be no burrs on the edges of the tape, the value of which exceeds half of the maximum deviations in thickness, as well as other defects with a depth of no more than half of the maximum deviations in width. Traces of abrasion are allowed.The roughness of the edge surface is not standardized.
3. Test methods.
3.1. Determination of the spring angle is carried out according to the GOST 15146 method and according to table. 3.
|Nominal tape thickness, mm||Mandrel diameter, mm|
3.2. Determination of the number of bends is made according to GOST 13813 and according to table. 4.
|Nominal tape thickness, mm||The radius of the jaws of the device, mm||Lever arm length of the device, mm|
4. Acceptance rules, other test methods, labeling, packaging, transportation and storage in accordance with GOST 14117.