Standard Test Method for Process Control Verification to Prevent Hydrogen Embrittlement in Plated or Coated Fasteners

Importancia y uso:

5.1 This test method establishes a means to verify the prevention, to the extent possible, of IHE in steel fasteners during manufacture by maintaining strict controls during production operations such as surface preparation, pretreatments, and plating or coating. It is intended to be used as a qualification test for new or revised plating or coating processes and as a periodic inspection audit for the control of a plating or coating process.

5.2 Passing this test allows fasteners to be stressed in tension to the minimum specified tensile load in air with almost no possibility of time delayed fracture in air as a result of IHE from processing. If the amount of residual hydrogen is not sufficient to induce cracking or fracture in the specimen under worst case conditions, then it can be concluded that all of the lots of fasteners processed during that period will not have sufficient residual hydrogen from processing to induce hydrogen embrittlement of the fasteners under stress in air if the process remains in control, unchanged and stable.

5.3 If certified specimens with demonstrated sensitivity to IHE, processed with the fasteners, have a threshold ≥75 % of the incremental step load notched bend fracture stress, NFS(B)_F1624, it is assumed that all fasteners processed the same way during the period will also pass any sustained load IHE test.

Subcomité:

F16.93

Referida por:

F2833-11R17, F3019_F3019M-19, F3125_F3125M-23, F1136_F1136M-11R19, F3393-24, F2882_F2882M-17, B0633-23, A0193_A0193M-24, F1941_F1941M-16, A0194_A0194M-24, A0574-21, A0194_A0194M-24

Volúmen:

01.09

Número ICS:

21.060.01 (Fasteners in general)

Palabras clave:

coating; delayed failure; displacement control; EHE; fasteners; hydrogen embrittlement; IHE; incremental step load; loading rate; plating; steel; threshold;