Process for treating a body of stainless steel so as to promote its adherence to a rubber composition

A process for treating a body of steel to favor adherence to a composition comprising at least one rubber, containing the following features:

• a body at least the surface of which is stainless steel containing at least 0.02% and at most 0.2% carbon, at least 3% and at most 20% nickel, at least 12% and at most 28% chromium, the sum of the nickel and chromium being at least equal to 20% and at most equal to 35%, all of these percentages being by weight;
• the structure of the steel comprises at least 20 by volume of martensite and it is without austenite or contains less than 80% thereof by volume;
• the surface of the body is activated and it is then treated with at least one starting silane so that it is covered with a film constituted exclusively, or substantialy exclusively, of one or more silanes having the following formula:
• ##STR2## in which R represents an organic radical containing at least one function capable of reacting with at least one element of the composition;
• each OR' represents a group capable of reacting with an oxide or hydroxide of the surface of the stainless steel;
• each R" represent, independently, hydrogen, a cyclic or acyclic organic radical, or a halogen;
• a, which may be zero, is equal to at most 2.