Method for manufacturing a strip having a variable thickness and associated strip

A variable thickness strip having, along its length, first areas having a first thickness (e+s) and second areas having a second thickness (e) smaller than the first thickness (e+s), the variable thickness strip being made of an alloy comprising by weight:

• 34.5%≤Ni≤53.5%
• 0.15%≤Mn≤1.5%
• 0≤Si≤0.35%
• 0≤C≤0.07%
• optionally:
• 0≤Co≤20%
• 0≤Ti≤0.5%
• 0.01%≤Cr≤0.5%
• the remainder being iron and impurities necessarily resulting from manufacturing,
• the first areas having a first average grain size (G1ASTM) and the second areas having a second average grain size (G2ASTM), the absolute value difference between the first grain size (G1ASTM) and the second grain size (G2ASTM) being less than or equal to 0.5 numbers according to the ASTM E112-10 standard.

A blank having, along its length, at least one first reinforced area having a first thickness (e+s) and at least one second area having a second thickness (e) smaller than the first thickness (e+s), the blank being made of an alloy comprising by weight:

• 34.5%≤Ni≤53.5%
• 0.15%≤Mn≤1.5%
• 0≤Si≤0.35%0≤C≤0.07%
• optionally:
• 0≤Co≤20%
• 0≤Ti≤0.5%
• 0.01%≤Cr≤0.5%
• the remainder being iron and impurities necessarily resulting from manufacturing,
• the at least one first reinforced area having a first average grain size (G1ASTM) and the at least one second area having a second average grain size (G2ASTM), the absolute value difference between the first grain size (G1ASTM) and the second grain size (G2ASTM) being less than or equal to 0.5 numbers according to the ASTM E112-10 standard.

A cryogenic tube segment made of an alloy comprising by weight:

• 34.5%≤Ni≤53.5%
• 0.15%≤Mn≤1.5%
• 0≤Si≤0.35%
• 0≤C≤0.07%
• optionally:
• 0≤Co≤20%
• 0≤Ti≤0.5%
• 0.01%≤Cr≤0.5%
• the remainder being iron and impurities necessarily resulting from manufacturing, and which segment comprises a cylindrical central area having a thickness (e) and cylindrical reinforced ends, the cylindrical reinforced ends being formed in one piece with the central area, the cylindrical reinforced ends having a thickness (e+s) greater than the thickness (e) of the central area,
• the cylindrical reinforced ends having a first average grain size (G1ASTM) and the cylindrical central area having a second average grain size (G2ASTM), the absolute value difference between the first grain size (G1ASTM) and the second grain size (G2ASTM) being less than or equal to 0.5 numbers according to the ASTM E112-10 standard.