EFFECTS OF REDUCTION, SQUARE ROOT OF THICKNESS AND SPREAD CONSTANT ON SPREAD FOR HOT FLAT ROLLED STEEL (HC SS316)

Abstract

The increasing tendency towards automation of the rolling process together with the trend towards more stringent specifications for hot rolled products, particularly wide strip for subsequent cold rolling, makes it highly desirable to assess the effects reduction, square root of thickness and spread constant have on spread for steels (HC SS316) hot flat rolled at low strain rates.

The spread coefficient (SPECO 1, SPECO 2 and SPECO 3) increased gradually as reduction increased from 8% to 25% with average values of 0.065, 0.057 and 0.039 respectively for both low and high speeds of 9.32mm/s and 133mm/s.

For square root of thickness (SRTHS) varying between 1.04 1.16, spread coefficient, SPECO 1 was 0.057 0.076; SPECO 2 was 0.0480.069 and SPECO 3 was 0.025-0.056 for low and high speeds of 9.32mm/s and 133mm/s.

The effect of spread constant, Z1 on spread coefficient (SPECO 1, SPECO 2 and SPECO 3) is contrary to that of reduction and that of square root of thickness (SRTHS). As spread constant, Z1 increased, spread coefficient decreased for both low and high speeds of 9.32mm/s and 133mm/s.