ANISOTROPY AND ITS RELATIONSHIP TO DEEP DRAWING OF A 5% CR TOOL STEEL (H-11) FOR THE HAWK MISSILE,
Abstract
CONCLUSIONS: The primary causes for poor drawability of the H-11 sheet material were excessively high values of planar anisotropy (delta R), caused by low hot-rolling finishing temperatures, and incomplete spheroidization. Material exhibiting minimum elongation values of 25%, maximum yield strength values of 55,000 psi, and a maximum delta R value of /.25/ resulted in acceptable drawability for the conditions imposed. All heats of the H-11 sheet evaluated, with the exception of heat 82 (R' = 1.04, 1.09, 1.27, 1.52), exhibited R' values from .90 - .99. This range at best indicated only fair drawability. Consequently, even with drawing variables kept at optimum levels, the severity of 'hydro-forming' the accumulator dome, caused a base level failure rate during drawing, of approximately 2-9%. Only when R>1.0 could one expect the base level failure rate to be less than this range. Since R' increases linearly as delta R in order to have improved drawability (increasing R'), an increase in the tendency toward earing (increase in delta R) must be tolerated. Therefore, a point must be established where the severity of earing (delta R) is more detrimental than the improvement in drawability (R').
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1966
- Accession Number
- AD0634669
Entities
People
- James D. Colgate
- Robert M. Colton
Organizations
- United States Army Research Laboratory