Accession Number : ADA954158

Title :   Defective Helmet Steel.

Descriptive Note : Partial rept.,

Corporate Author : WATERTOWN ARSENAL LABS MA

Personal Author(s) : Hurlich,A.

Report Date : 28 AUG 1943

Pagination or Media Count : 15

Abstract : Defects in helmet stock which have been found to impair its deep drawing qualities consist of: (1) Undissolved carbides; (2) Decarburization; (3) Martensite streaks resulting from uncropped ingot piping. Of these defects, both decarburization and martensite streaks can be detected by microscopic examination, magnetic tests, and cupping tests. Undissolved carbides can be detected by microscopic examination, but not by any magnetic test. It is as yet uncertain that the deleterious effects of undissolved carbides can be shown by a cup test. Microscopic examination thus appears to be the best and most certain means of revealing defects in helmet stock, and its use as a inspection tool is worthy of consideration. From the investigation of helmet steels performed at this Arsenal it may be concluded that the deep drawing of the M1 helmet in one major operation is so severe a cold deformation that, unless the steel is absolutely free of all defests, considerable draw breakage will occur.

Descriptors :   *STEEL, COLD DRAWING, DEFECTS(MATERIALS), MICROSCOPY

Subject Categories : Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE