Accession Number:

ADA021174

Title:

Development of a Weldable High Strength Steel.

Descriptive Note:

Final rept. Mar 73-Feb 75,

Corporate Author:

GENERAL DYNAMICS/FORT WORTH TEX FORT WORTH DIV

Personal Author(s):

Report Date:

1975-09-01

Pagination or Media Count:

136.0

Abstract:

An existing 10Ni-8Co-2Cr-1Mo steel HY180 was modified to a higher strength level to meet the need for weldable and fracture-resistant high-strength steel alloys required in current and future airframe structural applications. This steel, which relies on the precipitation of a secondary hardening precipitate in a highly dislocated lath martensite matrix at an elevated aging temperature, appeared to be an excellent candidate for modification to meet high toughness requirements at high strength levels 230-250 Ksi UTS. Eight experimental alloys were melted where the level of alloy addition was controlled by factorial and regression analysis techniques. Six of the eight experimental alloys met the mechanical property requirements. The selected alloy composition 14Co-10Ni-2Cr-1Mo-0.16C was scaled-up to a 2000 lb VIMVAR heat with no apparent decrease in mechanical properties. Preliminary results indicate low fatigue crack growth rates both in ambient and corrosive environments, improved SN fatigue and good general corrosion resistance. The 14Co-10Ni-2Cr-1Mo-0.16C steel AF1410 was found to be quite weldable by conventional arc weld processes.

Subject Categories:

  • Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE