Accession Number:

AD0770216

Title:

Exploratory Development on the Hydrogen Embrittlement of High Strength Steel During Machining

Descriptive Note:

Final rept. 1 Apr-30 Jun 1973

Corporate Author:

BOEING AEROSPACE CO SEATTLE WA

Personal Author(s):

• Das, Bhagwan K.

Report Date:

1973-09-01

Pagination or Media Count:

95.0

Abstract:

The experimental program was undertaken to investigate the possibility of machining fluids being a source of hydrogen for a given high strength aerospace structural alloy. Unexpected catastrophic failure of high strength steel structures can occur as a result of hydrogen embrittlement if the material absorbs high levels of hydrogen during fabrication or when the hardware is in use. Test specimens made of AISI 4340 high strength steel of known hydrogen concentration were subjected to a specified schedule of gentle and abusive milling and grinding operations using different machining fluids. Following the machining operations the specimens were analyzed for excess hydrogen above the base level with a Boeing developed Ultrasensitive Hydrogen Analysis System. A total of six different machining fluids with different active chemical components were used in this study. Experimental results are presented with a statistical analysis of the hydrogen concentration data.

Descriptors:

• *HIGH STRENGTH ALLOYS
• *STEEL
• *HYDROGEN EMBRITTLEMENT
• MACHINING
• GAS ANALYSIS
• DISLOCATIONS
• DIFFUSION
• SULFUR
• ABSORPTION
• OILS
• LUBRICANTS
• GRINDING
• CHLORINE COMPOUNDS

Subject Categories:

• Properties of Metals and Alloys

Distribution Statement:

APPROVED FOR PUBLIC RELEASE