The effect of copper on temper-aging embrittlement was investigated using four heats of A533B steel. After quenched and tempered, each specimen was aged at 300, 400, 500, and 600°C for various lengths of time up to 1000 hours. The Charpy impact test was carried out and several specimens were subjected to scanning electron microscopic and Auger electron spectroscopic studies.
The results obtained are summarized as follows:
1) A533B steel bearing 0.37% copper showed the temper-aging embrittlement which was similar, in behavior, to the temper embrittlement caused by phosphorous under the same heat treatment condition.
2) The degree of the embrittlement was affected by aging temperature, aging time, and prior austenite grain size.
3) After aging, the copper enrichment was found at the fracture surface by Auger electron spectroscopic study.