Through-Thickness Residual Stresses, Microstructure, and Mechanical Properties of Electron Beam-Welded CA6NM Martensitic Stainless Steel after Postweld Heat Treatment

Table 1

As-received material heat treatment conditions prior to welding.

Material		ASTM A743 Grade CA6NM
Heat treatments prior to welding	Normalizing	1020°C ± 10°C for 6 h followed by air cooling to below Mf of 90°C [13]
	Double tempering	600°C ± 20°C for 8 h followed by air cooling to below Mf of 90°C
		580°C ± 15°C for 8 h followed by air cooling to room temperature

Double tempers are employed for CA6NM to meet the maximum requirement set by NACE of 23 HRC for castings intended for wet H₂S environments to mitigate the risk of stress corrosion cracking.