Table 3.

Summary of literature data devoted to study the effects of cryo-treatment on microstructure and mechanical properties.

First Author, [#]	Cryogenic Treatment	Rival Treatment	Material	Microstructure Alteration	Outcome
Bensely [98]	SCT and DCT	N.A.	EN 353	Higher volume fraction of retained austenite and fine carbides	SCT treated specimens show better fatigue life in contrast to DCT and CHT.
Baldissera [99,100,101]	DCT	CrN coating through PVD	AISI 302	Formation of microsecondary cracks on surface	Tensile strength and fatigue life significantly improved.
Baldissera [102,103,104]	DCT	N.A.	18NiCrMo5 carburized steel	N.A.	Hardness (+2.4 HRC) and UTS (+11%) were improved.
Bouzada [105]	DCT	N.A.	7075 aluminum alloy	Accretion of submicrometric particles near and at the grain boundaries	Yield strength, tensile strength and hardness were ameliorated
Lei [106]	DCT	N.A.	2219-T87	Uniform grain-boundary strengthening, substructure strengthening, and aging precipitation strengthening	Better weldability obtained.
Vahdat [107]	DCT	N.A.	Medium carbon-low alloy tool steel	Formation of secondary carbides	Tensile toughness increased.
Niaki [108]	DCT	N.A.	1.2542 tool steel	Elimination of retained austenite and uniform distribution of secondary carbides	Nonsignificant changes in fatigue life were recorded.
Senthilkumar [109]	DCT	N.A.	En 8 steel	Uniform martensite structure	Significant improvement of ultimate tensile strength was traced.
Araghchi [110]	DCT	N.A.	2024 aluminum	Formation of large needle-like S´ precipitates with different orientation	Reduction of residual stress by 250% and hardness increase have been reported.
Gu [111]	DCT	N.A.	TB8 metastable β titanium alloy	High volume fraction of needle-like α phase in martensite matrix	Microhardness and tensile strength were improved.
Nießen [112]	DCT	N.A.	EN 1.4418 steel	Stabilization of reverted austenite	Impact toughness is a time dependent variable on temperature, and it is directly affected by volume fraction of austenite.