Question

what methods can be used to prevent hydrogen damage (in each of them )

- hydrogen embrittlement

- voids and blisters

- hydride formation

Answer 1

methods that can be used to prevent hydrogen damage in hydrogen embrittlement

multi pronged approach is required for prevention of hydrogen embrittlement

.1.preventing hydrogen absorption wherever possible

hydrogen may be introduce during During melting entrapped during solidification

2.eliminating residual stresses from part before processing .

3. baking after processing so hydrogen can be removed before it can damage part .

the initial cause is same for hydrogen embrittlement that is penetration of atomic hydrogen into metal .

coating technique can avoid or reduce hydrogen embrittlement .

by avoiding cathodic cleaning by use of alkaline soak clening & anodic cleaning

-Methods that can be use to prevent hydrogen damage in case of voids & blisters

Hydrogen blisters are subsurface planar cavities .

Prevention of hydrogen blisters can be done by avoiding impurity in steel

as main cause is hydrogen ,one should avoid hydrogen

we can reduce hydrogen & to be on safer side we have to use baking process to remove hydrogen if its present .

there are several methods as discussed prior to avoid hydron in process are,coating ,anodic cleaning.

Blisters usually occurs in low grade steel with low strength.

-Methods that can be use to prevent hydride formation :

hydride forming metal are titanium, vanadium, zirconium etc become brittle & fracture due to introduction of subsequent diffusion of hydrgen into metal.

in all of of the process the prevention key is reducing or avoiding hydrogen cantact with metal .

hydride forming metal undergoes hydrogen embrittlement & become fracture.