As　the　core　equipment　of　the　hydrogenation　unit,　the　safe　operation　of　the　hydrogenation　heat　exchanger　is　of　great　significance　to　the　devel-opment　of　petrochemical　industry　in　China.　Due　to　the　long-term　operation　under　severe　working　conditions　such　as　high　temperature,　high　pressure　and　hydrogen　exposure,　the　hydrogenation　heat　exchanger　is　frequently　subject　to　leakage　and　cracking　accidents　caused　by　hydrogen　embrittlement,　resulting　in　unplanned　shutdown.　Therefore,　the　nickel-based　alloys　Incoloy　825　and　AISI　321　stainless　steel　for　hydrogenation　heat　exchangers　were　selected　as　the　research　objects.　The　electrochemical　dynamic　hydrogen　charging　slow　strain　rate　tensile　test　(SSRT)　was　used.　At　the　same　time,　the　XRD　and　SEM　was　used　to　analyze　the　change　of　the　samples＇　physical　properties　and　fractures　before　and　after　hy-drogen　charging.　The　comparative　study　on　deterioration　tendency,　fracture　behavior　and　hydrogen　resistance　under　hydrogen　environment　of　two　kinds　of　materials　is　carried　out.　As　test　results　shown,　()　321　will　convert　to　martensite　while　825　produce　hydrides　under　the　action　of　hydro-gen;()　hydrogen　can　significantly　reduce　the　plasticity　of　321　and　825　materials,　and　the　plastic　loss　caused　by　hydrogen　will　increase　with　the　increase　of　hydrogen　charging　current　density;　()both　321　and　825　show　dimple　type　fractures　when　stretched　in　air.　With　the　increase　of　hydro-gen　charging　current　density,　321　transforms　into　a　mixed　fracture　mode　of　intergranular　cracking　and　quasi-cleavage　type　transgranular　crac-king,　and　825　transforms　to　quasi-cleavage　fracture.　In　conclusion,　under　the　stress/　hydrogen　interaction,　the　austenite　with　good　hydrogen　resistance　of　321　stainless　steel　is　converted　to　martensite,　so　the　hydrogen　resistance　of　321　stainless　steel　is　worse　than　that　of　825　nickel-based　alloy.　©　2022　Cailiao　Daobaoshe/　Materials　Review.　All　rights　reserved.