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Effects of annealing treatment on microstructure and hardness in the 28 wt% Cr cast iron with Mo/W addition |
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| รหัสดีโอไอ | |
| Creator | Kittikhun RUANGCHAI |
| Title | Effects of annealing treatment on microstructure and hardness in the 28 wt% Cr cast iron with Mo/W addition |
| Contributor | Ruangdaj TONGSRI, John Thomas Harry PEARCE, Torranin CHAIRUANGSRI, Amporn WIENGMOON |
| Publisher | Metallurgy and Materials Science Research Institute Chulalongkorn University |
| Publication Year | 2564 |
| Journal Title | Journal of Metals, Materials and Minerals |
| Journal Vol. | 31 |
| Journal No. | 2 |
| Page no. | 89-95 |
| Keyword | High chromium cast iron, Microstructure, Annealing, Hardness, Carbide |
| ISSN | 8576149 |
| Abstract | In this study, the effects of annealing on the hardness and microstructure of 28 wt%สCr-2.6 wt%สC iron with 1.4 wt%สMo/1 wt%สW additionสhave been investigated.สThe as-cast samples wereสheatedสto 800_ and held for 4 hสfollowed by slow cooled with a cooling rate of 20__h-1สto 500_.Microstructures were characterized byสX-ray diffractometry,สoptical microscopy, scanning electron microscopy andสenergy-dispersive X-ray spectroscopy.สVickers macro-hardness and micro-hardnessสwere measured.สIt was found that the as-cast microstructure in the hypoeutectic 28 wt%สCr ironสwithout Mo or W additionสconsisted of primary austenite dendrite, eutectic M7C3สcarbideสand martensite.สIn the iron with 1.4 wt%สMo addition, multiple eutectic carbides of M7C3,สM23C6สandสM6C were observed. In contrast the addition of 1 wt% Wสchanged the structure toสhypereutecticสcontaining primary M7C3,สeutectic M7C3สand martensite.สAfter the annealing heat treatment, ferriteส+secondary carbides and someสpearlite were present in the irons, due to decomposition of austenite during annealing.สThe macro-hardness in the as-cast condition of the iron without alloying and the irons with 1.4 wt%สMo/ส1 wt%สWสaddition wereส506, 529, and 576 HV30, respectively.สAnnealing heat treatment reduced the macro-hardness to aboutส390, 463, and 428 HV30, respectively. |
