A.氧化鋯; B.碳化硅; C.氮化硅; D.耐灰材料; E.玻璃;
A.低碳合金鋼; B.合金滲碳鋼; C.合金調(diào)質(zhì)鋼; D.合金結(jié)構(gòu)鋼; E.合金工具鋼;
A.20Cr B.35CrMo C.38CrMoAl D.40Cr E.45