022Cr12Ni9Cu2NbTi、Custom 455 是一種超低碳的沉淀硬化馬氏體不銹鋼,具有高的強度和耐大氣腐蝕性。
022Cr12Ni9Cu2NbTi、Custom 455 不(bu)銹(xiu)鋼在溫(wen)(wen)度(du)(du)(du)區間900~1260℃極易鍛造(zao),適宜的鍛造(zao)加熱和(he)均熱溫(wen)(wen)度(du)(du)(du)為1040~1150℃,終鍛溫(wen)(wen)度(du)(du)(du)應控制(zhi)在815~925℃,可(ke)獲得較(jiao)細的晶粒(li)尺(chi)(chi)寸,鍛后(hou)(hou)(hou)空冷。鍛后(hou)(hou)(hou)應進(jin)行固(gu)溶處(chu)理,固(gu)溶溫(wen)(wen)度(du)(du)(du)為816~843℃,隨后(hou)(hou)(hou)快冷,若截面較(jiao)小可(ke)以水淬,組織為全馬氏體組織,硬度(du)(du)(du)為30~35HRC。生產(chan)企(qi)業(ye)一般均以固(gu)溶狀態(tai)的產(chan)品供貨,用戶(hu)加工后(hou)(hou)(hou)只需進(jin)行時(shi)(shi)效處(chu)理以獲得最后(hou)(hou)(hou)的性(xing)能。時(shi)(shi)效溫(wen)(wen)度(du)(du)(du)可(ke)在480~560℃選擇,保溫(wen)(wen)4h,空冷,時(shi)(shi)效后(hou)(hou)(hou)的尺(chi)(chi)寸變化僅為-0.001mm/mm。固(gu)溶和(he)時(shi)(shi)效處(chu)理后(hou)(hou)(hou)鋼的力學性(xing)能見表9.19和(he)表9.20。
022Cr12Ni9Cu2NbTi、Custom 455 不(bu)銹鋼在固(gu)(gu)溶處理(li)后可以立(li)即進(jin)(jin)行(xing)冷作(zuo)加工(gong)(gong)(gong)(gong)。對于深沖(chong)或脹形(xing)工(gong)(gong)(gong)(gong)藝(yi),由于變(bian)形(xing)是局部的,加工(gong)(gong)(gong)(gong)后須進(jin)(jin)行(xing)二(er)次固(gu)(gu)溶處理(li)(退火)。其他冷加工(gong)(gong)(gong)(gong),如(ru)冷拉、冷軋,因為在固(gu)(gu)溶狀(zhuang)態(tai)的加工(gong)(gong)(gong)(gong)硬化率低,可進(jin)(jin)行(xing)較(jiao)大變(bian)形(xing)量的冷加工(gong)(gong)(gong)(gong),獲得較(jiao)高的強度,而不(bu)需二(er)次固(gu)(gu)溶處理(li)。最后進(jin)(jin)行(xing)時效處理(li)。
022Cr12Ni9Cu2NbTi、Custom 455 不銹鋼可焊(han)性優良,可采用同成(cheng)分(fen)的(de)焊(han)接材料進(jin)行焊(han)接,一(yi)般(ban)不需焊(han)前預熱(re)和(he)焊(han)后(hou)熱(re)處理。
022Cr12Ni9Cu2NbTi、Custom 455 不銹鋼在通常的大氣環境和淡水中有良好的抗蝕能力,在35℃食鹽水噴濺和室溫下5%FeCl3水溶液中的耐點蝕性能良好。Costom 455鋼在包括海洋大氣等多種腐蝕環境下的應力腐蝕性能是良好的,并隨時效溫度的提高而進一步得到改善。