熱處理對于有高硬度、高耐磨性和高韌性要求的塑料模具，表面熱處理廠家要選用滲碳鋼來制造，并把滲碳、淬火和低溫回火作為最終熱處理，表面熱處理廠家對滲(shen)碳層(ceng)(ceng)的(de)要(yao)求，一般滲(shen)碳層(ceng)(ceng)的(de)厚度(du)為(wei)(wei)o．8—1．5mm，當壓制(zhi)(zhi)含硬質填料(liao)(liao)的(de)塑(su)料(liao)(liao)時，模(mo)具滲(shen)碳層(ceng)(ceng)厚度(du)要(yao)求為(wei)(wei)1．3~15mm，壓制(zhi)(zhi)軟性塑(su)料(liao)(liao)時滲(shen)碳層(ceng)(ceng)厚度(du)為(wei)(wei)0.8~1．2mm。滲(shen)碳層(ceng)(ceng)的(de)碳含量為(wei)(wei)0.7％~1.0％為(wei)(wei)佳。若采(cai)用碳氮共滲(shen)，則耐磨性、耐腐蝕性、抗氧(yang)化、防粘(zhan)性就(jiu)更好。

滲(shen)(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)溫(wen)(wen)度(du)(du)(du)(du)一般(ban)在900—920攝(she)氏(shi)度(du)(du)(du)(du)之間，復(fu)雜型腔的(de)小(xiao)型模具(ju)(ju)（模具(ju)(ju)鋼）可取840—860攝(she)氏(shi)度(du)(du)(du)(du)中溫(wen)(wen)碳(tan)(tan)(tan)氮共(gong)滲(shen)(shen)(shen)(shen)(shen)。滲(shen)(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)保(bao)溫(wen)(wen)時間為(wei)(wei)1~l0h．具(ju)(ju)體應根據對(dui)滲(shen)(shen)(shen)(shen)(shen)層厚(hou)度(du)(du)(du)(du)的(de)要(yao)求來選擇。滲(shen)(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)工藝以采用分(fen)級滲(shen)(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)工藝為(wei)(wei)宜，即(ji)高溫(wen)(wen)階段(duan)(900—920攝(she)氏(shi)度(du)(du)(du)(du))以快速將碳(tan)(tan)(tan)滲(shen)(shen)(shen)(shen)(shen)入零(ling)件(jian)表層為(wei)(wei)主(zhu)．中溫(wen)(wen)階段(duan)(820~840攝(she)氏(shi)度(du)(du)(du)(du))以增加滲(shen)(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)層厚(hou)度(du)(du)(du)(du)為(wei)(wei)主(zhu)，這樣在滲(shen)(shen)(shen)(shen)(shen)碳(tan)(tan)(tan)層內建立均勻合理的(de)碳(tan)(tan)(tan)濃(nong)度(du)(du)(du)(du)梯度(du)(du)(du)(du)分(fen)布，便于直接淬火。

提(ti)(ti)高(gao)韌(ren)(ren)性的(de)(de)球(qiu)墨鑄(zhu)(zhu)鐵(tie)退(tui)火球(qiu)墨鑄(zhu)(zhu)鐵(tie)在鑄(zhu)(zhu)造過程中此(ci)(ci)普通灰(hui)口(kou)鑄(zhu)(zhu)鐵(tie)的(de)(de)白口(kou)傾向大，內(nei)應(ying)力也較(jiao)大，鑄(zhu)(zhu)鐵(tie)件(jian)很(hen)難得到(dao)(dao)純粹(cui)的(de)(de)鐵(tie)素(su)體(ti)(ti)(ti)(ti)(ti)或珠(zhu)(zhu)光(guang)體(ti)(ti)(ti)(ti)(ti)基(ji)(ji)體(ti)(ti)(ti)(ti)(ti)，為(wei)(wei)(wei)(wei)提(ti)(ti)高(gao)鑄(zhu)(zhu)鐵(tie)件(jian)的(de)(de)延性或韌(ren)(ren)性，常將鑄(zhu)(zhu)鐵(tie)件(jian)重新加(jia)(jia)熱到(dao)(dao)900-950℃并保(bao)(bao)溫(wen)足(zu)夠時間進(jin)行(xing)高(gao)溫(wen)退(tui)火，再(zai)爐(lu)冷(leng)(leng)到(dao)(dao)600℃出(chu)爐(lu)變冷(leng)(leng)。若鑄(zhu)(zhu)態組織由(鐵(tie)素(su)體(ti)(ti)(ti)(ti)(ti)＋珠(zhu)(zhu)光(guang)體(ti)(ti)(ti)(ti)(ti))基(ji)(ji)體(ti)(ti)(ti)(ti)(ti)，以及球(qiu)狀(zhuang)石墨組成，為(wei)(wei)(wei)(wei)提(ti)(ti)高(gao)韌(ren)(ren)性，只需將珠(zhu)(zhu)光(guang)體(ti)(ti)(ti)(ti)(ti)中滲碳體(ti)(ti)(ti)(ti)(ti)分解轉(zhuan)換為(wei)(wei)(wei)(wei)鐵(tie)素(su)體(ti)(ti)(ti)(ti)(ti)及球(qiu)狀(zhuang)石墨，為(wei)(wei)(wei)(wei)此(ci)(ci)將鑄(zhu)(zhu)鐵(tie)件(jian)重新加(jia)(jia)熱到(dao)(dao)700-760℃的(de)(de)共析(xi)溫(wen)度上下經保(bao)(bao)溫(wen)后爐(lu)冷(leng)(leng)至600℃出(chu)爐(lu)變冷(leng)(leng)。工(gong)藝過程是將基(ji)(ji)體(ti)(ti)(ti)(ti)(ti)為(wei)(wei)(wei)(wei)鐵(tie)素(su)體(ti)(ti)(ti)(ti)(ti)及珠(zhu)(zhu)光(guang)體(ti)(ti)(ti)(ti)(ti)的(de)(de)球(qiu)墨鑄(zhu)(zhu)鐵(tie)件(jian)重新加(jia)(jia)熱到(dao)(dao)850-900℃溫(wen)度，原鐵(tie)素(su)體(ti)(ti)(ti)(ti)(ti)及珠(zhu)(zhu)光(guang)體(ti)(ti)(ti)(ti)(ti)轉(zhuan)換為(wei)(wei)(wei)(wei)奧氏體(ti)(ti)(ti)(ti)(ti)，并有部分球(qiu)狀(zhuang)石墨溶解于奧氏體(ti)(ti)(ti)(ti)(ti)，經保(bao)(bao)溫(wen)后空冷(leng)(leng)奧氏體(ti)(ti)(ti)(ti)(ti)轉(zhuan)變為(wei)(wei)(wei)(wei)細(xi)珠(zhu)(zhu)光(guang)體(ti)(ti)(ti)(ti)(ti)，因此(ci)(ci)鑄(zhu)(zhu)件(jian)的(de)(de)強度提(ti)(ti)高(gao)。