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碳(tan)(tan)層(ceng)的(de)(de)要求，一般滲碳(tan)(tan)層(ceng)的(de)(de)厚(hou)度(du)(du)為o．8—1．5mm，當壓制含硬質(zhi)填(tian)料的(de)(de)塑(su)料時(shi)，模具滲碳(tan)(tan)層(ceng)厚(hou)度(du)(du)要求為1．3~15mm，壓制軟性(xing)塑(su)料時(shi)滲碳(tan)(tan)層(ceng)厚(hou)度(du)(du)為0.8~1．2mm。滲碳(tan)(tan)層(ceng)的(de)(de)碳(tan)(tan)含量為0.7％~1.0％為佳。若采用(yong)碳(tan)(tan)氮共(gong)滲，則(ze)耐磨性(xing)、耐腐蝕(shi)性(xing)、抗氧化、防粘性(xing)就更好。

滲(shen)(shen)(shen)(shen)碳(tan)溫(wen)(wen)度(du)(du)(du)一(yi)般(ban)在900—920攝氏度(du)(du)(du)之間，復(fu)雜型腔的(de)小型模(mo)(mo)具（模(mo)(mo)具鋼）可取840—860攝氏度(du)(du)(du)中溫(wen)(wen)碳(tan)氮共(gong)滲(shen)(shen)(shen)(shen)。滲(shen)(shen)(shen)(shen)碳(tan)保溫(wen)(wen)時間為1~l0h．具體應根據對滲(shen)(shen)(shen)(shen)層(ceng)(ceng)厚(hou)度(du)(du)(du)的(de)要求來選擇。滲(shen)(shen)(shen)(shen)碳(tan)工藝以采用分級滲(shen)(shen)(shen)(shen)碳(tan)工藝為宜，即高(gao)溫(wen)(wen)階段(900—920攝氏度(du)(du)(du))以快速將(jiang)碳(tan)滲(shen)(shen)(shen)(shen)入零(ling)件(jian)表層(ceng)(ceng)為主．中溫(wen)(wen)階段(820~840攝氏度(du)(du)(du))以增加滲(shen)(shen)(shen)(shen)碳(tan)層(ceng)(ceng)厚(hou)度(du)(du)(du)為主，這樣(yang)在滲(shen)(shen)(shen)(shen)碳(tan)層(ceng)(ceng)內建立均(jun)勻合理的(de)碳(tan)濃度(du)(du)(du)梯度(du)(du)(du)分布，便于直接淬火。

提(ti)高(gao)韌(ren)性(xing)(xing)的(de)球(qiu)墨鑄(zhu)(zhu)(zhu)(zhu)(zhu)鐵(tie)退(tui)火球(qiu)墨鑄(zhu)(zhu)(zhu)(zhu)(zhu)鐵(tie)在鑄(zhu)(zhu)(zhu)(zhu)(zhu)造過程中(zhong)此普通灰口鑄(zhu)(zhu)(zhu)(zhu)(zhu)鐵(tie)的(de)白口傾向(xiang)大，內應力也較(jiao)大，鑄(zhu)(zhu)(zhu)(zhu)(zhu)鐵(tie)件(jian)(jian)很難得到純(chun)粹的(de)鐵(tie)素體(ti)(ti)(ti)(ti)(ti)或(huo)珠(zhu)光(guang)(guang)(guang)體(ti)(ti)(ti)(ti)(ti)基(ji)體(ti)(ti)(ti)(ti)(ti)，為(wei)(wei)提(ti)高(gao)鑄(zhu)(zhu)(zhu)(zhu)(zhu)鐵(tie)件(jian)(jian)的(de)延(yan)性(xing)(xing)或(huo)韌(ren)性(xing)(xing)，常將鑄(zhu)(zhu)(zhu)(zhu)(zhu)鐵(tie)件(jian)(jian)重(zhong)新(xin)加熱(re)到900-950℃并保溫足夠時間進(jin)行高(gao)溫退(tui)火，再爐冷(leng)到600℃出爐變(bian)冷(leng)。若鑄(zhu)(zhu)(zhu)(zhu)(zhu)態組(zu)織由(鐵(tie)素體(ti)(ti)(ti)(ti)(ti)＋珠(zhu)光(guang)(guang)(guang)體(ti)(ti)(ti)(ti)(ti))基(ji)體(ti)(ti)(ti)(ti)(ti)，以及(ji)球(qiu)狀(zhuang)石墨組(zu)成，為(wei)(wei)提(ti)高(gao)韌(ren)性(xing)(xing)，只需將珠(zhu)光(guang)(guang)(guang)體(ti)(ti)(ti)(ti)(ti)中(zhong)滲碳體(ti)(ti)(ti)(ti)(ti)分解(jie)(jie)轉換為(wei)(wei)鐵(tie)素體(ti)(ti)(ti)(ti)(ti)及(ji)球(qiu)狀(zhuang)石墨，為(wei)(wei)此將鑄(zhu)(zhu)(zhu)(zhu)(zhu)鐵(tie)件(jian)(jian)重(zhong)新(xin)加熱(re)到700-760℃的(de)共析溫度上下經保溫后爐冷(leng)至600℃出爐變(bian)冷(leng)。工(gong)藝過程是(shi)將基(ji)體(ti)(ti)(ti)(ti)(ti)為(wei)(wei)鐵(tie)素體(ti)(ti)(ti)(ti)(ti)及(ji)珠(zhu)光(guang)(guang)(guang)體(ti)(ti)(ti)(ti)(ti)的(de)球(qiu)墨鑄(zhu)(zhu)(zhu)(zhu)(zhu)鐵(tie)件(jian)(jian)重(zhong)新(xin)加熱(re)到850-900℃溫度，原鐵(tie)素體(ti)(ti)(ti)(ti)(ti)及(ji)珠(zhu)光(guang)(guang)(guang)體(ti)(ti)(ti)(ti)(ti)轉換為(wei)(wei)奧(ao)(ao)氏體(ti)(ti)(ti)(ti)(ti)，并有部(bu)分球(qiu)狀(zhuang)石墨溶解(jie)(jie)于奧(ao)(ao)氏體(ti)(ti)(ti)(ti)(ti)，經保溫后空冷(leng)奧(ao)(ao)氏體(ti)(ti)(ti)(ti)(ti)轉變(bian)為(wei)(wei)細珠(zhu)光(guang)(guang)(guang)體(ti)(ti)(ti)(ti)(ti)，因此鑄(zhu)(zhu)(zhu)(zhu)(zhu)件(jian)(jian)的(de)強(qiang)度提(ti)高(gao)。