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)的(de)要求，一般滲(shen)碳層(ceng)的(de)厚度為o．8—1．5mm，當(dang)壓制(zhi)(zhi)含(han)硬質填料的(de)塑料時(shi)，模具滲(shen)碳層(ceng)厚度要求為1．3~15mm，壓制(zhi)(zhi)軟性(xing)(xing)塑料時(shi)滲(shen)碳層(ceng)厚度為0.8~1．2mm。滲(shen)碳層(ceng)的(de)碳含(han)量為0.7％~1.0％為佳。若采用(yong)碳氮共滲(shen)，則耐磨性(xing)(xing)、耐腐(fu)蝕(shi)性(xing)(xing)、抗氧化、防(fang)粘性(xing)(xing)就更好。

滲(shen)碳(tan)溫(wen)度(du)(du)(du)一般在900—920攝(she)氏度(du)(du)(du)之(zhi)間(jian)，復雜(za)型(xing)腔的(de)小型(xing)模具（模具鋼）可(ke)取840—860攝(she)氏度(du)(du)(du)中溫(wen)碳(tan)氮(dan)共滲(shen)。滲(shen)碳(tan)保溫(wen)時間(jian)為(wei)1~l0h．具體應根據對(dui)滲(shen)層厚度(du)(du)(du)的(de)要求來(lai)選擇。滲(shen)碳(tan)工藝以采用分級滲(shen)碳(tan)工藝為(wei)宜，即高溫(wen)階段(900—920攝(she)氏度(du)(du)(du))以快速將(jiang)碳(tan)滲(shen)入零件表(biao)層為(wei)主(zhu)．中溫(wen)階段(820~840攝(she)氏度(du)(du)(du))以增加(jia)滲(shen)碳(tan)層厚度(du)(du)(du)為(wei)主(zhu)，這樣(yang)在滲(shen)碳(tan)層內(nei)建立均勻合(he)理的(de)碳(tan)濃度(du)(du)(du)梯度(du)(du)(du)分布，便于直接淬火。

提高(gao)韌性(xing)的球(qiu)墨(mo)(mo)鑄(zhu)(zhu)(zhu)(zhu)鐵(tie)(tie)(tie)(tie)退火球(qiu)墨(mo)(mo)鑄(zhu)(zhu)(zhu)(zhu)鐵(tie)(tie)(tie)(tie)在鑄(zhu)(zhu)(zhu)(zhu)造過程(cheng)中(zhong)此普通灰口鑄(zhu)(zhu)(zhu)(zhu)鐵(tie)(tie)(tie)(tie)的白(bai)口傾(qing)向大(da)(da)，內應力(li)也較大(da)(da)，鑄(zhu)(zhu)(zhu)(zhu)鐵(tie)(tie)(tie)(tie)件(jian)(jian)很難得到(dao)(dao)純(chun)粹(cui)的鐵(tie)(tie)(tie)(tie)素(su)體(ti)(ti)(ti)(ti)(ti)(ti)或(huo)珠光(guang)(guang)(guang)體(ti)(ti)(ti)(ti)(ti)(ti)基體(ti)(ti)(ti)(ti)(ti)(ti)，為(wei)提高(gao)鑄(zhu)(zhu)(zhu)(zhu)鐵(tie)(tie)(tie)(tie)件(jian)(jian)的延性(xing)或(huo)韌性(xing)，常將鑄(zhu)(zhu)(zhu)(zhu)鐵(tie)(tie)(tie)(tie)件(jian)(jian)重(zhong)(zhong)新加熱到(dao)(dao)900-950℃并(bing)保(bao)(bao)溫(wen)(wen)足夠時間進(jin)行高(gao)溫(wen)(wen)退火，再爐(lu)冷(leng)到(dao)(dao)600℃出爐(lu)變(bian)(bian)(bian)冷(leng)。若鑄(zhu)(zhu)(zhu)(zhu)態(tai)組織由(you)(鐵(tie)(tie)(tie)(tie)素(su)體(ti)(ti)(ti)(ti)(ti)(ti)＋珠光(guang)(guang)(guang)體(ti)(ti)(ti)(ti)(ti)(ti))基體(ti)(ti)(ti)(ti)(ti)(ti)，以及(ji)(ji)球(qiu)狀石(shi)墨(mo)(mo)組成，為(wei)提高(gao)韌性(xing)，只需將珠光(guang)(guang)(guang)體(ti)(ti)(ti)(ti)(ti)(ti)中(zhong)滲碳體(ti)(ti)(ti)(ti)(ti)(ti)分解(jie)轉換為(wei)鐵(tie)(tie)(tie)(tie)素(su)體(ti)(ti)(ti)(ti)(ti)(ti)及(ji)(ji)球(qiu)狀石(shi)墨(mo)(mo)，為(wei)此將鑄(zhu)(zhu)(zhu)(zhu)鐵(tie)(tie)(tie)(tie)件(jian)(jian)重(zhong)(zhong)新加熱到(dao)(dao)700-760℃的共析溫(wen)(wen)度上下經保(bao)(bao)溫(wen)(wen)后爐(lu)冷(leng)至(zhi)600℃出爐(lu)變(bian)(bian)(bian)冷(leng)。工藝過程(cheng)是將基體(ti)(ti)(ti)(ti)(ti)(ti)為(wei)鐵(tie)(tie)(tie)(tie)素(su)體(ti)(ti)(ti)(ti)(ti)(ti)及(ji)(ji)珠光(guang)(guang)(guang)體(ti)(ti)(ti)(ti)(ti)(ti)的球(qiu)墨(mo)(mo)鑄(zhu)(zhu)(zhu)(zhu)鐵(tie)(tie)(tie)(tie)件(jian)(jian)重(zhong)(zhong)新加熱到(dao)(dao)850-900℃溫(wen)(wen)度，原鐵(tie)(tie)(tie)(tie)素(su)體(ti)(ti)(ti)(ti)(ti)(ti)及(ji)(ji)珠光(guang)(guang)(guang)體(ti)(ti)(ti)(ti)(ti)(ti)轉換為(wei)奧(ao)(ao)氏體(ti)(ti)(ti)(ti)(ti)(ti)，并(bing)有部分球(qiu)狀石(shi)墨(mo)(mo)溶解(jie)于奧(ao)(ao)氏體(ti)(ti)(ti)(ti)(ti)(ti)，經保(bao)(bao)溫(wen)(wen)后空冷(leng)奧(ao)(ao)氏體(ti)(ti)(ti)(ti)(ti)(ti)轉變(bian)(bian)(bian)為(wei)細珠光(guang)(guang)(guang)體(ti)(ti)(ti)(ti)(ti)(ti)，因此鑄(zhu)(zhu)(zhu)(zhu)件(jian)(jian)的強度提高(gao)。