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(dui)滲碳(tan)層(ceng)(ceng)(ceng)的要(yao)求(qiu)，一般滲碳(tan)層(ceng)(ceng)(ceng)的厚度(du)為(wei)o．8—1．5mm，當壓制含硬質填(tian)料的塑料時，模具滲碳(tan)層(ceng)(ceng)(ceng)厚度(du)要(yao)求(qiu)為(wei)1．3~15mm，壓制軟性(xing)塑料時滲碳(tan)層(ceng)(ceng)(ceng)厚度(du)為(wei)0.8~1．2mm。滲碳(tan)層(ceng)(ceng)(ceng)的碳(tan)含量為(wei)0.7％~1.0％為(wei)佳(jia)。若采(cai)用碳(tan)氮共(gong)滲，則耐磨性(xing)、耐腐蝕性(xing)、抗氧化、防粘(zhan)性(xing)就(jiu)更(geng)好。

滲(shen)碳(tan)(tan)溫(wen)度一般在(zai)900—920攝(she)氏(shi)度之(zhi)間(jian)，復雜型腔(qiang)的小型模具(ju)（模具(ju)鋼）可取(qu)840—860攝(she)氏(shi)度中溫(wen)碳(tan)(tan)氮共滲(shen)。滲(shen)碳(tan)(tan)保溫(wen)時間(jian)為1~l0h．具(ju)體應(ying)根據對滲(shen)層(ceng)厚度的要求來選擇。滲(shen)碳(tan)(tan)工藝(yi)以采用(yong)分(fen)級滲(shen)碳(tan)(tan)工藝(yi)為宜，即高溫(wen)階(jie)段(900—920攝(she)氏(shi)度)以快速將碳(tan)(tan)滲(shen)入零件表層(ceng)為主(zhu)．中溫(wen)階(jie)段(820~840攝(she)氏(shi)度)以增加滲(shen)碳(tan)(tan)層(ceng)厚度為主(zhu)，這樣在(zai)滲(shen)碳(tan)(tan)層(ceng)內建(jian)立均勻(yun)合理(li)的碳(tan)(tan)濃(nong)度梯度分(fen)布，便于直(zhi)接淬火。

提(ti)(ti)高(gao)韌(ren)性(xing)的(de)球(qiu)(qiu)(qiu)(qiu)墨(mo)(mo)鑄(zhu)(zhu)鐵(tie)(tie)(tie)退火球(qiu)(qiu)(qiu)(qiu)墨(mo)(mo)鑄(zhu)(zhu)鐵(tie)(tie)(tie)在(zai)鑄(zhu)(zhu)造過(guo)程(cheng)中(zhong)此(ci)普通灰(hui)口(kou)鑄(zhu)(zhu)鐵(tie)(tie)(tie)的(de)白口(kou)傾向大(da)，內應力也較大(da)，鑄(zhu)(zhu)鐵(tie)(tie)(tie)件(jian)(jian)(jian)很難得到(dao)純粹(cui)的(de)鐵(tie)(tie)(tie)素體(ti)(ti)或(huo)珠(zhu)(zhu)光(guang)(guang)體(ti)(ti)基(ji)(ji)體(ti)(ti)，為(wei)(wei)提(ti)(ti)高(gao)鑄(zhu)(zhu)鐵(tie)(tie)(tie)件(jian)(jian)(jian)的(de)延性(xing)或(huo)韌(ren)性(xing)，常將鑄(zhu)(zhu)鐵(tie)(tie)(tie)件(jian)(jian)(jian)重(zhong)(zhong)新(xin)加(jia)(jia)(jia)熱到(dao)900-950℃并保(bao)(bao)溫(wen)(wen)足夠時間進(jin)行高(gao)溫(wen)(wen)退火，再(zai)爐(lu)冷(leng)(leng)到(dao)600℃出爐(lu)變(bian)冷(leng)(leng)。若鑄(zhu)(zhu)態(tai)組(zu)織由(鐵(tie)(tie)(tie)素體(ti)(ti)＋珠(zhu)(zhu)光(guang)(guang)體(ti)(ti))基(ji)(ji)體(ti)(ti)，以(yi)及(ji)球(qiu)(qiu)(qiu)(qiu)狀石墨(mo)(mo)組(zu)成，為(wei)(wei)提(ti)(ti)高(gao)韌(ren)性(xing)，只需(xu)將珠(zhu)(zhu)光(guang)(guang)體(ti)(ti)中(zhong)滲碳體(ti)(ti)分(fen)解(jie)轉(zhuan)(zhuan)換為(wei)(wei)鐵(tie)(tie)(tie)素體(ti)(ti)及(ji)球(qiu)(qiu)(qiu)(qiu)狀石墨(mo)(mo)，為(wei)(wei)此(ci)將鑄(zhu)(zhu)鐵(tie)(tie)(tie)件(jian)(jian)(jian)重(zhong)(zhong)新(xin)加(jia)(jia)(jia)熱到(dao)700-760℃的(de)共析溫(wen)(wen)度上下(xia)經保(bao)(bao)溫(wen)(wen)后爐(lu)冷(leng)(leng)至600℃出爐(lu)變(bian)冷(leng)(leng)。工(gong)藝過(guo)程(cheng)是將基(ji)(ji)體(ti)(ti)為(wei)(wei)鐵(tie)(tie)(tie)素體(ti)(ti)及(ji)珠(zhu)(zhu)光(guang)(guang)體(ti)(ti)的(de)球(qiu)(qiu)(qiu)(qiu)墨(mo)(mo)鑄(zhu)(zhu)鐵(tie)(tie)(tie)件(jian)(jian)(jian)重(zhong)(zhong)新(xin)加(jia)(jia)(jia)熱到(dao)850-900℃溫(wen)(wen)度，原(yuan)鐵(tie)(tie)(tie)素體(ti)(ti)及(ji)珠(zhu)(zhu)光(guang)(guang)體(ti)(ti)轉(zhuan)(zhuan)換為(wei)(wei)奧氏(shi)體(ti)(ti)，并有部(bu)分(fen)球(qiu)(qiu)(qiu)(qiu)狀石墨(mo)(mo)溶(rong)解(jie)于(yu)奧氏(shi)體(ti)(ti)，經保(bao)(bao)溫(wen)(wen)后空冷(leng)(leng)奧氏(shi)體(ti)(ti)轉(zhuan)(zhuan)變(bian)為(wei)(wei)細(xi)珠(zhu)(zhu)光(guang)(guang)體(ti)(ti)，因此(ci)鑄(zhu)(zhu)件(jian)(jian)(jian)的(de)強度提(ti)(ti)高(gao)。