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(tan)(tan)(tan)(tan)層(ceng)的要求，一(yi)般滲(shen)碳(tan)(tan)(tan)(tan)層(ceng)的厚度為(wei)o．8—1．5mm，當壓制(zhi)含硬質填(tian)料的塑(su)料時(shi)，模具滲(shen)碳(tan)(tan)(tan)(tan)層(ceng)厚度要求為(wei)1．3~15mm，壓制(zhi)軟(ruan)性(xing)(xing)(xing)塑(su)料時(shi)滲(shen)碳(tan)(tan)(tan)(tan)層(ceng)厚度為(wei)0.8~1．2mm。滲(shen)碳(tan)(tan)(tan)(tan)層(ceng)的碳(tan)(tan)(tan)(tan)含量為(wei)0.7％~1.0％為(wei)佳(jia)。若采用(yong)碳(tan)(tan)(tan)(tan)氮共滲(shen)，則耐磨(mo)性(xing)(xing)(xing)、耐腐(fu)蝕性(xing)(xing)(xing)、抗氧化、防(fang)粘(zhan)性(xing)(xing)(xing)就更好(hao)。

滲(shen)碳(tan)(tan)溫(wen)度(du)一般(ban)在(zai)900—920攝(she)氏(shi)度(du)之間(jian)(jian)，復(fu)雜型(xing)腔(qiang)的小型(xing)模具(ju)（模具(ju)鋼）可取840—860攝(she)氏(shi)度(du)中溫(wen)碳(tan)(tan)氮(dan)共滲(shen)。滲(shen)碳(tan)(tan)保溫(wen)時(shi)間(jian)(jian)為(wei)(wei)1~l0h．具(ju)體(ti)應(ying)根據對(dui)滲(shen)層厚度(du)的要求來選(xuan)擇。滲(shen)碳(tan)(tan)工藝(yi)以(yi)采用分級滲(shen)碳(tan)(tan)工藝(yi)為(wei)(wei)宜，即高溫(wen)階段(900—920攝(she)氏(shi)度(du))以(yi)快速(su)將碳(tan)(tan)滲(shen)入(ru)零(ling)件表層為(wei)(wei)主(zhu)．中溫(wen)階段(820~840攝(she)氏(shi)度(du))以(yi)增加滲(shen)碳(tan)(tan)層厚度(du)為(wei)(wei)主(zhu)，這樣在(zai)滲(shen)碳(tan)(tan)層內建(jian)立均(jun)勻合理(li)的碳(tan)(tan)濃度(du)梯度(du)分布，便于直接淬火。

提高韌性(xing)(xing)(xing)的(de)(de)(de)球墨(mo)(mo)鑄(zhu)鐵(tie)(tie)(tie)退火球墨(mo)(mo)鑄(zhu)鐵(tie)(tie)(tie)在鑄(zhu)造過(guo)程中(zhong)此普通灰口鑄(zhu)鐵(tie)(tie)(tie)的(de)(de)(de)白口傾向大(da)，內應(ying)力也較大(da)，鑄(zhu)鐵(tie)(tie)(tie)件(jian)很難得到純(chun)粹的(de)(de)(de)鐵(tie)(tie)(tie)素體(ti)(ti)(ti)(ti)(ti)或珠(zhu)光體(ti)(ti)(ti)(ti)(ti)基體(ti)(ti)(ti)(ti)(ti)，為(wei)提高鑄(zhu)鐵(tie)(tie)(tie)件(jian)的(de)(de)(de)延性(xing)(xing)(xing)或韌性(xing)(xing)(xing)，常將(jiang)鑄(zhu)鐵(tie)(tie)(tie)件(jian)重(zhong)新加熱(re)到900-950℃并保溫(wen)(wen)足夠時間進行高溫(wen)(wen)退火，再爐冷(leng)到600℃出(chu)爐變冷(leng)。若鑄(zhu)態(tai)組(zu)織(zhi)由(鐵(tie)(tie)(tie)素體(ti)(ti)(ti)(ti)(ti)＋珠(zhu)光體(ti)(ti)(ti)(ti)(ti))基體(ti)(ti)(ti)(ti)(ti)，以及(ji)球狀石墨(mo)(mo)組(zu)成，為(wei)提高韌性(xing)(xing)(xing)，只需將(jiang)珠(zhu)光體(ti)(ti)(ti)(ti)(ti)中(zhong)滲碳體(ti)(ti)(ti)(ti)(ti)分(fen)解轉(zhuan)換為(wei)鐵(tie)(tie)(tie)素體(ti)(ti)(ti)(ti)(ti)及(ji)球狀石墨(mo)(mo)，為(wei)此將(jiang)鑄(zhu)鐵(tie)(tie)(tie)件(jian)重(zhong)新加熱(re)到700-760℃的(de)(de)(de)共析溫(wen)(wen)度(du)(du)上下經(jing)保溫(wen)(wen)后爐冷(leng)至600℃出(chu)爐變冷(leng)。工藝(yi)過(guo)程是將(jiang)基體(ti)(ti)(ti)(ti)(ti)為(wei)鐵(tie)(tie)(tie)素體(ti)(ti)(ti)(ti)(ti)及(ji)珠(zhu)光體(ti)(ti)(ti)(ti)(ti)的(de)(de)(de)球墨(mo)(mo)鑄(zhu)鐵(tie)(tie)(tie)件(jian)重(zhong)新加熱(re)到850-900℃溫(wen)(wen)度(du)(du)，原鐵(tie)(tie)(tie)素體(ti)(ti)(ti)(ti)(ti)及(ji)珠(zhu)光體(ti)(ti)(ti)(ti)(ti)轉(zhuan)換為(wei)奧氏體(ti)(ti)(ti)(ti)(ti)，并有部分(fen)球狀石墨(mo)(mo)溶解于奧氏體(ti)(ti)(ti)(ti)(ti)，經(jing)保溫(wen)(wen)后空冷(leng)奧氏體(ti)(ti)(ti)(ti)(ti)轉(zhuan)變為(wei)細珠(zhu)光體(ti)(ti)(ti)(ti)(ti)，因(yin)此鑄(zhu)件(jian)的(de)(de)(de)強度(du)(du)提高。