（1）工(gong)程(cheng)機械(xie)使(shi)用(yong)(yong)初期(qi)階段(duan)的(de)故(gu)障(zhang)(zhang)特點。工(gong)程(cheng)機械(xie)在(zai)使(shi)用(yong)(yong)初期(qi)(相當于走合(he)期(qi))其故(gu)障(zhang)(zhang)是(shi)(shi)(shi)由高(gao)到低(降(jiang)曲線(xian))，使(shi)用(yong)(yong)初期(qi)故(gu)障(zhang)(zhang)率(lv)高(gao)低是(shi)(shi)(shi)隨制造(zao)或維修質量和走合(he)時期(qi)的(de)使(shi)用(yong)(yong)有(you)關．如果工(gong)程(cheng)機械(xie)制造(zao)或修理質量高(gao)，并能正確(que)地(di)使(shi)用(yong)(yong)與維護。那(nei)么，初期(qi)故(gu)障(zhang)(zhang)率(lv)就低。否則早期(qi)故(gu)障(zhang)(zhang)率(lv)會高(gao)。早期(qi)故(gu)障(zhang)(zhang)多地(di)是(shi)(shi)(shi)聯(lian)接(jie)螺栓(shuan)松(song)(song)動或松(song)(song)脫(tuo)；管道接(jie)頭松(song)(song)動或松(song)(song)脫(tuo)：殘留金屬屑(xie)或鑄(zhu)造(zao)砂易堵(du)塞油道或夾在(zai)相對運動摩擦中拉傷機件(jian)(jian)(如液壓(ya)系統中的(de)執(zhi)行機構油缸(gang))造(zao)成漏(lou)油，調整(zheng)后的(de)間隙或壓(ya)力發生變化，使(shi)機件(jian)(jian)不能執(zhi)行規定能力，有(you)些(xie)接(jie)合(he)因螺栓(shuan)不緊而漏(lou)水、漏(lou)油、漏(lou)氣等。

（2）工程(cheng)機械(xie)正(zheng)常(chang)使(shi)用階段(duan)的(de)故(gu)障特點。工程(cheng)機械(xie)走合期結束后，進人正(zheng)常(chang)使(shi)用階段(duan)。工程(cheng)機械(xie)在這個階段(duan)內運(yun)行(xing)，只要按規定維護和正(zheng)確使(shi)用，一般不(bu)會(hui)發生故(gu)障，即(ji)便發生故(gu)障，也是隨機性的(de)故(gu)障。