點焊工件只在有限的接觸面上即所謂“點”上被焊接起來，并形成扁球形的熔核。點焊又分為單點焊和多點焊，多點焊時使用兩對以上的電極，在同一工序內形成多個熔核。點焊方法通常又分為雙面點焊和單面點焊兩大類。雙面點焊時，通常采用搭接接頭和折邊接頭兩種形式（圖6-11).接頭可以由兩個或兩個以上等厚度或不等厚度的工件組成。在設計點焊結構時，必須考慮電極的可達性，即電極必須能方便地抵達構件的焊接部位。同時還應考慮邊距、搭接量、點距、裝配間隔和焊點強度等因素。

  由于不銹鋼的電阻率高、導熱性差，因此與低碳鋼相比，可采用較小的焊接電流和較短的焊接時間。不銹鋼有較高的高溫強度，必須采用較高的電極壓力，以防止產生縮孔、裂紋等缺陷。不銹鋼的熱敏感性強，通常采用較短的焊接時間、強有力的內部和外部水冷卻，并且要準確地控制加熱時間和焊接電流，以防熱影響區晶粒長大和出現晶間腐蝕現象。點焊不銹鋼的電極推薦用硬度較高的電極合金，滿足高電極壓力的需要。

  馬氏體不銹鋼由于(yu)有淬(cui)(cui)火(huo)(huo)傾向，點(dian)焊(han)(han)(han)時要求(qiu)采用(yong)較長(chang)焊(han)(han)(han)接(jie)時間。為消除淬(cui)(cui)硬組(zu)織，最好采用(yong)焊(han)(han)(han)后回火(huo)(huo)的雙脈(mo)沖點(dian)焊(han)(han)(han)。點(dian)焊(han)(han)(han)時一般不采用(yong)電極的外部水冷卻，以免因淬(cui)(cui)火(huo)(huo)而產生裂紋。

  單(dan)(dan)面(mian)(mian)(mian)點(dian)(dian)(dian)(dian)(dian)焊(han)(han)時(shi)，電(dian)(dian)極(ji)由工(gong)件(jian)的(de)(de)(de)同一(yi)側向焊(han)(han)接(jie)(jie)處饋電(dian)(dian)。典型的(de)(de)(de)單(dan)(dan)面(mian)(mian)(mian)點(dian)(dian)(dian)(dian)(dian)焊(han)(han)方式如(ru)圖(tu)6-12所示。圖(tu)中(zhong)：（a)單(dan)(dan)面(mian)(mian)(mian)單(dan)(dan)點(dian)(dian)(dian)(dian)(dian)點(dian)(dian)(dian)(dian)(dian)焊(han)(han)，不(bu)形成(cheng)焊(han)(han)點(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)電(dian)(dian)極(ji)采(cai)用大(da)直徑和大(da)接(jie)(jie)觸(chu)面(mian)(mian)(mian)以減小電(dian)(dian)流密度。（b)無分流的(de)(de)(de)單(dan)(dan)面(mian)(mian)(mian)雙點(dian)(dian)(dian)(dian)(dian)點(dian)(dian)(dian)(dian)(dian)焊(han)(han)，此時(shi)焊(han)(han)接(jie)(jie)電(dian)(dian)流全(quan)部流經(jing)焊(han)(han)接(jie)(jie)區(qu)。（c)有(you)分流的(de)(de)(de)單(dan)(dan)面(mian)(mian)(mian)雙點(dian)(dian)(dian)(dian)(dian)點(dian)(dian)(dian)(dian)(dian)焊(han)(han)，流經(jing)上面(mian)(mian)(mian)工(gong)件(jian)的(de)(de)(de)電(dian)(dian)流不(bu)經(jing)過焊(han)(han)接(jie)(jie)區(qu)，形成(cheng)分流。為了(le)給焊(han)(han)接(jie)(jie)電(dian)(dian)流提供低電(dian)(dian)阻的(de)(de)(de)通路。在工(gong)件(jian)下面(mian)(mian)(mian)墊(dian)有(you)銅(tong)墊(dian)板。（d)當兩焊(han)(han)點(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)間距(ju)很大(da)，如(ru)在進(jin)行(xing)骨架構件(jian)和復板的(de)(de)(de)焊(han)(han)接(jie)(jie)時(shi)，為了(le)避免不(bu)適當的(de)(de)(de)加(jia)熱(re)引(yin)起翹曲和減小兩電(dian)(dian)極(ji)間電(dian)(dian)阻，采(cai)用了(le)特殊的(de)(de)(de)銅(tong)橋(qiao)A,與電(dian)(dian)極(ji)同時(shi)壓緊在工(gong)件(jian)上。