家用電器不銹鋼化的首要問題就是可能會增加成本。即便如此,全自動不銹鋼桶洗衣機、滾筒式洗滌干燥機由于其清潔性,耐用性銷售量爆發式大增,繼而家用電器全部不銹鋼化,就連衣類干燥機也由表面處理鋼板改為不銹鋼。
1. 洗衣機
無論何種洗衣機都是要和水接觸,因此大多數洗衣機都是先用不銹鋼的代表鋼種06Cr19Ni10(304)。也可以選用0022Cr18Ti(439)、019Cr17MoNb(436L)等可進行深度拉深的鋼種,可作為洗衣機的首選鋼種。它在制造洗衣機洗滌桶時,無論是采用焊接結構或是鉚接結構,均可以確保有足夠的耐腐蝕性能。
洗(xi)(xi)衣機加(jia)(jia)工(gong)(gong)(gong)(gong)(gong)時使(shi)(shi)(shi)用(yong)厚度0.5mm或(huo)0.6mm的(de)不(bu)(bu)銹(xiu)鋼(gang)(gang)薄板,采(cai)(cai)用(yong)焊(han)接(jie)(jie)(jie)(jie)(jie)方(fang)(fang)(fang)法或(huo)是鉚(liu)接(jie)(jie)(jie)(jie)(jie)方(fang)(fang)(fang)法制造。洗(xi)(xi)滌桶(tong)(tong)的(de)中(zhong)間桶(tong)(tong)體可以(yi)采(cai)(cai)用(yong)不(bu)(bu)銹(xiu)鋼(gang)(gang)卷材(cai)或(huo)板材(cai)采(cai)(cai)用(yong)壓沖(chong)(chong)工(gong)(gong)(gong)(gong)(gong)藝(yi)進(jin)行(xing)(xing)連續加(jia)(jia)工(gong)(gong)(gong)(gong)(gong)業。為(wei)脫水而(er)設(she)置許多(duo)(duo)小孔,使(shi)(shi)(shi)用(yong)沖(chong)(chong)床的(de)沖(chong)(chong)頭(tou)(凸(tu)模)進(jin)行(xing)(xing)沖(chong)(chong)孔,為(wei)了使(shi)(shi)(shi)洗(xi)(xi)滌物(wu)不(bu)(bu)被劃(hua)傷,要施行(xing)(xing)去毛(mao)刺(ci)(ci)工(gong)(gong)(gong)(gong)(gong)序(xu),將所有沖(chong)(chong)孔的(de)毛(mao)刺(ci)(ci)、銳(rui)邊、尖角(jiao)去除,然(ran)后壓制出像洗(xi)(xi)衣板樣的(de)凸(tu)點(dian),接(jie)(jie)(jie)(jie)(jie)著進(jin)行(xing)(xing)桶(tong)(tong)體卷圓成形。對接(jie)(jie)(jie)(jie)(jie)部分采(cai)(cai)用(yong)TIG焊(han)接(jie)(jie)(jie)(jie)(jie)方(fang)(fang)(fang)式(shi)和(he)鉚(liu)接(jie)(jie)(jie)(jie)(jie)方(fang)(fang)(fang)式(shi)進(jin)行(xing)(xing)連接(jie)(jie)(jie)(jie)(jie)。然(ran)后,桶(tong)(tong)腹部的(de)上(shang)沿其(qi)邊緣要進(jin)行(xing)(xing)卷邊,使(shi)(shi)(shi)其(qi)形成圓形邊緣。下(xia)部分則要和(he)不(bu)(bu)銹(xiu)鋼(gang)(gang)桶(tong)(tong)底相(xiang)接(jie)(jie)(jie)(jie)(jie)合。不(bu)(bu)銹(xiu)鋼(gang)(gang)桶(tong)(tong)底,采(cai)(cai)用(yong)鉚(liu)接(jie)(jie)(jie)(jie)(jie)方(fang)(fang)(fang)式(shi)較(jiao)多(duo)(duo)。鉚(liu)接(jie)(jie)(jie)(jie)(jie)方(fang)(fang)(fang)式(shi)有如上(shang)所述幾種(zhong)加(jia)(jia)工(gong)(gong)(gong)(gong)(gong)工(gong)(gong)(gong)(gong)(gong)序(xu),為(wei)了防止(zhi)產生(sheng)(sheng)毛(mao)刺(ci)(ci)、銳(rui)角(jiao)或(huo)尖邊,加(jia)(jia)工(gong)(gong)(gong)(gong)(gong)時需要潤滑,大(da)多(duo)(duo)數是采(cai)(cai)用(yong)在不(bu)(bu)銹(xiu)鋼(gang)(gang)薄板上(shang)貼附表面(mian)保護薄膜的(de)狀(zhuang)態下(xia),進(jin)行(xing)(xing)加(jia)(jia)工(gong)(gong)(gong)(gong)(gong)。但是,如采(cai)(cai)用(yong)TIG焊(han)接(jie)(jie)(jie)(jie)(jie)方(fang)(fang)(fang)式(shi),因表面(mian)保護薄膜而(er)不(bu)(bu)利(li)于焊(han)接(jie)(jie)(jie)(jie)(jie),可改用(yong)在焊(han)接(jie)(jie)(jie)(jie)(jie)過程(cheng)中(zhong)自行(xing)(xing)揮發(fa)狀(zhuang)態的(de)揮發(fa)性加(jia)(jia)工(gong)(gong)(gong)(gong)(gong)油(you),以(yi)實現連續性批量(liang)生(sheng)(sheng)產。采(cai)(cai)用(yong)TIG焊(han)接(jie)(jie)(jie)(jie)(jie)方(fang)(fang)(fang)式(shi)的(de)焊(han)接(jie)(jie)(jie)(jie)(jie)速度是產量(liang)和(he)生(sheng)(sheng)產成本(ben)的(de)關鍵工(gong)(gong)(gong)(gong)(gong)序(xu)。
滾(gun)筒(tong)式洗滌干(gan)(gan)燥機,由于(yu)具有干(gan)(gan)燥功(gong)能,要進行加熱干(gan)(gan)燥,所(suo)以必(bi)須(xu)使(shi)用(yong)不銹(xiu)鋼(gang)桶。因不銹(xiu)鋼(gang)桶是雙層結構,所(suo)以一(yi)臺不銹(xiu)鋼(gang)用(yong)量相當于(yu)原來的2臺以上(shang)。在(zai)選定材料(liao)和加工方(fang)法方(fang)面,基本上(shang)和上(shang)述全自動(dong)洗滌機類(lei)似。
2. 電熱水器
制(zhi)作不(bu)銹(xiu)鋼熱(re)水罐曾沿用(yong)06Cr19Ni10(304),但多次發(fa)生應力腐(fu)(fu)蝕(shi)開裂(lie)問題。鐵素體系(xi)列不(bu)銹(xiu)鋼019Cr19Mo2NbTi(444),對防止應力腐(fu)(fu)蝕(shi)開裂(lie)是一種完(wan)美對策。雖然(ran)使用(yong)鐵素體系(xi)列不(bu)銹(xiu)鋼,但熱(re)水罐上下(xia)封(feng)頭(tou)與筒(tong)體接(jie)合處仍(reng)有零星間(jian)隙腐(fu)(fu)蝕(shi)發(fa)生,加強焊接(jie)質(zhi)量及接(jie)合部間(jian)隙的管理問題即可(ke)解決。
裝配(pei)間隙過于(yu)狹(xia)窄是造成間隙腐蝕的原(yuan)因(yin)。所以有(you)必要(yao)適當加大裝配(pei)間隙。對(dui)回收的舊電熱水器(qi)熱水罐(guan)內部進(jin)行調查,由于(yu)使用了019Cr19Mo2NbTi(444)而使熱水罐(guan)內部幾乎沒有(you)腐蝕,質(zhi)量事故多使其(qi)他零部件損壞而不能使用。可(ke)以說,電熱水器(qi)筒體的不銹鋼化,是“機能材料(liao)選定”最適合的產品。
加工方面:上、下(xia)封頭(tou)使(shi)用(yong)(yong)厚度為1.0~1.2mm的(de)不銹鋼(gang)薄(bo)板(ban),沖壓而成。筒體選用(yong)(yong)0.6~0.8mm的(de)不銹鋼(gang)薄(bo)板(ban),采用(yong)(yong)TIG焊(han)接(jie)。考(kao)慮(lv)到熱水器上部(bu)(bu)因水位高低的(de)變化,使(shi)得氣(qi)相和(he)液相在(zai)(zai)上部(bu)(bu)反復交替變化,進而氯離子濃度在(zai)(zai)逐(zhu)漸變濃,易產(chan)生腐蝕,所以(yi)上部(bu)(bu)的(de)焊(han)縫應從(cong)內(nei)部(bu)(bu)焊(han)接(jie)。
圖(tu)6-5是(shi)熱水(shui)器內結(jie)構膽示意圖(tu)及可能出(chu)現腐蝕。
熱水器內膽(dan)加(jia)工工藝(yi)流程:下料→沖壓封頭(tou)→加(jia)工出入水孔→卷筒→焊接(jie)(jie)筒體→焊接(jie)(jie)上下封頭(tou)→耐壓檢驗。