家用電器不銹(xiu)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(ji)
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)衣(yi)機加工(gong)(gong)時(shi)使(shi)(shi)用(yong)(yong)(yong)厚度0.5mm或(huo)0.6mm的(de)不銹鋼(gang)薄(bo)(bo)板(ban),采(cai)(cai)(cai)用(yong)(yong)(yong)焊(han)接(jie)方(fang)(fang)法(fa)或(huo)是(shi)鉚(liu)接(jie)方(fang)(fang)法(fa)制(zhi)造。洗(xi)滌(di)桶(tong)的(de)中間桶(tong)體(ti)可以采(cai)(cai)(cai)用(yong)(yong)(yong)不銹鋼(gang)卷材(cai)或(huo)板(ban)材(cai)采(cai)(cai)(cai)用(yong)(yong)(yong)壓(ya)沖(chong)工(gong)(gong)藝進行(xing)連續(xu)(xu)加工(gong)(gong)業。為脫水而(er)設(she)置許多小(xiao)孔,使(shi)(shi)用(yong)(yong)(yong)沖(chong)床(chuang)的(de)沖(chong)頭(tou)(凸模)進行(xing)沖(chong)孔,為了(le)使(shi)(shi)洗(xi)滌(di)物不被劃傷,要(yao)(yao)施行(xing)去毛(mao)刺工(gong)(gong)序(xu),將所有沖(chong)孔的(de)毛(mao)刺、銳邊(bian)、尖(jian)角去除,然后(hou)壓(ya)制(zhi)出像洗(xi)衣(yi)板(ban)樣的(de)凸點,接(jie)著進行(xing)桶(tong)體(ti)卷圓成形。對接(jie)部分(fen)采(cai)(cai)(cai)用(yong)(yong)(yong)TIG焊(han)接(jie)方(fang)(fang)式(shi)(shi)和鉚(liu)接(jie)方(fang)(fang)式(shi)(shi)進行(xing)連接(jie)。然后(hou),桶(tong)腹部的(de)上沿其邊(bian)緣(yuan)(yuan)要(yao)(yao)進行(xing)卷邊(bian),使(shi)(shi)其形成圓形邊(bian)緣(yuan)(yuan)。下部分(fen)則(ze)要(yao)(yao)和不銹鋼(gang)桶(tong)底相接(jie)合。不銹鋼(gang)桶(tong)底,采(cai)(cai)(cai)用(yong)(yong)(yong)鉚(liu)接(jie)方(fang)(fang)式(shi)(shi)較多。鉚(liu)接(jie)方(fang)(fang)式(shi)(shi)有如上所述(shu)幾種加工(gong)(gong)工(gong)(gong)序(xu),為了(le)防止產(chan)生(sheng)毛(mao)刺、銳角或(huo)尖(jian)邊(bian),加工(gong)(gong)時(shi)需要(yao)(yao)潤滑,大多數是(shi)采(cai)(cai)(cai)用(yong)(yong)(yong)在不銹鋼(gang)薄(bo)(bo)板(ban)上貼附表(biao)面(mian)保(bao)護薄(bo)(bo)膜的(de)狀(zhuang)態(tai)下,進行(xing)加工(gong)(gong)。但是(shi),如采(cai)(cai)(cai)用(yong)(yong)(yong)TIG焊(han)接(jie)方(fang)(fang)式(shi)(shi),因表(biao)面(mian)保(bao)護薄(bo)(bo)膜而(er)不利于焊(han)接(jie),可改用(yong)(yong)(yong)在焊(han)接(jie)過程(cheng)中自行(xing)揮(hui)發(fa)狀(zhuang)態(tai)的(de)揮(hui)發(fa)性加工(gong)(gong)油,以實現連續(xu)(xu)性批量生(sheng)產(chan)。采(cai)(cai)(cai)用(yong)(yong)(yong)TIG焊(han)接(jie)方(fang)(fang)式(shi)(shi)的(de)焊(han)接(jie)速度是(shi)產(chan)量和生(sheng)產(chan)成本(ben)的(de)關(guan)鍵工(gong)(gong)序(xu)。
滾筒式洗滌干燥機,由于(yu)具有(you)干燥功(gong)能(neng),要進(jin)行加熱干燥,所(suo)以(yi)(yi)必(bi)須(xu)使(shi)用不銹(xiu)(xiu)鋼(gang)桶。因不銹(xiu)(xiu)鋼(gang)桶是雙層結構,所(suo)以(yi)(yi)一臺不銹(xiu)(xiu)鋼(gang)用量(liang)相當于(yu)原來的2臺以(yi)(yi)上(shang)。在選定(ding)材料和(he)加工方(fang)法方(fang)面(mian),基本上(shang)和(he)上(shang)述全自動洗滌機類(lei)似。
2. 電熱水器(qi)
制作不(bu)(bu)銹(xiu)(xiu)鋼熱水罐曾沿用06Cr19Ni10(304),但(dan)(dan)多次發生應力腐蝕(shi)開裂問題。鐵(tie)素體(ti)系列不(bu)(bu)銹(xiu)(xiu)鋼019Cr19Mo2NbTi(444),對防(fang)止應力腐蝕(shi)開裂是一種完美對策。雖(sui)然使用鐵(tie)素體(ti)系列不(bu)(bu)銹(xiu)(xiu)鋼,但(dan)(dan)熱水罐上下封頭與筒體(ti)接合處(chu)仍有零星間隙腐蝕(shi)發生,加(jia)強焊(han)接質(zhi)量及接合部間隙的管理問題即可解決。
裝配間(jian)(jian)隙過于(yu)狹(xia)窄是造成(cheng)間(jian)(jian)隙腐蝕(shi)(shi)的(de)(de)原因。所以有(you)必要適當加大裝配間(jian)(jian)隙。對回收的(de)(de)舊電(dian)熱水(shui)器熱水(shui)罐(guan)內部(bu)(bu)進行調查,由于(yu)使(shi)(shi)用了019Cr19Mo2NbTi(444)而使(shi)(shi)熱水(shui)罐(guan)內部(bu)(bu)幾乎(hu)沒有(you)腐蝕(shi)(shi),質量(liang)事故多使(shi)(shi)其他(ta)零部(bu)(bu)件(jian)損壞(huai)而不能使(shi)(shi)用。可(ke)以說(shuo),電(dian)熱水(shui)器筒(tong)體(ti)的(de)(de)不銹(xiu)鋼化(hua),是“機能材料選定”最適合的(de)(de)產品。
加(jia)工方面:上(shang)、下封(feng)頭使用(yong)(yong)厚度為1.0~1.2mm的不銹(xiu)鋼薄板,沖壓(ya)而(er)成。筒(tong)體(ti)選用(yong)(yong)0.6~0.8mm的不銹(xiu)鋼薄板,采用(yong)(yong)TIG焊接。考慮(lv)到(dao)熱(re)水(shui)器上(shang)部(bu)(bu)因水(shui)位高低的變(bian)化,使得氣相(xiang)和(he)液相(xiang)在上(shang)部(bu)(bu)反復交替變(bian)化,進(jin)而(er)氯(lv)離子濃度在逐(zhu)漸變(bian)濃,易產生腐蝕(shi),所以(yi)上(shang)部(bu)(bu)的焊縫應(ying)從內部(bu)(bu)焊接。
圖6-5是熱水器內(nei)結構膽示(shi)意圖及可能出現(xian)腐蝕。
熱(re)水器內膽加工工藝流程:下料→沖壓封(feng)頭→加工出入水孔(kong)→卷筒(tong)(tong)→焊(han)(han)接筒(tong)(tong)體(ti)→焊(han)(han)接上(shang)下封(feng)頭→耐(nai)壓檢驗。