Pfeiffer 博士曾經在一篇文章中稱:“若要探討1886年后無縫亞洲歐美色綜合一區二區在線:不銹鋼管生產技術的發展,就會發現這一技術沿著兩個方向在發展:一方面是斜軋穿孔和延伸技術的多樣化的發展;另一方面是Heinrich Ehrhardt 研究的水壓沖孔工藝的發展,Ehrhardt于1899年在他的 Dusseldorf的 Reisholz 建立了頂管工廠。”當時,Ehrhardt從曼氏兄弟初期所遇到的困難中吸取教訓,他研制出的水壓沖孔工藝,對管坯質量的要求沒有斜軋穿孔工藝那么高,環式孔型頂管工藝基本上是拔制工藝,因此Ehrhardt軋管工藝是完全不同于曼內斯曼穿孔工藝的另一條途徑。
在(zai)19世(shi)紀80年(nian)代艾(ai)哈德(de)(de)(de)也曾發(fa)(fa)現(xian)圓鋼(gang)斜軋時(shi)工(gong)(gong)(gong)(gong)件(jian)中心(xin)發(fa)(fa)生(sheng)(sheng)撕裂,產(chan)(chan)(chan)生(sheng)(sheng)孔腔的(de)現(xian)象,但是他對這一現(xian)象不(bu)夠敏(min)感,后來只好(hao)另(ling)辟蹊徑,發(fa)(fa)展另(ling)一種生(sheng)(sheng)產(chan)(chan)(chan)空(kong)心(xin)坯(pi)(pi)的(de)工(gong)(gong)(gong)(gong)藝(yi),在(zai)1891年(nian)發(fa)(fa)明(ming)了(le)水(shui)(shui)壓沖(chong)孔工(gong)(gong)(gong)(gong)藝(yi),比曼內斯曼兄弟發(fa)(fa)明(ming)斜軋穿(chuan)孔晚(wan)了(le)6年(nian),通常所講的(de)“艾(ai)哈德(de)(de)(de)工(gong)(gong)(gong)(gong)藝(yi)”(Ehrhardt Process)乃(nai)由(you)水(shui)(shui)壓沖(chong)孔和頂(ding)管(guan)延伸兩個工(gong)(gong)(gong)(gong)藝(yi)過(guo)程組成。1893年(nian)初艾(ai)哈德(de)(de)(de)在(zai)德(de)(de)(de)文(wen)(wen)《鋼(gang)與鐵(tie)》雜志上(shang)發(fa)(fa)表(biao)文(wen)(wen)章稱:水(shui)(shui)壓沖(chong)孔工(gong)(gong)(gong)(gong)藝(yi)是生(sheng)(sheng)產(chan)(chan)(chan)空(kong)心(xin)坯(pi)(pi)的(de)新工(gong)(gong)(gong)(gong)藝(yi),它與斜軋穿(chuan)孔工(gong)(gong)(gong)(gong)藝(yi)截(jie)然不(bu)同,它對不(bu)銹(xiu)鋼(gang)管(guan)坯(pi)(pi)質量的(de)要求沒有斜軋穿(chuan)孔工(gong)(gong)(gong)(gong)藝(yi)那么高。采(cai)用頂(ding)管(guan)環頂(ding)制無(wu)縫不(bu)銹(xiu)鋼(gang)管(guan)的(de)工(gong)(gong)(gong)(gong)藝(yi)則(ze)要發(fa)(fa)明(ming)得晚(wan)一些,艾(ai)哈德(de)(de)(de)是在(zai)1899年(nian)在(zai)杜市的(de)Reisholz地方建立Rheinmetall工(gong)(gong)(gong)(gong)廠(chang)時(shi)采(cai)用頂(ding)管(guan)環以延伸沖(chong)孔坯(pi)(pi),由(you)此正(zheng)式(shi)誕(dan)生(sheng)(sheng)了(le)艾(ai)哈德(de)(de)(de)工(gong)(gong)(gong)(gong)藝(yi),亦(yi)即頂(ding)管(guan)工(gong)(gong)(gong)(gong)藝(yi)。他在(zai)1902年(nian)的(de)德(de)(de)(de)國(guo)(guo)鋼(gang)鐵(tie)工(gong)(gong)(gong)(gong)程師年(nian)會上(shang)發(fa)(fa)表(biao)論(lun)文(wen)(wen),闡述艾(ai)哈德(de)(de)(de)工(gong)(gong)(gong)(gong)藝(yi)的(de)技術(shu)內涵(han),并在(zai)英美兩國(guo)(guo)申(shen)請了(le)專利。
艾哈德(de)在(zai)(zai)杜(du)市Reisholz 區建立(li)不銹鋼管(guan)廠與(yu)德(de)國海軍部的(de)訂貨(huo)有關(guan),德(de)國海軍部于1898年2月提出(chu)一份無(wu)縫不銹鋼管(guan)訂貨(huo)單,由于數量大,而且要求交貨(huo)時間(jian)緊,因此(ci)海軍部明確表示位于杜(du)市的(de)曼內斯(si)曼鋼管(guan)公司和 Rheinmetall工廠都參(can)與(yu)生(sheng)產(chan),艾哈德(de)原來采用穿孔(kong)和熱拔相結合(he)的(de)辦(ban)法生(sheng)產(chan)鋼管(guan),他(ta)接受這份訂單后,就(jiu)在(zai)(zai)Reisholz建立(li)不銹鋼管(guan)廠,在(zai)(zai)水壓沖孔(kong)工藝的(de)基礎上(shang)添加空心坯延伸工藝即(ji)采用頂管(guan)坯的(de)頂管(guan)工藝,于是誕生(sheng)了完(wan)整的(de)艾哈德(de)工藝。