904L耐酸鋼#不銹鋼板 904L低碳高鎳
Super austenitic steel 904 l, 904 l stainless steel is a low carbon high nickel, molybdenum, 904 l austenitic stainless acid-resistant steel proprietary material for h. S company in France. Has the very good activation - passivation shift ability, excellent corrosion resistance, in the oxidizing acid such as sulfuric acid, acetic acid, formic acid, phosphoric acid have good corrosion resistance of 904 l steel plate, in neutral medium containing chloride ions has the very good resistance to pitting corrosion, and has good resistance crevice corrosion and stress corrosion resistance. Applicable to various concentrations of sulphuric acid under 70 ℃, under ordinary conditions of pressure resistance to any concentration, temperature of acetic acid and formic acid and acetic acid in mixed acid corrosion resistance is very good also. A low carbon high alloy austenitic stainless steel, in the dilute sulphuric acid have good corrosion resistance, specially designed for harsh environment corrosion conditions. With high content of chromium and nickel content enough, the addition of copper make it has strong acid resistance, especially for chloride clearance corrosion and stress corrosion cracking are highly resistant, not easy to appear pitting spots and cracks
904L超級馬氏體不銹鋼典型的基體金屬顯微組織為回火馬氏體。這種低碳回火馬氏體組織具有很高的強度和韌性。根據含鎳量的不同、熱處理條件的差異，一些牌號的超級馬氏體不銹鋼基體顯微組織中可能會出現10%～40%的細小彌散狀殘留奧氏體。對于含鉻16%等級的超級馬氏體不銹鋼，顯微組織中可能出現少量的δ鐵素體。為了獲得理想的細晶粒回火馬氏體，在鋼板交貨之前一般都經過淬火加回火處理。
屈服應力：б0.2為550～850MPa
抗拉強度：бb＞520MPa
沖擊強度：≥50焦耳
延伸率：δ≥35%
機械性能：馬氏體不銹鋼含鉻13%，由于鐵素體晶粒在焊接過程中粗化和硬化，而使其可焊性很差。以往，這類不銹鋼的用途嚴格限制于非焊接零件的安裝。經過冶煉工藝的不斷改進，降低了馬氏體不銹鋼中的碳、氮、硫含量，又增加了一定量的鎳（zui高含量達6.5%）和鉬（zui高含量2.5%），從而開發出了超級馬氏體不銹鋼。這種材料在加工制造過程中又采取了特殊的工藝措施，使得新的超級馬氏體不銹鋼的焊接性能大大超過了傳統的馬氏體不銹鋼。
