日期:2024-11-24 23:52
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摘要:<span style="font-family:宋體;font-size:small;"> </span>
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<span style="font-size:small;"><span style="font-family:"Times New Roman";"><span lang="EN-US">304</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">不銹鋼角鋼拉深會出現哪些問題?</span></span>
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<span style="font-size:small;"><span style="font-family:"Times New Roman";"><span lang="EN-US">304</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">不銹鋼角鋼的延展率小、彈性模量</span><span style="font-family:"Times New Roman";"><span lang="EN-US">E</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">較大</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">硬化指數較高</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">厚向異性指數</span><span style="font-family:"Times New Roman";"><span lang="EN-US">r</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">值很小</span><span style="font-family:"Times New Roman";"><span lang="EN-US">(304</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">不銹鋼角鋼為</span><span style="font-family:"Times New Roman";"><span lang="EN-US">0.9~0.11,</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">軟鋼為</span><span style="font-family:"Times New Roman";"><span lang="EN-US">1.3~2.0).304</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">不銹鋼角鋼材料由屈服到破裂的塑性變形階段短</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">特別是它的塑性應變比的加權值</span><span style="font-family:"Times New Roman";"><span lang="EN-US">R</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">較大</span><span style="font-family:"Times New Roman";"><span lang="EN-US">.304</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">不銹鋼角鋼板拉深開裂有時發生在拉深變形之后</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">有時是在當拉深件由凹模內退出時立即發生</span><span style="font-family:"Times New Roman";"><span lang="EN-US">;</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">有時是在拉深變形后受撞擊或振動時發生</span><span style="font-family:"Times New Roman";"><span lang="EN-US">;</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">也有時在拉深變形后經過一段時間的存放或在使用過程中才發生</span><span style="font-family:"Times New Roman";"><span lang="EN-US">.</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">本文針對</span><span style="font-family:"Times New Roman";"><span lang="EN-US">304</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">不銹鋼角鋼板拉深時產生缺陷的原因進行了分析</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">并提出解決措施</span><span lang="EN-US"><span style="font-family:"Times New Roman";">.</span></span></span>
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<span style="font-size:small;"><span style="font-family:"Times New Roman";"><span lang="EN-US">1</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">、機械性能檢驗</span></span>
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<span style="font-size:small;"><span style="font-family:"Times New Roman";"><span lang="EN-US">(1)</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">檢驗方法:</span></span>
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<span style="font-size:small;"><span style="font-family:"Times New Roman";"><span lang="EN-US">a.</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">拉伸試驗方法。常用的標準檢驗方法有</span><span style="font-family:"Times New Roman";"><span lang="EN-US">GB/T228-87</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">JISZ2201</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">JISZ2241</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">ASTM A370</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">DIN50145</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">等</span><span lang="EN-US"><span style="font-family:"Times New Roman";">;</span></span></span>
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<span style="font-size:small;"><span style="font-family:"Times New Roman";"><span lang="EN-US">b.</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">彎曲試驗方法。常用的標準檢驗方法有</span><span style="font-family:"Times New Roman";"><span lang="EN-US">GB/T232-88</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">JISZ2204</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">JISZ2248</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">ASTM E290</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">DIN50111</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">等。</span></span>
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<span style="font-size:small;"><span style="font-family:"Times New Roman";"><span lang="EN-US">(2)</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">性能指標:考核不銹鋼扁鋼性能的檢驗項目主要為拉伸試驗和彎曲試驗。指標包括屈服點、抗拉強度、延伸率及彎曲合格等項。</span></span>
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<span style="font-size:small;"><span style="font-family:"Times New Roman";"><span lang="EN-US">2</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">、開裂形成的原因</span></span>
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<span style="font-size:small;"><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">奧氏體</span><span style="font-family:"Times New Roman";"><span lang="EN-US">304</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">不銹鋼角鋼的冷作硬化指數高</span><span style="font-family:"Times New Roman";"><span lang="EN-US">(304</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">不銹鋼角鋼為</span><span style="font-family:"Times New Roman";"><span lang="EN-US">0.34).</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">奧氏體</span><span style="font-family:"Times New Roman";"><span lang="EN-US">304</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">不銹鋼角鋼為亞穩定型</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">在變形時會發生相變</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">誘發馬氏體相</span><span style="font-family:"Times New Roman";"><span lang="EN-US">.</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">馬氏體相較脆</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">因此容易發生開裂</span><span style="font-family:"Times New Roman";"><span lang="EN-US">.</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">在塑性變形時</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">隨著變形量的增大</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">誘發的馬氏體含量也將隨著變形量的增大而增高</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">殘余應力也越大</span><span style="font-family:"Times New Roman";"><span lang="EN-US">.</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">殘余應力與馬氏體含量的關系</span></span>
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<span style="font-size:small;"><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">誘發的馬氏體相含量越高</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">引起的殘余應力也越大</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">在加工過程中也就越易開裂</span><span lang="EN-US"><span style="font-family:"Times New Roman";">.</span></span></span>
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<span style="font-size:small;"><span style="font-family:"Times New Roman";"><span lang="EN-US">3</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">、表面劃痕形成的原因</span></span>
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<span style="font-size:small;"><span style="font-family:"Times New Roman";"><span lang="EN-US">304</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">不銹鋼角鋼拉深件表面出現劃痕主要是由于工件和模具表面存在相對移動</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">在一定壓力的作用下</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">致使坯料與模具局部表面直接產生摩擦</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">加之坯料的變形熱使坯料及金屬屑熔敷在模具表面上</span><span style="font-family:"Times New Roman";"><span lang="EN-US">,</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">使工件表面擦傷產生劃痕</span></span>
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<span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";"><span style="font-size:small;">進出口不銹鋼角鋼的定貨一般以使用中所要求的規格為主,其鋼號為相應的碳結鋼鋼號。也即不銹鋼角鋼除了規格號之外,沒有特定的成分和性能系列。</span></span>
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<span style="font-size:small;"><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">不銹鋼角鋼的交貨長度分定尺、倍尺兩種,國產不銹鋼角鋼的定尺選擇范圍根據規格號的不同有</span><span style="font-family:"Times New Roman";"><span lang="EN-US">3—9m</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">4—12m</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">4—19m</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">、</span><span style="font-family:"Times New Roman";"><span lang="EN-US">6—19m</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">四個范圍。日本產不銹鋼角鋼的長度選擇范圍為</span><span style="font-family:"Times New Roman";"><span lang="EN-US">6—15m</span></span><span style="font-family:宋體;mso-ascii-font-family:"mso-hansi-font-family:";">。</span></span>
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<span lang="EN-US"><span style="font-family:"Times New Roman";font-size:small;"> </span></span>
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304不銹鋼角鋼拉深會出現哪些問題?
304不銹鋼角鋼的延展率小、彈性模量E較大,硬化指數較高,厚向異性指數r值很小(304不銹鋼角鋼為0.9~0.11,軟鋼為1.3~2.0).304不銹鋼角鋼材料由屈服到破裂的塑性變形階段短,特別是它的塑性應變比的加權值R較大.304不銹鋼角鋼板拉深開裂有時發生在拉深變形之后,有時是在當拉深件由凹模內退出時立即發生;有時是在拉深變形后受撞擊或振動時發生;也有時在拉深變形后經過一段時間的存放或在使用過程中才發生.本文針對304不銹鋼角鋼板拉深時產生缺陷的原因進行了分析,并提出解決措施.
1、機械性能檢驗
(1)檢驗方法:
a.拉伸試驗方法。常用的標準檢驗方法有GB/T228-87、JISZ2201、JISZ2241、ASTM A370、DIN50145等;
b.彎曲試驗方法。常用的標準檢驗方法有GB/T232-88、JISZ2204、JISZ2248、ASTM E290、DIN50111等。
(2)性能指標:考核不銹鋼扁鋼性能的檢驗項目主要為拉伸試驗和彎曲試驗。指標包括屈服點、抗拉強度、延伸率及彎曲合格等項。
2、開裂形成的原因
奧氏體304不銹鋼角鋼的冷作硬化指數高(304不銹鋼角鋼為0.34).奧氏體304不銹鋼角鋼為亞穩定型,在變形時會發生相變,誘發馬氏體相.馬氏體相較脆,因此容易發生開裂.在塑性變形時,隨著變形量的增大,誘發的馬氏體含量也將隨著變形量的增大而增高,殘余應力也越大.殘余應力與馬氏體含量的關系
誘發的馬氏體相含量越高,引起的殘余應力也越大,在加工過程中也就越易開裂.
3、表面劃痕形成的原因
304不銹鋼角鋼拉深件表面出現劃痕主要是由于工件和模具表面存在相對移動,在一定壓力的作用下,致使坯料與模具局部表面直接產生摩擦,加之坯料的變形熱使坯料及金屬屑熔敷在模具表面上,使工件表面擦傷產生劃痕
進出口不銹鋼角鋼的定貨一般以使用中所要求的規格為主,其鋼號為相應的碳結鋼鋼號。也即不銹鋼角鋼除了規格號之外,沒有特定的成分和性能系列。
不銹鋼角鋼的交貨長度分定尺、倍尺兩種,國產不銹鋼角鋼的定尺選擇范圍根據規格號的不同有3—9m、4—12m、4—19m、6—19m四個范圍。日本產不銹鋼角鋼的長度選擇范圍為6—15m。