培林-軸承零件熱處理有哪些不足

從軸承零件粗糙口上可觀察到淬火後培林的顯微組織過熱。

組合滾針軸承是由一個向心滾針軸承和一個推力軸承組合而成，因此能夠承受徑向和軸向負荷。組合滾針軸承在徑向空間受到限制時，能爲軸承配置定位。它們特別適合于其它類型的定位軸承占據太多空間或軸向負荷很大、轉速很高或對僅僅推力墊圈潤滑不足的應用場合。

但要確切判斷其過熱的程度必須觀察顯微組織。若在GCr15鋼的淬火組織中出現粗針狀馬氏體，則爲淬火過熱組織。形成原因可能是淬火加熱溫度過高或加熱保溫時間太長造成的全面過熱；也可能是因原始組織帶狀碳化物嚴重，在兩帶之間的低碳區形成局部馬氏體針狀粗大，造成的局部過熱。過熱組織中殘留奧氏體增多，尺寸穩定性下降。由于淬火組織過熱，鋼的晶體粗大，會導致零件的韌性下降，抗沖擊性能降低，軸承的壽命也降低。過熱嚴重甚至會造成淬火裂紋。

沖壓軸承與鑄件、鍛件相比，具有薄、勻、輕、強的特點。沖壓可制出其他方法難于制造的帶有加強筋、肋、起伏或翻邊的工件，以提高其剛性。由于采用精密模具，工件精度可達微米級，且重複精度高、規格一致，可以沖壓出孔窩、凸台等。

沖壓軸承一般不再經切削加工，或僅需要少量的切削加工。熱沖壓件精度和表面狀態低于冷沖壓件，但仍優于鑄件、鍛件，切削加工量少。

欠熱

淬火溫度偏低或冷卻不良則會在顯微組織中産生超過標准規定的托氏體組織，稱爲欠熱組織，它使硬度下降，耐磨性急劇降低，影響軸承壽命。

淬火裂紋

軸承零件在淬火冷卻過程中因內應力所形成的裂紋稱淬火裂紋。造成這種裂紋的陶瓷軸承原因有：由于淬火加熱溫度過高或冷卻太急，熱應力和金屬質量體積變化時的組織應力大于鋼材的抗斷裂強度；工作表面的原有缺陷（如表面微細裂紋或劃痕）或是鋼材內部缺陷（如夾渣、嚴重的非金屬夾雜物、白點、縮孔殘余等）在淬火時形成應力集中；嚴重的表面脫碳和碳化物偏析；零件淬火後回火不足或未及時回火；前面工序造成的冷沖應力過大、鍛造折疊、深的車削刀痕、油溝尖銳棱角等。總之，造成淬火裂紋的原因可能是上述因素的一種或多種，內應力的存在是形成淬火裂紋的主要原因。淬火裂紋深而細長，斷口平直，破斷面無氧化色。它在軸承套圈上往往是縱向的平直裂紋或環形開裂；在軸承鋼球上的形狀有S形、T形或環型。淬火裂紋的組織特征是裂紋兩側無脫碳現象，明顯區別與鍛造裂紋和材料裂紋。

熱處理變形

軸承零件在熱處理時，存在有熱應力和組織應力，這種內應力能相互疊加或部分抵消，是複雜多變的，因爲它能隨著加熱溫度、加熱速度、冷卻方式、冷卻速度、零件形狀和大小的變化而變化，所以熱處理變形是難免的。認識和掌握它的變化規律可以使軸承零件的變形（如套圈的橢圓、尺寸漲大等）置于可控的範圍，有利于生産的進行。當然在熱處理過程中的機械碰撞也會使零件産生變形，但這種變形是可以用改進操作加以減少和避免的。

表面脫碳

軸承零件塑膠軸承在熱處理過程中，如果是在氧化性介質中加熱，表面會發生氧化作用使零件表面碳的質量分數減少，造成表面脫碳。表面脫碳層的深度超過最後加工的留量就會使零件報廢。表面脫碳層深度的測定在金相檢驗中可用金相法和顯微硬度法。以表面層顯微硬度分布曲線測量法爲准，可做仲裁判據。

軟點

由于加熱不足，冷卻不良，淬火操作不當等原因造成的軸承零件表面局部硬度不夠的現象稱爲淬火軟點。它象表面脫碳一樣可以造成表面耐磨性和疲勞強度的嚴重下降。

焊接護具-電焊機選購常識

電焊機的用途很廣泛。不管電離子焊接機是大的造船企業、工礦企業和各種建築企業電焊機是不可缺少的工具。電焊機是用于材料焊接的，在使用時是帶電的，尤其是一些小的施工單位爲節省成本購買便宜的電焊機，在施工現場惡劣的環境下使用很容易引起觸電、著火、脫焊的現象發生，會危及人身安全氬焊機和財産安全。因爲焊接質量不好也會造成“豆腐CO2焊機渣”工程。所以在選購電焊機時要注意的幾點要求：

　　一、在選購電焊機産品時，要到正規的生産企業或大商場去選購，並且要選購市場占有率較高的品牌名優産品。千萬不要貪圖便宜到小商店去購買，那裏焊接護具的電焊機質量無法達到保證。

　　二、選購時，檢查産品上半自動電焊機的銘牌是否有生産廠家的名稱、生産地址、規格型號、焊接電流調節範圍、負載持續率及輸入電壓電流等一些內容，隨後根據工作需要來確引擎電焊機定自己要購買的電焊機。

　　三、購買時可以要求經銷商提供産品質量檢驗報告或合格證。因電焊機産品是國家強制性認證産品，所以購買時TIG焊機一定要確認該産品是否通過“3C”認證。

　　四、購買時一定要檢查該産品是否有接地螺釘，接地螺釘連接處應無油漆接地良點焊機好。機芯是否清潔絕緣是否有損壞，以保證使用安全，必要時也可檢測一下。

　　五、購買前可以通電檢查一下面板上的開關的操作，轉換以及安裝情況，電源指示燈的亮滅，風扇是否正常，電源部分是否有異常的振動及蜂鳴聲，是否有異味，外觀上是否有變色等發熱現象，以保證電焊機的質量，充分發揮電焊機的性能。

　　六、如要購買氣體保護焊機的，在購買前還要檢查配件是否齊全，送絲機是否有油汙，轉動是否平穩，連接電纜是否匹配外表絕緣是否有損壞，以保證電弧的穩定性。

分泌物變多-性感女人必備 私密處保養妳應該知道的七件事

女人都愛保養，尤其隨著年紀日漸增分泌物變多長，無論是臉上還是身體的保養都砸下重本，但有個地方你可能常忽略，那就是女人最特別擁有的私密處！性愛生活調查報告，有27%的台灣女性表示，在性行為中最在意自己私處的味道，相信大家都很愛自己的身體，偶爾身體狀況不太好，而有些異味，讓性愛進行或甚至走在路上時有點小尷尬，其實女人都該擁有健康私密處，而這些小知識你應該知道。

一、用清水清潔最乾淨

隨著私密處清潔產品引進台灣，大家終於開始稍微重視私密部位的保養，但其實清水，就能達到最好的清潔效果，如果使用太多肥皂或沐浴乳反而會破壞正常PH值（正常應該是3。8~4。6的弱酸性），使細菌滋生的機率增加，如果你不用沐浴乳不安心，記得確保沒有任何清潔劑殘留。也要慎選私密處清潔液，我們都想要有好聞的味道，但過多香精添加容易傷害分泌物有異味皮膚。

二、用最溫柔的觸感對待它

路邊攤不到一百元的內褲固然可愛，但一分錢一分貨，純棉質感才能夠呵護妳最細嫩的皮膚，除了內褲外，最常接觸的就是每個月都用得到的衛生棉，無論是棉條還是護墊，都建議使用三小時就要換新，畢竟細菌我們看不到，勤更換也不容易有異味，醫生也建議，非必要不要使用護墊，

三、做愛後上個廁所最乾淨

一般人可能都知道做愛前該洗乾淨，做愛過後也該沖澡才能有效清潔，但在清潔前，強烈建議，你得先小便，因為在歡愛時，細菌可能會進入尿道，而小便可以有效讓這些細菌能夠離開體內，也免得到尿道或是膀胱炎。除了細菌外，若是精液殘留會造成酸鹼不平衡，容易使細菌孳生，如果你不愛用保險套，那就完事後加強清潔吧！

四、過緊的褲子會讓陰道有壓力

貼身內搭或牛仔褲有型又好看，但太過緊貼肌膚會讓私密處無法呼吸，空氣無法流通外，皮膚也會非常缺水，進而容易散發異味。穿上較為寬鬆的褲子讓美腿透透氣吧！如果因為淋雨或是沾染的經血而弄濕，最好儘快更換褲子，去除水氣，讓細菌沒有溫床可以增生。

五、定期除毛，讓陰毛呼吸

許多的朋友從來沒有修剪過陰毛，對他們來說，自己拿剃刀修剪是非常害羞的事情，但親愛的女人，就和頭髮一樣，陰毛也需要藉由修剪來汰舊換新，才能不藏汙納垢和引發異味，妳可以沿著比基尼線修剪，但不需要全部剃光，讓它呈現舒服又能保護的最佳狀態。

六、吃大蒜和水果，妹妹味道自然香

快丟掉那些香精沐浴乳或是香氣潔膚巾，讓陰道味道好聞，靠水果就能做到！多吃小紅莓、鳳梨、草莓這類的水果，不只讓妳的陰道能有自然的氣味，也能夠幫助代謝身體毒素，一舉兩得。另一個有益食物就是大蒜，大蒜也許會帶來口臭但卻能給你一個氣味芬芳的健康陰道，它能有效殺死酵母，進一步達到預防酵母菌感染的作用，讓私密處保養私密處更健康。

七、陰道也要每天做運動

每週做運動能夠幫助女人維持完美體態，其實陰道也需要常常做運動！之前紅教過的凱格爾運動就能派上用場，不只能讓陰道更健康，也能提升性生活的品質，建議女人每天做，並且逐漸增加次數和長度。如果不知道做得對不對，很推薦利用小工具輔助，像是每天練習陰道啞鈴，久了你會感受到不可思議的成效。

奇亞籽減肥-瘦身 方法有哪些 兩大減肥誤區大曝光

有效的減肥，不僅要能瘦，還得保得排便順暢住減肥成果，還得健康，不會對身體造成損傷，才是減肥的意義所在。快速有效地瘦身方法有哪些呢？下面給你一一介紹。

一、飲食減肥食譜

1、清蒸羊肉
羊肉是冬季進補的最佳食物。羊肉性溫熱，補氣滋陰。羊肉可以暖身，同時羊肉含有一種類似“燃脂素”的營養成分，它是轉運脂肪酸進入線粒體的載體。而脂肪酸必須在線粒體內才可以燃燒。因此多吃羊肉有助于燃燒脂肪。

清蒸羊肉的做法：

1、瘦羊肉750克切成3大塊，洗幹淨後減肥餐放入沸水鍋裏煮一下，然後撈出洗幹淨減肥瘦身。
2、羊肉再次放入沸水中，加入蔥、姜、大茴香、花椒，煮熟。
3、將羊肉撈出，放涼，去除浮沫，切成薄片，然後點入碗底在上面放入少量蔥、姜，加入雞湯上籠蒸15分奇亞籽減肥鍾。
4、去除蔥、姜、湯瀝入鍋裏，肉扣入湯盤，再將纖維減重原湯加適量精鹽和味精調勻，加入麻油即可食用。

2、苦瓜炒蛋
苦瓜具有減肥的作用。涼瓜含有清脂素，當進入減肥代餐人體後，清脂素會作用在小腸上。通過改變腸細胞網孔，阻止脂肪、多糖等高熱量大分子物質的吸收。從而加速體內小去水腫分子營養的吸收，但又不參與人體代謝。

苦瓜炒蛋的做法：

1、將苦瓜切成薄片，用鹽揉抓片刻，然後用手擠掉苦瓜水。
2、鍋裏加清除宿便入是少量的油，倒入一點點料酒贊一下。然後倒入苦瓜炒一下，加入一點糖，炒到八成熟的時候裝碟。
3、雞蛋打成雞蛋液，鍋裏加入油，略炒雞蛋。然後加入苦瓜，和雞蛋一起翻炒幾下即可。

Rubber O-Ring-Vivitar Digital Cameras

There is a huge Rubber Gasketvariety of digital cameras to choose fromRubber Parts。 Vivitar is one of the more respected and well-known names。 The Vivitar digital camera range of sporty and versatile cameras suit a wide range of people。 There are seventeen models in the Vivitar range: three DVR models， which have the functionality of both MP3 players and DVRs。

Vivitar made a big splash when the brand was first introduced to the celebrity mainstream。 Vivitar´s line of cameras were used by some of the entertainers at the MTV Music Awards and the Sundance FilmCustom Mold Rubber Parts Festival。 Although this has helped， they are not the only things that have stood Vivitar in such high stead。 The range of affordable and good looking cameras make them a good choice for anyone looking for a new digital camera。

Underwater Fantasy

Although for most consumers， the idea of having a waterproof camera might seem a little over the top and would at the most bring up images of being protected from a heavy downpour， rather than fully-submerged。 The ViviCam 6200w features a rubber seal and helpsRubber Seal to keep it waterproof at up to 30 feet below water， making it ideal for outdoor activities， and for heavy showers。

A two inch monitor gives plenty of space to view the up to 6。0 megapixel images， rather than through the viewfinder。 There is also a built-in flash， support for more memory by buying another memory card with higher capacity。 There is also a range of picture editing software to allow standard pictures to be given that little extra something and to do standard edits like removing red-eye。

Vivitar DVR-530

The are three cameras in the DVR range， but the DVR-530 offers a little something extra。 The standard stills camera options are all there， but included are the ability to take movies， and to listen to MP3s。 The 2。5 inch screen allows viewing of pictures that can have up to a 5。0 megapixel resolution。 For close-ups there is a standard 3x optical / 4x digital zoom。 The video recording capabilities don´t match those of traditional video cameras， but that shouldn´t bother most people。 With a large amount of video only be distributed and viewed online， there is often very little reason to have the super high quality when the final version is viewed on a computer screen。

Wide Range

The functional range of Vivitar cameras extends from 5。0 megapixels up to 10 megapixels。 The range follows budgetary considerations， and the top-end models will set you back a bundle。 The ability to change many of the features is one of the greatest assets of the upper range models。 These features are indispensable for the professional photographer。 Have a look at the whole rangeRubber O-Ring and you´ll be sure to find something suitable。

All in one computer-How Long Will My Flat Panel Tv Live?

A decent amount All in one computerof people worldwide have taken up possession of flat panel televisions。 One would almost think it was a newborn baby in these people´s possession with the care and attention these televisions receive over time。 Perhaps that´s because a plasma or LCD television can， indeed， set one back a few thousand dollars。

Other thanVideo wall the intense difference in your home theater quality， in some circles， one of these TV gems represents a kind of status symbol。 With that kind of financial investment this would warrant a special kind of maintenance and care。 Like with anything you take care of， it should give you a quality performance for years to come。 So， let´s take aBox PC look at the length of time one receives such performance from their flat panel TV。 In order to do this， we will be dissecting each type of high performance television。

Flat Panel Televisions:

Originally the word "lifespan" was used to prose this topic but that was wrong in a sense。 A television is measured as a "Half-Life"， the time before the television´s screen dims from one half of the original brightness。 Every television from Flat panels to CRTs loose brightness over time and this cannot be helped。

Should you， aspanel PC a prospective buyer or owner， worry about the lifespan of your television? Not really， but some people do commonly fear their extravagant televisions will burn out long before the classic yet reliable picture tube sets of yesteryear。

Consumer Reports， an independent nonprofit organization， published a report last year， which explains flat panel sets are just as reliable as CRT TVs in their first year。 Most won´t be fearful about long-term reliability because they would more than likely be looking for a new TV long before their flat panel fades to black。

The LCD Screen:

The winner in the debate between longevity of LCD and plasma televisions is the LCD。 The LCD panel alone holds a virtually limitless lifespan because of this the screen´s LCD light source。

The light bulb of a the LCD is what produces pictures， and just as with any other light bulb， the light will dim over a period of time after repeated use。 Hence both the bulb andsunlight readable the LCD screen life are equivalent to one another， the proposed life span ranges from 30，000 to 60，000 hours。 Some manufacturers estimate a larger sum of 80，000 hours。 Replacing these bulbs will easily increase your television´s lifespan。 Watching an average of about six hours a day will givedigital signage you just about 28 years before the LCD´s brightness begins to dim to half it´s original level。

The PlasmaFanless pc Television:

Plasma is somewhat inferior to it´s LCD counterpart in the case of a lifespan。 The common mistake is that a plasma television will last almost 10 years， this as stated already， is not true。

Plasma televisions use gases where the LCD uses bulbs for lighting。 Like anything else， plasma gases will decay overtime。 This process is a slow and gradual one with ranges from 20，000 to 30，000 hours along with the manufacturer estimation of 60touch screen monitor。000。 All of theseIP66 estimates are figured under optimal conditions。 Currently there is no form of replacement for plasma gases。 This makes the average six hour a day of televisionIndustrial pc equate to 14 years before the plasma´s brightness begins to fade to one half of the original level of brightness。

To put these life spans in terms of relative experience - the cathode ray tube or CRT televisions， which we have been most accustomed to， have one of the longest life spans of up toIndustrial monitor more than 80，000 hours。

sintered metal-Metal Stamping House

Stampings is thepowder metal process of cutting and forming metal alloys into specific forms especially for use as components for large machinery or structures。 Metal sheets can be molded into different pre-defined forms for use as food as regular pots and jars。 The most common alloys used in metal stamping steel zinc nickel aluminum and titanium。 Stampings is a very effective and productive means of production of many types of metal on a large scale。

In stamping metalpowder metal sheets are placed in a matrix or a press tool which is specially designed cavity that gives the preferred form of sheet metal。 Upper part of the matrix is connected to the press slide while the lower component connects to the press bed。 Specific component known as the blow pushes the sheet metal through the die thus performing the actual development of the operation。 After pressing metal coated with gold palladium nickel or tin to prevent corrosion。

Coverage also increases wear and solderable nature of the product。 Sometimes leaves are also pre-coated before the stamping process and then purify the product from excess stamping oils and films。 The product is then heat-treated to make it stronger because it is still in soft condition after stamping。 The product is then subjected to the process of deburring to remove sharp corners。 This is done with chemicals or abrasives。 Stampings also includes other processes such as metal-piercing cleaning shaping and drawing on the same machines。

Precision metal stamping is applicable to many industries like computers electronics electrical dental aerospace instrumentation military specs defense telecom and automotives。 There are many methods in precision metal stamping for producing stamped prototypes。 Blank creation is one such method。 Blank creation involves the creation of a flat state of the component。 The flat blank sheet is then used to make the parts features。 In blank creation there are many processes like nibbling chemical etching water jet cutting wire EDM punch and die。

Stamping presses have specific strength speed and accuracy to give a definite form to the metal。 There are two types of metal stamping presses: mechanical and hydraulic。 They are available in a wide range of power size stroke length and operating speed。

Stampings are gradually replacing other metal forming processes like casting forging fabrication and processing。 One reason for this is the very low cost of metal stamping。 Dies forsintered metal stamping cost less than those used in the forging and casting。 In addition the metals used in metal stamping can be harder than those used in other processes resulting in a final product stronger。 The cost of secondary processes like cleaning and plating is also significantly reduced。

In addition there are certain foods that should be done only through a metal stamping: Base weights brackets balance clamps brake flanges conveyer flights bushing seats engine bases flywheel shrouds and friction plates。 There are also various types of stamping including: Deep drawn stamping electronic stamping embossing Fourslide medical stamping embossing and short-term progressive stamping。 The most commonly used type is a progressive drawingsintered metal Die where the sheet metal passes through a series of stamps and stamping dies made all at once thereby significantly reducing the time it takes。