隨著單片技術的發展，1978年，瑞士人Leeb博士首先提出了一種新的硬度測量方法。 沖擊體在距樣品表面1mm處的沖擊速度和回彈速度，利用電磁原理，感應出與速度成正比的電壓。 里氏硬度值表示為沖擊體的回彈速度與沖擊速度的比值。

  圖片

  計算公式：HL=1000*(VB/VA)

  式中： HL——里氏硬度值

  VB——沖擊體的回彈速度

  VA——沖擊體的沖擊速度

  2.里氏硬度計沖擊裝置

  里氏硬度有七種：D、DC、D=15、C、G、E、DL：

  D：尺寸：f20*70mm，重量：75g。 通用型，用于大多數硬度測量。

  DC：尺寸：f20*86mm，重量：50g。 沖擊裝置很短，主要用于非常狹窄的地方，例如內部孔或圓柱體。

  D 15：尺寸：f20*162mm，重量：80g。 用于測量凹槽或凹槽表面硬度的小頭。

  C：尺寸：f20*141mm，重量：75g。 最小的沖擊能量，用于測量小而輕、薄的零件和堆焊層。

  G：尺寸：f30*254mm，重量：250g。 沖擊能量大，對測量面要求低。 適用于大型、重型和粗糙表面的鍛件。

  E：外形尺寸：f20*162，重量80g 壓頭為人造金剛石，用于硬度極高的材料的測定。

  DL：尺寸：f20*202mm，重量：80g，頭部較小，用于測量窄槽和齒輪表面的硬度。

  3、異形支撐環的使用

  在現場工作中，經常會遇到彎曲的試件，各種曲面對硬度測試結果的影響不同。 在正確操作的情況下，沖擊在試件表面的位置與平面試件的位置相同，所以一般的支撐環為Can。 但是，當曲率小到一定大小時，由于平面狀態變形的彈性狀態存在顯著差異，沖擊體的回彈速度就會降低，從而使里氏硬度顯示值偏低。 因此，對于樣品，建議在測量時使用小支撐環。 對于曲率半徑較小的試樣，推薦使用異形支撐環。

  四、里氏硬度計的測量范圍

  根據里氏原理，只要材料有一定的剛性，能形成回彈，就可以測出準確的里氏硬度值，但很多材料的里氏硬度與其他標準沒有對應的換算關系，所以 里氏硬度計目前只安裝了9種材料的換算表。 具體材料有：鋼及鑄鋼、合金工具鋼、灰口鑄鐵、球墨鑄鐵、鑄鋁合金、銅鋅合金、銅錫合金、純銅、不銹鋼銅。

  對于一些特殊材料的樣品，用戶可以使用本公司提供的擬合曲線作為專用換算表。 在實際生產中，會用到各種金屬材料。 由于里氏硬度計對材料的加工方法和合金元素的組成比較敏感，所以里氏硬度計芯片中存儲的硬度換算表并不能全部滿足用戶的需要。  ，用戶可以在測試過程中使用配件制作自己的專用硬度換算表。

  五、影響里氏硬度計測試精度的因素

  1.數據轉換導致的錯誤

  里氏硬度換算成其他硬度時的誤差包括兩個方面：一方面是里氏硬度本身的測量誤差，它涉及到按方法進行試驗的分散性和國內多臺里氏硬度計的測量誤差。 同類型。 另一方面是不同硬度測試方法測得的硬度比較誤差，這是由于各種硬度測試方法之間沒有明確的物理關系，相互比較時測量不可靠造成的。

  2、特殊材料造成的誤差

  存儲在硬度計中的換算表可能與以下鋼種不同：

  所有奧氏體鋼

  耐熱工具鋼和萊氏體鉻鋼（工具鋼）是導致彈性模量增加的硬質材料，導致L值低。 此類鋼應在橫截面中進行測試

  局部冷卻硬化會導致高L值

  磁鋼會因為磁場的影響而使L值變低。

英斯特力儀器是一家集研發、生產及銷售于一體的 影像測量儀，拉力試驗機, 硬度計 ,探傷儀, 粗糙度儀, 測厚儀, 金相設備廠家, 致力于為客戶提供更好的檢測儀器。

With the development of monolithic technology, in 1978, Swiss Dr. Leeb first proposed a new hardness measurement method. The impact velocity and rebound velocity of the impact body at 1mm away from the sample surface are induced by electromagnetic principle, and the voltage is proportional to the speed. The Richter hardness value is expressed as the ratio of rebound velocity to impact velocity of the impact body.

The picture

Calculation formula: HL=1000*(VB/VA)

Where: HL -- Richter hardness value

VB -- rebound rate of impact body

VA -- impact velocity of the impactor

2. Impact device of Richter hardness tester

There are seven Richter hardness: D, DC, D=15, C, G, E, DL:

D: Size: F20 *70mm, weight: 75g General purpose type for most hardness measurements.

DC: Size: F20 *86mm, weight: 50g. Impact devices are very short and are mainly used in very narrow places, such as internal holes or cylinders.

D 15: Size: F20 *162mm, weight: 80g. A small head used to measure the hardness of a groove or groove surface.

C: Size: F20 *141mm, weight: 75g. Minimum impact energy, used for measuring small and light, thin parts and surfacing layers.

G: Size: F30 *254mm, weight: 250g. Large impact energy, low requirements for measuring surface. Suitable for large, heavy and rough surface forgings.

E: Size: F20 *162, weight: 80g Indenter is artificial diamond, used for the determination of high hardness materials.

DL: size: F20 *202mm, weight: 80g, small head, used to measure the hardness of narrow groove and gear surface.

3, the use of special-shaped support ring

In field work, bending specimens are often encountered, and various curved surfaces have different effects on hardness test results. Under the condition of correct operation, the position of the impact on the specimen surface is the same as that of the plane specimen, so the general support ring is Can. However, when the curvature is small to a certain size, due to the significant difference in the elastic state of the plane state deformation, the rebound velocity of the impact body will be reduced, resulting in a low value of The Richter hardness. Therefore, for samples, it is recommended to use small support rings when measuring. For samples with small radius of curvature, it is recommended to use special-shaped support rings.

Four, the measuring range of the Richter hardness tester

According to the Richter principle, accurate Richter hardness value can be measured as long as the material has a certain rigidity and can form a rebound. However, there is no corresponding conversion relationship between the Richter hardness of many materials and other standards, so the Richter hardness tester only has 9 materials conversion table installed at present. Specific materials are: steel and cast steel, alloy tool steel, gray cast iron, nodular cast iron, cast aluminum alloy, copper zinc alloy, copper tin alloy, pure copper, stainless steel copper.

For some special material samples, users can use the fitting curve provided by our company as a special conversion table. In actual production, all kinds of metal materials will be used. Because the Hardness tester is sensitive to the processing method of materials and the composition of alloy elements, the hardness conversion table stored in the Hardness tester chip can not meet the needs of users. , users can use accessories to make their own special hardness conversion table during the test process.

5. Factors affecting the testing accuracy of The Richter hardness tester

1. Errors caused by data conversion

The error of converting The Richter hardness into other hardness includes two aspects: on the one hand, the measuring error of the Richter hardness itself, which involves the dispersion of the test by method and the measuring error of many Domestic Richter hardness testers. The same type. On the other hand, the hardness comparison error measured by different hardness testing methods is caused by the unreliability of measurement due to the lack of clear physical relationship between various hardness testing methods.

2. Errors caused by special materials

Conversion tables stored in the durometer may differ from the following steel grades:

All austenitic steels

Heat resistant tool steels and lestenitic chromium steels (tool steels) are hard materials that result in increased elastic modulus, resulting in low L values. This type of steel shall be tested in cross section

Local cooling hardening results in high L values

The L value of magnetic steel will be lower because of the influence of magnetic field.