97色老99久久九九爱精品|中午字幕不卡一区二区三区|亚洲色婷婷久久99精品|国产精品岛国久久久久

Hotline:+86-512-65952986
  • Difficulties in hardness testing of metal stamping parts

In order to obtain high surface hardness and wear resistance, many molds and stamping die accessories need surface heat treatment, such as surface nitriding. For such a mold, people are very concerned about its surface hardness and depth of hardened layer. When testing the hardness of die steel of stamping parts after surface heat treatment, there is a wrong practice that is worth correcting. This is the improper use of the Leeb hardness tester on this occasion. This is determined by the principle of the Leeb hardness tester. The three commonly used hardness testers, Bu, Luo and Wei, all adopt the static testing principle, which is to slowly press a hard indenter into the surface of the sample, and then test the depth or size of the indentation to determine the hardness value. The Leeb hardness tester adopts the dynamic testing principle.


It is to determine the hardness value of the sample by impacting the surface of the sample with a ball of specified mass at the specified speed and testing the difference between its initial speed and the speed after rebound. To understand this, just look at how thick the standard hardness block of the Leeb hardness tester is. It is obvious that the hardness value measured by it is not the hardness of the nitriding layer or the hardness of the base material, but the result of the joint action of the two. Because the thickness of the surface layer of the stamping part is different, different results will inevitably be obtained.

Home
Tel
Contact
安阳市| 闸北区| 南郑县| 嘉义市| 伊宁县| 吐鲁番市| 包头市| 荣成市| 嵊泗县| 北安市| 平遥县| 江永县| 望谟县| 平远县| 威海市| 德令哈市| 新邵县| 信宜市| 昌吉市| 周口市| 汕头市| 通州市| 康保县| 清徐县| 宁远县| 桐庐县| 金山区| 张家川| 克东县| 化德县| 当涂县| 清水河县| 陆河县| 潞西市| 镇赉县| 东方市| 兴海县| 博客| 神木县| 唐山市| 卓资县|