末端淬火试验是测定钢的淬透性的一种试验方法，淬透性的优劣直接影响钢件的使用性能。某公司开发了一种自动检测钢材淬透性的末端淬火试验装置，并选取45钢、34CrMo4合金钢、40NCD7-03钢及某重大工程用钢使用该装置测试淬透性。结果表明：该自动末端淬火试验装置符合GB/T 225-2006等试验方法的要求。45钢的淬透深度约5 mm，34CrMo4合金钢的淬透深度为7~10 mm，40NCD7-03钢的淬透深度大于50 mm，某重大工程用钢在淬火温度为1 050℃下的淬透性最好。

The end quenching test is a test method to determine the hardenability of steel, and the hardenability directly affects the service performance of steel products. A company has developed a kind of automatic end quenching test device for detection hardenability of steel parts, and the hardenability of 45 steel, 34CrMo4 alloy steel, 40NCD7-03 steel and a major engineering steel were tested by this device. The results show that the automatic end quenching test device meets the requirements of GB/T 225-2006 and other test methods. The quenching depth of 45 steel was about 5 mm, that of 34CrMo4 alloy steel was 7-10 mm, and that of 40NCD7-03 steel was more than 50 mm. The hardenability of a major engineering steel was the best when the quenching temperature was 1 050 ℃.