钢材的化学成分是影响淬透性最重要的因素之一。凡是在三角异型钢管钢材中引起“c”曲线右移或左移的合金元素，都对淬适性有着极大的影响。使“c”曲线右移的元素将提高钢的淬透性;使“c”曲线左移的元素将降低钢的淬透性。如45钢与40Cr钢，其含碳量差不多，但，由于前者不含铬元素，后者含铬元素约1%，在同等的热处理条件下，它们的淬透性就显然不同，45钢只能淬远3.5-9.5毫米，而40Cr钢可淬透25-32毫米。
The chemical composition of steel is one of the most important factors affecting hardenability. The alloying elements which cause the "c" curve to move right or left in the triangular shaped steel pipe have a great influence on the quenching suitability. The hardenability of steel will be improved by the elements shifting the "c" curve to the right, while the elements shifting the "c" curve to the left will reduce the hardenability of steel. For example, 45 steel and 40Cr steel have similar carbon content, but because the former does not contain chromium element and the latter contains about 1% chromium element, their hardenability is obviously different under the same heat treatment conditions. 45 steel can harden only 3.5-9.5 mm, while 40Cr steel can harden 25-32 mm. 三角异型钢管形状尺寸、加热温度、冷却方式等，在不同程度上都影响着钢的淬透性。形状尺寸小、加热温度高，连续冷却等都能在一定程度上提高淬透性;而形状尺寸大、加热温度低、等温冷却等却能使淬透性下降。
The shape, size, heating temperature and cooling mode of triangular shaped steel pipe affect the hardenability of steel to varying degrees. Small size, high heating temperature and continuous cooling can improve the hardenability to a certain extent, while large size, low heating temperature and isothermal cooling can reduce the hardenability.
