Rare earth formula salt for deep qpq technology and preparation method thereof

Abstract

The invention discloses a rare earth formula salt for a deep QPQ technology and a preparation method thereof. The rare earth formula salt is prepared from 35-45 parts by weight of CO(NH2)2, 15-25 parts by weight of Na2CO3, 15-25 parts by weight of K2CO3, 3-7 parts by weight of NaCl, 3-7 parts by weight of KCl, 1-5 parts by weight of Na2SO3, 1-5 parts by weight of La2(CO3)3 and 1-5 parts by weight of Ce2(CO3)3. The nitrided salt contains lanthanum carbonate, cerous carbonate and reasonable other components. In a work state, cyanate ions are decomposed to form active nitrogen atoms and the active nitrogen atoms permeate into the surface of an iron base material and form a hard and compact iron nitride on the material surface so that material wear resistance and corrosion resistance are improved. The salt has a low melting point, can keep a certain nitrogen potential at a low temperature, is stable at a high temperature, has a wide melting point temperature range and can form a deep compound layer through nitridation treatment.

Description

technical field [0001] The invention relates to a rare earth formula salt used in deep QPQ technology and a preparation method thereof. Background technique [0002] In the hydraulic transmission with water as the working medium, the hydraulic components are required to have high wear resistance and corrosion resistance at the same time. At present, the commonly used materials for hydraulic components include: corrosion-resistant alloys, engineering plastics, ceramics and their coating materials, etc. Most of these materials have the problems of high price, complicated processing technology or high requirements for working conditions, so it is necessary to find a Inexpensive materials to replace traditional hydraulic transmission element materials. At present, there are many surface modification methods, such as ion nitriding, surface spraying and QPQ salt bath composite treatment technology, etc. These surface modification methods have their own advantages and disadvantage...

AI Technical Summary

Problems solved by technology

However, the current salt bath nitriding treatment technology applied to stainless steel has the following disadvantages: the nitriding base salt is suitable for high temperature, generally between 520-600 ° C, which is not suitable for low temperature treatment; the depth of the nitride layer is not thick enough, resulting in most The application field is relatively limited, and the present invention can provide a kind of liquid nitrogen that expands the melting point temperature range of known nitride salts, and can carry out deep QPQ technology treatment on medium and low carbon steels with a compound layer depth of 70 μm or more. Nitride Salt of Rare Earth Formula