{'fraction_non_alphanumeric': 0.03140096618357488, 'fraction_numerical': 0.02254428341384863, 'mean_word_length': 5.4404145077720205, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Refractory/steel/inclusion interactions in Al-deoxidised valve spring steel treated with Na2CO3

ABSTRACT Ca treatment is generally used in the production of Al-deoxidised steel to prevent nozzle blockage by modifying high melting point inclusions such as MgO·Al2O3 (Melting point: 2408 K). However, the successful application of Ca treatment can be quite difficult due to the requirements for stringent control of the amount of calcium that is added. In the present paper, a novel and effective method of inclusion modification by Na2CO3 treatment is developed and the evolution process of inclusions in Al-deoxidised steel with Na2CO3 treated is studied, which is in good agreement with FactSage calculation results. In addition, the relevant refractory/steel/inclusion interaction mechanisms are also discussed. The experimental results show that MgO–Al2O3 inclusions can be transformed into Na2O–MgO–Al2O3–SiO2 inclusions with low-melting points by Na2CO3 treatment. After Na2CO3 addition, both the dissolved [Na] and [Si] start to reduce MgO and Al2O3 in the generated MgO–Al2O3 inclusions from outside to inside, accompanied with the reduction of MgO–Al2O3 reaction layer at the steel-refractory interface by [Na] and [Si] in the steel.