Erosion problem in tool steel using cold box core-making process

摘要

This paper presents the erosion results of the AISI H13 steel impinged by resin-bonded silica sand, using a testing rig that closely simulates the real blowing conditions during industrial core-making. Steel specimens were heat treated to obtain hardness of 294, 445 and 595 HV200 (29, 45 and 55 HRC). Erosion tests were carried out at impingement angles from 20° to 90° and air drag pressures of 1.38, 2.07 and 2.76 bar (20, 30 and 40 psi). The main results are summarized as follows: (ⅰ) The harder material, the lower erosion; (ⅱ) the maximum erosion rate is at 30°; (ⅲ) Little difference in erosion rate at impact angle of 60° and 90° for a constant pressure tested regardless of the hardness level; (ⅳ) As the pressure increases, so does the erosion rate, being more sensitive for low impact angles. Finally, a differential form of the general erosion equation is applied on a practical core-making case to evaluate the erosion rate of the H13 steel at 30° and 90° impingement angles.