Iron smelting, nodulizing and inoculating are three of the key processes in the casting of nodular cast iron. The nodulizing and inoculating effect of the molten iron directly impacts the forms of graphite precipitates, eutectic solidification characteristics and cast tissue qualities.
Most foundries adopt the sandwich process for nodulizing: place the nodulizing agent and 60% of the inoculating agent (first inoculating) in the furnace first. After the molten iron is poured into the furnace, another 30% of the inoculating agent is added (second inoculating), and the third inoculating with 10% agent is added during casting. Usually the total inoculating time is within 50 to 80 seconds.
It is critical that real-time control is applied over the key processes such as iron smelting, nodulizing, inoculating, and the quality status of the molten iron, so as to avoid the deteriorating of molten iron as a result of either insufficient or excessive nodulizing and inoculating.
For professional buyers of nodular cast iron products concerned with the quality control of the nodulizing and inoculating process, it is important to check if the temperature of the molten iron at pouring and the particle size and amount of the nodulizing and inoculating agents meet the requirement of the control plan or operation instruction. When appropriate the incoming material inspection records and on-site records should be spot-checked to validate the compliance with the requirement of Advanced Product Quality Planning (APQP).
By Felix SS YUAN
Water Expansion Tank
Primary failure modes:
Viscose; Perforation; Deformation; Bumps; Brittle fracture; Bubbles; Weld marks.
Machine: Short cycle time, Low pressure;
Mould: Low temperature; Insufficient exhaust.
Material: Too much recycled material; Material moisture.
Key quality control of finished products:
1. External dimensions; installation dimensions.
2. Appearance: defects, bumps, marks, accessories.
3. Air tightness test; material testing & approval documents.
4. Packaging: check whether the mark is complete, and whether the protection is reasonable.
By QP LIU
The proposed Automotive Aftermarket QMS Standard, under the development by the Alliance of Automotive Aftermarket Quality Assurance (AAAQA), also includes a series of technical guidance for the implementation of the Standard, for example:
While the conclusion of the ISO9001 and IATF16949 certification process is always a simple “Pass” of “Fail”, AAAQA proposes a composite rating system for grading key elements of a supplier’s QMS in order to assess the effective strength of its quality assurance capability. AAAQA will also set up mechanism to ensure fairness and consistence of both the process and the result of the supplier assessment.
For more detailed information on the aftermarket QMS standard and the general project, please visit www.AAAQA.org.
“China International Auto Parts Expo 2018” (CAPS 2018) will be held at the China International Exhibition Center (CIEC) in Beijing from July 19 to 21, 2018.
Started in 2007, CAPS is part of Beijing International Automotive Manufacturing & Industrial Assembly Expo (BIAME). It is now the largest trade show for automobile spare parts in Northern China. CAPS 2017 attracted more than 1200 exhibitors. More than 51,000 professional visitors from 62 countries and regions also attended the Expo.
The official website of the fair is: http://www.ap-show.com/
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