{"id":23433,"date":"2025-03-29T11:43:09","date_gmt":"2025-03-29T03:43:09","guid":{"rendered":"https:\/\/www.meetyoucarbide.com\/?p=23433"},"modified":"2025-03-29T11:45:24","modified_gmt":"2025-03-29T03:45:24","slug":"roll-ring-fractures","status":"publish","type":"post","link":"https:\/\/www.meetyoucarbide.com\/ar\/roll-ring-fractures\/","title":{"rendered":"Practical Investigation and Solutions for Roll Ring Fractures in High-Speed Wire Rod Production"},"content":{"rendered":"
Tungsten carbide roll rings (WC rolls) are high-performance rolling mill components made from tungsten carbide (WC) particles bonded with cobalt (Co) or nickel (Ni) through powder metallurgy. They are widely used in high-speed wire rod mills, bar mills, and section mills due to their exceptional wear resistance, thermal stability, and strength.<\/p>\n

They can be usefully used for finishing stands of high-speed wire rod mills (up to 120 m\/s),precision \u0627\u0644\u0645\u062a\u062f\u0627\u0648\u0644<\/a> of rebars, alloy steels, and non-ferrous metals, and high-reduction passes where wear resistance is critical<\/p>\n

Practical condition<\/h1>\n

Located in Guangdong Province, A metal production company commissioned its high-speed wire rod mill (with an annual capacity of 1.2 million tons of \u03c65.5~\u03c616mm wire rods) in December 2010 to enhance production efficiency and meet market demands.<\/p>\n

The mill primarily consists of five key components: roughing mill, intermediate mill, pre-finishing mill, and finishing mill. The roughing mill features a single-line configuration with 5 stands (\u03c6550\u00d75) arranged in horizontal-horizontal-vertical-horizontal-vertical (HHVHV) pattern. The intermediate mill comprises 8 stands (\u03c6550\u00d72+\u03c6450\u00d74+\u03c6350\u00d72) with all-horizontal rolls. The pre-finishing mill has 8 stands (dual-line, 4 stands per line) configured as cantilever-type two-high mills (\u03c6285\u00d74\u00d72) with alternating horizontal\/vertical arrangement. The finishing mill contains 20 stands (dual-line, 10 stands per line) of cantilever-type two-high mills (gang-driven, \u03c6228\u00d75+\u03c6170\u00d75) in 45\u00b0 top-cross configuration.<\/p>\n

Due to humid climatic conditions, the mill encountered roll ring explosions caused by moisture-induced rusting of roll rings and taper sleeves. A technical task force was established to identify root causes and implement corrective measures to ensure stable production.<\/p>\n

\"\"<\/p>\n

Production Process Overview<\/h1>\n

The manufacturing process flows as follows:<\/p>\n

1.After single-pass rolling in the roughing mill, the billet undergoes head\/tail cropping at #1 flying shear (with emergency scrap chopping capability), then diverges into dual lines via a distributor for intermediate rolling under micro-tension control.<\/p>\n

2.Following intermediate \u0627\u0644\u0645\u062a\u062f\u0627\u0648\u0644<\/a>, the stock passes through #2 flying shear for cropping before entering pre-finishing mill, where pneumatic vertical loopers enable twist-free, tensionless rolling for precise dimensional control.<\/p>\n

3.Pre-finished stock undergoes water cooling and #3 flying shear cropping before entering finishing mill. Emergency shutoff shears activate to prevent further stock entry during malfunctions.<\/p>\n

4.The 45\u00b0 top-cross finishing mill employs gang-driven tungsten carbide roll rings for twist-free micro-tension rolling, achieving final dimensions at speeds up to 95m\/s for \u03c65.5\uff5e7mm products.<\/p>\n

\"carbide<\/p>\n

Root Cause Analysis of Roll Ring Failures<\/h1>\n

The cost-optimized tungsten carbide roll rings exhibited these failure mechanisms:<\/p>\n

Ambient humidity caused rust corrosion at roll ring\/taper sleeve interfaces<\/p>\n

Thermal fatigue from cyclic temperature variations (Fig.1) accelerated crack propagation<\/p>\n

Insufficient cooling exacerbated thermal stresses (increased \u0394T)<\/p>\n

Improper assembly caused taper sleeve seizure<\/p>\n

Brittle material properties increased handling damage risks<\/p>\n

 <\/p>\n

Technical Improvements & Process Controls<\/h1>\n

Material Selection Optimization<\/h2>\n

The YGR-series roll rings were selected for their Ni\/Cr-enhanced properties:<\/p>\n

1.Superior oxidation resistance (700-1000\u2103)<\/p>\n

2.Improved acid corrosion resistance (pH\u22647.2)<\/p>\n

3.Enhanced thermal crack resistance<\/p>\n

4.Optimal hardness-toughness balance across mill stands<\/p>\n

 <\/p>\n

Cooling System Enhancements<\/h2>\n

Implemented strict water management protocols:<\/p>\n

1.Flow rates: 18-25m\u00b3\/h per stand (slot-width dependent)<\/p>\n

2.Pressure maintenance: 3-7bar at nozzles<\/p>\n

3.Monthly water quality testing for particulate control<\/p>\n

Dedicated pipe alignment inspections during maintenance<\/p>\n

 <\/p>\n

Optimum Rolling Tonnage<\/h2>\n

Established safe grinding thresholds at 0.2-0.4mm crack depth:<\/p>\n

Stands 1-4: 1,800-2,500 tons<\/p>\n

Stands 5-8: 1,500-2,000 tons<\/p>\n

Stands 9-10: 600-1,000 tons<\/p>\n

 <\/p>\n

Precision Assembly Standards<\/h2>\n

Mandatory surface cleaning before assembly<\/p>\n

Prohibited impact mounting methods<\/p>\n

Individual roll storage in partitioned containers<\/p>\n

Strict taper sleeve inspection\/rejection criteria<\/p>\n

 <\/p>\n

\u0627\u0633\u062a\u0646\u062a\u0627\u062c<\/h1>\n

The comprehensive improvement program addressing material selection, cooling optimization, production control, and precision maintenance successfully resolved roll ring failures, achieving sustained operational stability. This methodology provides valuable reference for similar applications.<\/p>\n

Key Recommendations<\/h2>\n

1.Select roll ring grades considering environmental factors<\/p>\n

2.Maintain rigorous cooling water quality standards<\/p>\n

3.Adhere to prescribed rolling tonnage limits<\/p>\n

4.Implement precision handling and maintenance protocols<\/p><\/div>\n

<\/p>","protected":false},"excerpt":{"rendered":"

Tungsten carbide roll rings (WC rolls) are high-performance rolling mill components made from tungsten carbide (WC) particles bonded with cobalt (Co) or nickel (Ni) through powder metallurgy. They are widely used in high-speed wire rod mills, bar mills, and section mills due to their exceptional wear resistance, thermal stability, and strength. They can be usefully…<\/p>","protected":false},"author":2,"featured_media":23436,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[107],"tags":[],"class_list":["post-23433","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-industrial-products-weekly"],"jetpack_featured_media_url":"https:\/\/www.meetyoucarbide.com\/wp-content\/uploads\/2025\/03\/2.webp","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.meetyoucarbide.com\/ar\/wp-json\/wp\/v2\/posts\/23433","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.meetyoucarbide.com\/ar\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.meetyoucarbide.com\/ar\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/ar\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/ar\/wp-json\/wp\/v2\/comments?post=23433"}],"version-history":[{"count":3,"href":"https:\/\/www.meetyoucarbide.com\/ar\/wp-json\/wp\/v2\/posts\/23433\/revisions"}],"predecessor-version":[{"id":23439,"href":"https:\/\/www.meetyoucarbide.com\/ar\/wp-json\/wp\/v2\/posts\/23433\/revisions\/23439"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/ar\/wp-json\/wp\/v2\/media\/23436"}],"wp:attachment":[{"href":"https:\/\/www.meetyoucarbide.com\/ar\/wp-json\/wp\/v2\/media?parent=23433"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/ar\/wp-json\/wp\/v2\/categories?post=23433"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/ar\/wp-json\/wp\/v2\/tags?post=23433"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}