{"id":5711,"date":"2025-12-24T01:49:43","date_gmt":"2025-12-24T01:49:43","guid":{"rendered":"https:\/\/korea-transmission.com\/?p=5711"},"modified":"2025-12-24T01:50:38","modified_gmt":"2025-12-24T01:50:38","slug":"gb-t-3098-7-2000-self-tapping-screw-fastener-properties","status":"publish","type":"post","link":"https:\/\/korea-transmission.com\/pt\/blog\/gb-t-3098-7-2000-self-tapping-screw-fastener-properties\/","title":{"rendered":"GB\/T 3098.7-2000: Propriedades dos parafusos autoatarraxantes"},"content":{"rendered":"<div style=\"margin-bottom: 30px;\">\n<h2 style=\"color: #333; font-size: 1.5em; border-bottom: 2px solid #ddd; padding-bottom: 10px;\">Sum\u00e1rio do artigo<\/h2>\n<p style=\"margin-bottom: 15px;\">Este artigo fornece uma vis\u00e3o geral estruturada da norma GB\/T 3098.7-2000, otimizada para clareza e aplica\u00e7\u00e3o pr\u00e1tica em engenharia mec\u00e2nica. O resumo garante uma cobertura abrangente dos principais aspectos:<\/p>\n<ul style=\"list-style-type: disc; padding-left: 20px; margin-bottom: 20px;\">\n<li>Introdu\u00e7\u00e3o: \u00c2mbito e import\u00e2ncia da norma.<\/li>\n<li>Materiais: Composi\u00e7\u00e3o qu\u00edmica e diretrizes de fabrica\u00e7\u00e3o.<\/li>\n<li>Propriedades mec\u00e2nicas e de desempenho: Requisitos detalhados, incluindo dureza, torque e muito mais.<\/li>\n<li>M\u00e9todos de teste: Procedimentos para verifica\u00e7\u00e3o de conformidade.<\/li>\n<li>Chaves de torque: Especifica\u00e7\u00f5es para equipamentos de teste.<\/li>\n<li>Marca\u00e7\u00e3o: Requisitos de identifica\u00e7\u00e3o e rotulagem.<\/li>\n<li>Perguntas frequentes: d\u00favidas comuns e informa\u00e7\u00f5es de especialistas.<\/li>\n<\/ul>\n<\/div>\n<div style=\"margin-bottom: 30px;\">\n<h2 style=\"color: #333; font-size: 1.5em; border-bottom: 2px solid #ddd; padding-bottom: 10px;\">Introdu\u00e7\u00e3o \u00e0 norma GB\/T 3098.7-2000<\/h2>\n<p style=\"margin-bottom: 15px;\">A norma GB\/T 3098.7-2000 especifica as propriedades mec\u00e2nicas de parafusos autoatarraxantes utilizados em fixadores. Ela se aplica a parafusos fabricados em a\u00e7o cementado, garantindo confiabilidade em aplica\u00e7\u00f5es que exigem alto desempenho sob tens\u00e3o mec\u00e2nica. Essa norma \u00e9 essencial para ind\u00fastrias como a automotiva, a da constru\u00e7\u00e3o civil e a de m\u00e1quinas, onde os parafusos autoatarraxantes proporcionam uma fixa\u00e7\u00e3o segura sem a necessidade de roscas pr\u00e9-perfuradas.<\/p>\n<p style=\"margin-bottom: 15px;\">Entre os principais benef\u00edcios, destacam-se os testes padronizados de durabilidade, resist\u00eancia a falhas e compatibilidade com diversos materiais. A ades\u00e3o a essa norma minimiza riscos como a fragiliza\u00e7\u00e3o por hidrog\u00eanio e garante qualidade consistente na produ\u00e7\u00e3o. Para otimizar o uso, os engenheiros devem integrar essas especifica\u00e7\u00f5es aos processos de projeto e controle de qualidade.<\/p>\n<\/div>\n<div style=\"margin-bottom: 30px;\">\n<h2 style=\"color: #333; font-size: 1.5em; border-bottom: 2px solid #ddd; padding-bottom: 10px;\">Materiais<\/h2>\n<p style=\"margin-bottom: 15px;\">Os parafusos autoatarraxantes devem ser fabricados por conforma\u00e7\u00e3o a frio a partir de a\u00e7o cementado. A composi\u00e7\u00e3o qu\u00edmica fornecida na Tabela 1 serve apenas como guia, permitindo flexibilidade e mantendo as propriedades do n\u00facleo. Se o teor de boro for controlado pela adi\u00e7\u00e3o de tit\u00e2nio e\/ou alum\u00ednio para torn\u00e1-lo ineficaz, o teor de boro pode atingir at\u00e9 0,005%.<\/p>\n<p style=\"margin-bottom: 15px;\">Orienta\u00e7\u00f5es sobre a sele\u00e7\u00e3o de materiais:<\/p>\n<ul style=\"list-style-type: disc; padding-left: 20px; margin-bottom: 20px;\">\n<li>Garantir que o a\u00e7o atenda aos limites de carbono e mangan\u00eas para atingir a temperabilidade desejada.<\/li>\n<li>Evite impurezas que possam comprometer o endurecimento superficial.<\/li>\n<li>Verificar a composi\u00e7\u00e3o atrav\u00e9s da concha de medi\u00e7\u00e3o e conferir as an\u00e1lises para garantir a consist\u00eancia do lote.<\/li>\n<\/ul>\n<div class=\"table-container\" style=\"overflow-x: auto; margin-bottom: 20px;\">\n<h3 style=\"text-align: center; font-size: 1.2em; margin-bottom: 10px;\">Tabela 1: Composi\u00e7\u00e3o Qu\u00edmica<\/h3>\n<table style=\"border-collapse: collapse; width: 100%; margin-bottom: 20px;\">\n<thead>\n<tr style=\"background-color: #f2f2f2;\">\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\" rowspan=\"2\">An\u00e1lise<\/th>\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\" colspan=\"2\">Limites de composi\u00e7\u00e3o, %<\/th>\n<\/tr>\n<tr style=\"background-color: #f2f2f2;\">\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Carbono<\/th>\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Mangan\u00eas<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Concha<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">0.15~0.25<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">0.70~1.65<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Verificar<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">0.13~0.27<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">0.64~1.71<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<\/div>\n<div style=\"margin-bottom: 30px;\">\n<h2 style=\"color: #333; font-size: 1.5em; border-bottom: 2px solid #ddd; padding-bottom: 10px;\">Propriedades Mec\u00e2nicas e de Desempenho<\/h2>\n<p style=\"margin-bottom: 15px;\">A norma define os requisitos mec\u00e2nicos e de desempenho, com os m\u00e9todos de ensaio referenciados na Tabela 2. Os parafusos devem ser submetidos a cementa\u00e7\u00e3o e revenimento a uma temperatura m\u00ednima de 340 \u00b0C para atender a esses crit\u00e9rios.<\/p>\n<div class=\"table-container\" style=\"overflow-x: auto; margin-bottom: 20px;\">\n<h3 style=\"text-align: center; font-size: 1.2em; margin-bottom: 10px;\">Tabela 2: Propriedades Mec\u00e2nicas e de Desempenho<\/h3>\n<table style=\"border-collapse: collapse; width: 100%; margin-bottom: 20px;\">\n<thead>\n<tr style=\"background-color: #f2f2f2;\">\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Item de propriedade<\/th>\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Requisito t\u00e9cnico (cl\u00e1usula ou tabela)<\/th>\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">M\u00e9todo de teste (cl\u00e1usula)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Dureza do n\u00facleo<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">4.3<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">5.1<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Dureza da superf\u00edcie<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">4.3<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">5.2<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Profundidade do caso<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">4.4, Tabela 4<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">5.3<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Resist\u00eancia \u00e0 tor\u00e7\u00e3o<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">4.5, Tabela 3<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">5.4<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Sa\u00fade da cabe\u00e7a<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">4.6<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">5.5<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Teste de dire\u00e7\u00e3o<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">4.7, Tabela 3<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">5.6<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Fragiliza\u00e7\u00e3o por hidrog\u00eanio<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">4.8<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">5.7<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Dureza do n\u00facleo ap\u00f3s ret\u00eampera<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">4.9<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">5.8<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Resist\u00eancia \u00e0 trac\u00e7\u00e3o<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">4.10, Tabela 3<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">5.9<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">Tratamento t\u00e9rmico<\/h3>\n<p style=\"margin-bottom: 15px;\">Os parafusos acabados requerem cementa\u00e7\u00e3o e revenimento a uma temperatura m\u00ednima de 340 \u00b0C, cumprindo todas as propriedades da Tabela 3. Este processo aumenta a dureza da superf\u00edcie, mantendo a tenacidade do n\u00facleo, crucial para a resist\u00eancia ao torque.<\/p>\n<div class=\"table-container\" style=\"overflow-x: auto; margin-bottom: 20px;\">\n<h3 style=\"text-align: center; font-size: 1.2em; margin-bottom: 10px;\">Tabela 3: Requisitos mec\u00e2nicos e de desempenho<\/h3>\n<table style=\"border-collapse: collapse; width: 100%; margin-bottom: 20px;\">\n<thead>\n<tr style=\"background-color: #f2f2f2;\">\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Di\u00e2metro nominal da rosca (mm)<\/th>\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Resist\u00eancia m\u00ednima \u00e0 tor\u00e7\u00e3o (N\u00b7m)<\/th>\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Torque m\u00e1ximo de acionamento (N\u00b7m)<\/th>\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Resist\u00eancia m\u00ednima \u00e0 tra\u00e7\u00e3o (refer\u00eancia) (N)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">2<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">0.5<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">0.3<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">1940<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">2.5<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">1.2<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">0.6<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">3150<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">3<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">2.1<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">1.1<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">4680<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">3.5<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">3.4<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">1.7<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">6300<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">4<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">4.9<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">2.5<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">8170<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">5<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">10<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">5<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">13200<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">6<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">17<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">8.5<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">18700<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">8<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">42<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">21<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">34000<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">10<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">85<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">43<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">53900<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">12<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">150<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">75<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">78400<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">Dureza<\/h3>\n<p style=\"margin-bottom: 15px;\">A dureza do n\u00facleo deve ser de 290 a 370 HV10, com dureza superficial m\u00ednima de 450 HV0,3. Esses valores garantem o equil\u00edbrio entre ductilidade e resist\u00eancia ao desgaste, fatores vitais para aplica\u00e7\u00f5es de roscagem autoperfurante.<\/p>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">Profundidade do caso<\/h3>\n<p style=\"margin-bottom: 15px;\">A profundidade da camada endurecida deve estar em conformidade com a Tabela 4, proporcionando uma camada endurecida suficiente para desempenho de torque e desgaste sem fragilidade excessiva.<\/p>\n<div class=\"table-container\" style=\"overflow-x: auto; margin-bottom: 20px;\">\n<h3 style=\"text-align: center; font-size: 1.2em; margin-bottom: 10px;\">Tabela 4: Profundidade do caso<\/h3>\n<table style=\"border-collapse: collapse; width: 100%; margin-bottom: 20px;\">\n<thead>\n<tr style=\"background-color: #f2f2f2;\">\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\" rowspan=\"2\">Di\u00e2metro nominal da rosca (mm)<\/th>\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\" colspan=\"2\">Profundidade da caixa (mm)<\/th>\n<\/tr>\n<tr style=\"background-color: #f2f2f2;\">\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Min<\/th>\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">M\u00e1ximo<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">2, 2.5<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">0.04<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">0.12<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">3, 3.5<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">0.05<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">0.18<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">4, 5<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">0.1<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">0.25<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">6, 8<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">0.15<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">0.28<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">10, 12<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">0.15<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">0.32<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">Resist\u00eancia \u00e0 tor\u00e7\u00e3o<\/h3>\n<p style=\"margin-bottom: 15px;\">Resist\u00eancia \u00e0 tor\u00e7\u00e3o conforme a Tabela 3; a falha n\u00e3o deve ocorrer nas roscas fixadas. Este teste simula as tens\u00f5es reais de instala\u00e7\u00e3o.<\/p>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">Sa\u00fade da cabe\u00e7a<\/h3>\n<p style=\"margin-bottom: 15px;\">N\u00e3o foram observadas fissuras na jun\u00e7\u00e3o cabe\u00e7a-haste quando a face de apoio se deformou em um \u00e2ngulo de 7\u00b0. O teste \u00e9 v\u00e1lido mesmo que a falha ocorra na primeira rosca, desde que a cabe\u00e7a permane\u00e7a intacta.<\/p>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">Capacidade de forma\u00e7\u00e3o de rosca<\/h3>\n<p style=\"margin-bottom: 15px;\">Os parafusos devem formar roscas internas correspondentes sem deforma\u00e7\u00e3o permanente, com torque de aperto n\u00e3o superior aos valores da Tabela 3. As roscas formadas devem aceitar roscas externas com toler\u00e2ncia GB\/T 197 6h e suportar cargas de grau 8 conforme GB\/T 3098.2.<\/p>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">Resist\u00eancia \u00e0 fragiliza\u00e7\u00e3o por hidrog\u00eanio<\/h3>\n<p style=\"margin-bottom: 15px;\">Parafusos galvanizados requerem revis\u00e3o do processo conforme GB\/T 3098.17 para controle da fragiliza\u00e7\u00e3o por hidrog\u00eanio. Ap\u00f3s a galvaniza\u00e7\u00e3o, deve-se realizar a expuls\u00e3o de hidrog\u00eanio conforme GB\/T 5267. Recomenda-se o uso de revestimentos n\u00e3o eletrol\u00edticos de zinco em flocos conforme ISO 10683.<\/p>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">Dureza do n\u00facleo ap\u00f3s ret\u00eampera<\/h3>\n<p style=\"margin-bottom: 15px;\">A queda na dureza ap\u00f3s o revenido n\u00e3o deve exceder 20 HV, garantindo a estabilidade em servi\u00e7o.<\/p>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">Resist\u00eancia \u00e0 trac\u00e7\u00e3o<\/h3>\n<p style=\"margin-bottom: 15px;\">Para parafusos \u226512 mm ou \u22653d, teste de tra\u00e7\u00e3o por acordo; os valores de refer\u00eancia na Tabela 3 orientam o desempenho esperado.<\/p>\n<\/div>\n<div style=\"margin-bottom: 30px;\">\n<h2 style=\"color: #333; font-size: 1.5em; border-bottom: 2px solid #ddd; padding-bottom: 10px;\">M\u00e9todos de teste<\/h2>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">Teste de dureza do n\u00facleo<\/h3>\n<p style=\"margin-bottom: 15px;\">Me\u00e7a na metade do raio da se\u00e7\u00e3o transversal, afastando-se da extremidade, pelo di\u00e2metro menor, conforme GB\/T 4340.1. Isso verifica a tenacidade interna.<\/p>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">Teste de dureza superficial<\/h3>\n<p style=\"margin-bottom: 15px;\">Rotina: Na extremidade, haste ou cabe\u00e7a, conforme GB\/T 4340.1, ap\u00f3s a remo\u00e7\u00e3o do revestimento. Arbitragem: Microdureza Vickers HV0,1 no perfil com di\u00e2metro \u22654 mm, a \u22650,05 mm da borda; negociar para &lt;4 mm.<\/p>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">Teste de profundidade do caso<\/h3>\n<p style=\"margin-bottom: 15px;\">Dist\u00e2ncia da superf\u00edcie ao ponto onde a dureza = n\u00facleo + 30 HV0,3; a arbitragem utiliza a microdureza HV0,3 em amostra metalogr\u00e1fica preparada.<\/p>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">Teste de resist\u00eancia \u00e0 tor\u00e7\u00e3o<\/h3>\n<p style=\"margin-bottom: 15px;\">Fixe a amostra com \u22652 roscas completas no dispositivo de fixa\u00e7\u00e3o, \u22652 expostas; aplique torque at\u00e9 a ruptura e registre o valor conforme a Tabela 3.<\/p>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">Teste de sanidade cerebral<\/h3>\n<p style=\"margin-bottom: 15px;\">Insira na cunha com di\u00e2metro do furo igual ao nominal +0,05 mm (\u2264M6) ou +0,1 mm (&gt;M6~M12); aplique carga axial at\u00e9 uma deforma\u00e7\u00e3o de 7\u00b0. N\u00e3o indicado para cabe\u00e7as escareadas. Se necess\u00e1rio, utilize golpes de martelo.<\/p>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">Teste de dire\u00e7\u00e3o<\/h3>\n<p style=\"margin-bottom: 15px;\">Insira o parafuso na placa de teste (a\u00e7o de baixo carbono, 140~180 HV30, espessura = di\u00e2metro nominal, furo conforme Tabela 5) at\u00e9 que pelo menos uma rosca fique saliente. For\u00e7a axial inicial \u226450 N (\u2264M5) ou \u2264100 N (&gt;M5); velocidade \u226430 rpm para fins de arbitragem. Adicione lubrificante, se necess\u00e1rio.<\/p>\n<div class=\"table-container\" style=\"overflow-x: auto; margin-bottom: 20px;\">\n<h3 style=\"text-align: center; font-size: 1.2em; margin-bottom: 10px;\">Tabela 5: Espessura da placa de teste e di\u00e2metros dos furos<\/h3>\n<table style=\"border-collapse: collapse; width: 100%; margin-bottom: 20px;\">\n<thead>\n<tr style=\"background-color: #f2f2f2;\">\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\" colspan=\"2\">Di\u00e2metro nominal da rosca (mm)<\/th>\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">2<\/th>\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">2.5<\/th>\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">3<\/th>\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">3.5<\/th>\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">4<\/th>\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">5<\/th>\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">6<\/th>\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">8<\/th>\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">10<\/th>\n<th style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">12<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\" colspan=\"2\">Espessura (mm)<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">2<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">2.5<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">3<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">3.5<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">4<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">5<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">6<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">8<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">10<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">12<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\" rowspan=\"2\">Di\u00e2metro do furo (mm)<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">M\u00e1ximo<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">1.825<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">2.275<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">2.775<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">3.18<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">3.68<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">4.53<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">5.43<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">7.336<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">9.236<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">11.143<\/td>\n<\/tr>\n<tr>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">Min<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">1.8<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">2.25<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">2.75<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">3.15<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">3.65<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">4.5<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">5.4<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">7.3<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">9.2<\/td>\n<td style=\"border: 1px solid #ddd; padding: 8px; text-align: left;\">11.1<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n<p style=\"margin-bottom: 15px;\">Nota: Toler\u00e2ncia da espessura da chapa de teste conforme GB\/T 709 para chapas de a\u00e7o laminado.<\/p>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">Teste de fragiliza\u00e7\u00e3o por hidrog\u00eanio<\/h3>\n<p style=\"margin-bottom: 15px;\">De acordo com GB\/T 3098.17, utiliza-se o m\u00e9todo de suporte paralelo para avaliar o controle do processo.<\/p>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">Teste de retemperagem<\/h3>\n<p style=\"margin-bottom: 15px;\">A 330 \u00b0C durante 1 h; a m\u00e9dia de tr\u00eas pontos de dureza do n\u00facleo difere em \u226420 HV antes\/depois. Apenas para fins de arbitragem.<\/p>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">Teste de tra\u00e7\u00e3o<\/h3>\n<p style=\"margin-bottom: 15px;\">Fixe com \u22656 roscas expostas; aplique carga axial \u226425 mm\/min at\u00e9 a ruptura. A ruptura ocorre na haste ou nas roscas, n\u00e3o na jun\u00e7\u00e3o da cabe\u00e7a; s\u00e3o necess\u00e1rias garras autocentrantes.<\/p>\n<\/div>\n<div style=\"margin-bottom: 30px;\">\n<h2 style=\"color: #333; font-size: 1.5em; border-bottom: 2px solid #ddd; padding-bottom: 10px;\">Chaves de torque<\/h2>\n<p style=\"margin-bottom: 15px;\">Para testes de tor\u00e7\u00e3o e acionamento, o erro \u00e9 \u2264\u00b13% do torque especificado. Dispositivos el\u00e9tricos equivalentes s\u00e3o permitidos; manual para arbitragem. A calibra\u00e7\u00e3o garante uma avalia\u00e7\u00e3o precisa do desempenho do parafuso sob carga.<\/p>\n<\/div>\n<div style=\"margin-bottom: 30px;\">\n<h2 style=\"color: #333; font-size: 1.5em; border-bottom: 2px solid #ddd; padding-bottom: 10px;\">Marca\u00e7\u00e3o<\/h2>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">C\u00f3digo de marca\u00e7\u00e3o<\/h3>\n<p style=\"margin-bottom: 15px;\">Parafusos autoatarraxantes temperados e revenidos, marcados com \u201c-O-\u201d.<\/p>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">Identifica\u00e7\u00e3o<\/h3>\n<p style=\"margin-bottom: 15px;\">\u00c9 necess\u00e1ria marca\u00e7\u00e3o em relevo ou embutida para cabe\u00e7as sextavadas ou hexalobulares com di\u00e2metro nominal \u2265 5 mm, preferencialmente na cabe\u00e7a. Para outros tipos, mediante acordo.<\/p>\n<h3 style=\"font-size: 1.2em; margin-top: 20px; margin-bottom: 10px;\">Marca de identifica\u00e7\u00e3o do fabricante<\/h3>\n<p style=\"margin-bottom: 15px;\">Obrigat\u00f3rio para todos os produtos marcados, garantindo rastreabilidade e controle de qualidade.<\/p>\n<\/div>\n<div style=\"margin-bottom: 30px;\">\n<h2 style=\"color: #333; font-size: 1.5em; border-bottom: 2px solid #ddd; padding-bottom: 10px;\">Perguntas frequentes<\/h2>\n<ol style=\"list-style-type: decimal; padding-left: 20px; margin-bottom: 20px;\">\n<li style=\"margin-bottom: 15px;\"><strong>Qual a finalidade do endurecimento superficial em parafusos autoatarraxantes?<\/strong><br \/>\nO endurecimento superficial proporciona uma superf\u00edcie dura para a forma\u00e7\u00e3o da rosca e resist\u00eancia ao desgaste, mantendo o n\u00facleo d\u00factil para evitar falhas fr\u00e1geis sob torque ou tens\u00e3o, conforme especificado nas cl\u00e1usulas 4.2 e 4.3.<\/li>\n<li style=\"margin-bottom: 15px;\"><strong>Como mitigar a fragiliza\u00e7\u00e3o por hidrog\u00eanio em parafusos galvanizados?<\/strong><br \/>\nImplementar controles de processo conforme GB\/T 3098.17, realizar a expuls\u00e3o de hidrog\u00eanio p\u00f3s-revestimento conforme GB\/T 5267 e considerar revestimentos n\u00e3o eletrol\u00edticos, como zinco em flocos, conforme ISO 10683, para reduzir o risco.<\/li>\n<li style=\"margin-bottom: 15px;\"><strong>E se um parafuso falhar no teste de resist\u00eancia \u00e0 tor\u00e7\u00e3o na \u00e1rea de fixa\u00e7\u00e3o?<\/strong><br \/>\nA falha nas roscas fixadas invalida o teste; assegure-se de que a fixa\u00e7\u00e3o seja feita corretamente, com pelo menos duas roscas totalmente fixadas e expostas, conforme 5.4, para avaliar com precis\u00e3o a resist\u00eancia do material.<\/li>\n<li style=\"margin-bottom: 15px;\"><strong>Os ensaios de tra\u00e7\u00e3o s\u00e3o obrigat\u00f3rios para todos os parafusos autoatarraxantes?<\/strong><br \/>\nN\u00e3o, apenas para comprimentos \u226512 mm ou \u22653d mediante acordo entre fornecedor e comprador; os valores da Tabela 3 s\u00e3o de refer\u00eancia, enfatizando as propriedades de tor\u00e7\u00e3o e de acionamento como m\u00e9tricas principais.<\/li>\n<li style=\"margin-bottom: 15px;\"><strong>Como a profundidade da camada de cementa\u00e7\u00e3o afeta o desempenho do parafuso?<\/strong><br \/>\nUma profundidade insuficiente pode levar ao desgaste prematuro ou \u00e0 falha na forma\u00e7\u00e3o da rosca, enquanto uma profundidade excessiva aumenta a fragilidade; siga os limites da Tabela 4 para obter propriedades equilibradas em aplica\u00e7\u00f5es como montagens de a\u00e7o.<\/li>\n<li style=\"margin-bottom: 15px;\"><strong>Que equipamento \u00e9 recomendado para testes de arbitragem?<\/strong><br \/>\nUtilize chaves dinamom\u00e9tricas manuais com precis\u00e3o de \u00b13% para testes de tor\u00e7\u00e3o e acionamento, e microdureza Vickers para avalia\u00e7\u00e3o da superf\u00edcie e da profundidade da camada endurecida, a fim de garantir resultados precisos e imparciais.<\/li>\n<\/ol>\n<\/div>\n<p>&nbsp;<\/p>","protected":false},"excerpt":{"rendered":"<p>Article Outline This article provides a structured overview of the GB\/T 3098.7-2000 standard, optimized for clarity and practical application in mechanical engineering. The outline ensures comprehensive coverage of key aspects: Introduction: Scope and significance of the standard. Materials: Chemical composition and manufacturing guidelines. Mechanical and Performance Properties: Detailed requirements including hardness, torque, and more. Test [&hellip;]<\/p>","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[220],"tags":[],"class_list":["post-5711","post","type-post","status-publish","format-standard","hentry","category-technical-documentation-and-references"],"_links":{"self":[{"href":"https:\/\/korea-transmission.com\/pt\/wp-json\/wp\/v2\/posts\/5711","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/korea-transmission.com\/pt\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/korea-transmission.com\/pt\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/korea-transmission.com\/pt\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/korea-transmission.com\/pt\/wp-json\/wp\/v2\/comments?post=5711"}],"version-history":[{"count":2,"href":"https:\/\/korea-transmission.com\/pt\/wp-json\/wp\/v2\/posts\/5711\/revisions"}],"predecessor-version":[{"id":5713,"href":"https:\/\/korea-transmission.com\/pt\/wp-json\/wp\/v2\/posts\/5711\/revisions\/5713"}],"wp:attachment":[{"href":"https:\/\/korea-transmission.com\/pt\/wp-json\/wp\/v2\/media?parent=5711"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/korea-transmission.com\/pt\/wp-json\/wp\/v2\/categories?post=5711"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/korea-transmission.com\/pt\/wp-json\/wp\/v2\/tags?post=5711"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}