{"id":9468,"date":"2025-12-29T15:56:07","date_gmt":"2025-12-29T07:56:07","guid":{"rendered":"https:\/\/www.cncmachiningshops.com\/?p=9468"},"modified":"2026-01-01T10:21:52","modified_gmt":"2026-01-01T02:21:52","slug":"45-steel","status":"publish","type":"post","link":"https:\/\/www.cncmachiningshops.com\/pt\/45-steel\/","title":{"rendered":"A\u00e7o 45# (C45 \/ 1045 \/ S45C): Composi\u00e7\u00e3o Qu\u00edmica, Propriedades Mec\u00e2nicas e Aplica\u00e7\u00f5es de Engenharia"},"content":{"rendered":"
\n

Em engenharia mec\u00e2nica, o a\u00e7o 45# \u00e9 o melhor a\u00e7o de m\u00e9dio carbono. Tamb\u00e9m \u00e9 conhecido como AISI 1045, C45 ou S45C em todo o mundo. Tem sido popular por muito tempo porque possui um equil\u00edbrio de engenharia bem definido: \u00e9 mais resistente que os a\u00e7os estruturais de baixo carbono, pode se tornar mais tenaz atrav\u00e9s de tratamento t\u00e9rmico e \u00e9 muito econ\u00f4mico.<\/span><\/p>\n

O nome \u201c45\u201d vem do fato de que possui cerca de 0,45% de carbono em peso. Esta \u00e9 a \u00fanica coisa que tem mais efeito sobre como ele se comporta. Quando o teor de carbono \u00e9 t\u00e3o alto, o a\u00e7o pode ser temperado e revenido para se tornar muito mais resistente e duro do que a\u00e7os como Q235 ou 1018. Os a\u00e7os de baixo carbono, por outro lado, obt\u00eam sua resist\u00eancia principalmente do tamanho de suas se\u00e7\u00f5es.<\/span><\/p>\n

Para eixos, engrenagens, bielas, fusos e outras pe\u00e7as mec\u00e2nicas, o a\u00e7o 45# \u00e9 a escolha mais comum. \u00c9 preferido quando a t\u00eampera total ou a t\u00eampera superficial \u00e9 necess\u00e1ria, mas os a\u00e7os ligados (como o 4140) seriam excessivos ou muito caros.<\/span><\/p>\n

Este artigo analisa o a\u00e7o 45# como material de engenharia. Ele conecta coisas como composi\u00e7\u00e3o qu\u00edmica, como ele responde ao tratamento t\u00e9rmico, qu\u00e3o f\u00e1cil \u00e9 usin\u00e1-lo e como escolher o melhor material para o seu projeto.<\/span><\/p>\n

O que \u00e9 o a\u00e7o 45#? Este artigo explicar\u00e1 as regras para nome\u00e1-lo e como ele se compara a outros tipos de a\u00e7o ao redor do mundo.<\/span><\/h2>\n

Precisamos analisar as normas que comp\u00f5em o a\u00e7o 45# para entend\u00ea-lo. A norma nacional chinesa GB\/T 699, que abrange a\u00e7os estruturais de carbono de alta qualidade, o define.<\/span><\/p>\n

A Regra para Nomenclatura<\/span><\/h3>\n

A regra \u00e9 simples:<\/span><\/p>\n

    \n
  • \n

    \u201c45\u201d:<\/span><\/strong> Isso significa que o teor m\u00e9dio de carbono \u00e9 0,45%.<\/span><\/p>\n<\/li>\n

  • \n

    \u201c#\u201d:<\/span><\/strong> Um sufixo comum no jarg\u00e3o industrial chin\u00eas que significa \u201cN\u00famero\u201d ou \u201cGrau\u201d.\u201d<\/span><\/p>\n<\/li>\n<\/ul>\n

    Graus equivalentes em outros pa\u00edses<\/span><\/h3>\n

    O a\u00e7o 45# \u00e9 um tipo de a\u00e7o de m\u00e9dio carbono conhecido em todo o mundo. Embora sejam quimicamente semelhantes, as propriedades finais dependem de como s\u00e3o tratados termicamente.<\/span><\/p>\n

    Tabela 1: Equivalentes ao redor do mundo<\/span><\/strong><\/p>\n

    \n\n\n\n\n\n\n\n
    Regi\u00e3o \/ Padr\u00e3o<\/span><\/td>\nDesigna\u00e7\u00e3o do Grau<\/span><\/td>\nNota<\/span><\/td>\n<\/tr>\n
    China (GB)<\/span><\/strong><\/td>\n45#<\/span><\/td>\num tipo de a\u00e7o estrutural de carbono de alta qualidade.<\/span><\/td>\n<\/tr>\n
    EUA (ASTM\/SAE)<\/span><\/strong><\/td>\nAISI 1045<\/span><\/td>\nO tipo mais comum de a\u00e7o de m\u00e9dio carbono na Am\u00e9rica do Norte.<\/span><\/td>\n<\/tr>\n
    Europa (EN)<\/span><\/strong><\/td>\nC45 \/ 1.0503<\/span><\/td>\nMuito usado em autom\u00f3veis e m\u00e1quinas.<\/span><\/td>\n<\/tr>\n
    Jap\u00e3o (JIS)<\/span><\/strong><\/td>\nS45C<\/span><\/td>\nO grau mais comum para pe\u00e7as de m\u00e1quinas na \u00c1sia.<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

    Esclarecimento de Engenharia:<\/span><\/strong> \u201cEquivalente\u201d n\u00e3o significa a mesma coisa. Uma chapa C45 da Alemanha pode ter limites de mangan\u00eas diferentes de uma barra 45# da China. Sempre verifique os certificados espec\u00edficos do fabricante (MTRs) para usos importantes.<\/span><\/p>\n

    A composi\u00e7\u00e3o qu\u00edmica do a\u00e7o 45# e o que ela significa para a metalurgia<\/span><\/h2>\n

    O design qu\u00edmico centrado no carbono do a\u00e7o 45# determina qu\u00e3o bem ele funciona. Ele usa Carbono para resist\u00eancia e Mangan\u00eas para endurecimento.<\/span><\/p>\n

    Tabela 2: Composi\u00e7\u00e3o Qu\u00edmica Comum (wt.%)<\/span><\/strong><\/p>\n

    \n\n\n\n\n\n\n\n\n\n
    Elemento<\/span><\/td>\nFaixa<\/span><\/td>\nImport\u00e2ncia Metal\u00fargica<\/span><\/td>\n<\/tr>\n
    Carbono (C)<\/span><\/strong><\/td>\n0.42\u20130.50<\/span><\/td>\nA principal coisa que torna as coisas resistentes, duras e capazes de endurecer.<\/span><\/td>\n<\/tr>\n
    Mangan\u00eas (Mn)<\/span><\/strong><\/td>\n0.50\u20130.80<\/span><\/td>\nTorna as coisas mais resistentes e duras; ajuda com a t\u00eampera uniforme.<\/span><\/td>\n<\/tr>\n
    Sil\u00edcio (Si)<\/span><\/strong><\/td>\n0.17\u20130.37<\/span><\/td>\nremove o oxig\u00eanio e adiciona um pouco de resist\u00eancia.<\/span><\/td>\n<\/tr>\n
    F\u00f3sforo (P)<\/span><\/strong><\/td>\n\u2264 0,035<\/span><\/td>\numa impureza. Excesso dela reduz a tenacidade (fragilidade a frio).<\/span><\/td>\n<\/tr>\n
    Enxofre (S)<\/span><\/strong><\/td>\n\u2264 0,035<\/span><\/td>\nImpureza. Torna as coisas mais f\u00e1ceis de trabalhar (bom) e mais dif\u00edceis de quebrar (ruim).<\/span><\/td>\n<\/tr>\n
    Cromo\/N\u00edquel<\/span><\/strong><\/td>\n\u2264 0,25<\/span><\/td>\nResiduais. N\u00e3o adicionados intencionalmente (como a\u00e7os ligados).<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

    A fun\u00e7\u00e3o do carbono (0,45%)<\/span><\/h3>\n
      \n
    • \n

      Endurecimento:<\/span><\/strong> Isso permite a forma\u00e7\u00e3o de Martensita quando o a\u00e7o \u00e9 resfriado, o que o torna mais duro. A superf\u00edcie pode atingir 50+ HRC e o n\u00facleo pode atingir 20-30 HRC.<\/span><\/p>\n<\/li>\n

    • \n

      Compensa\u00e7\u00e3o:<\/span><\/strong> Quanto mais carbono houver, mais dif\u00edcil \u00e9 soldar. H\u00e1 uma chance real de que a Zona Afetada pelo Calor (ZAC) rache.<\/span><\/p>\n<\/li>\n<\/ul>\n

      Por que o 45# N\u00e3o \u00e9 um A\u00e7o Ligado<\/span><\/h3>\n

      Ele n\u00e3o possui Cromo, Molibd\u00eanio ou Van\u00e1dio suficientes. A mudan\u00e7a de fase Ferro-Carbono \u00e9 o que lhe confere suas propriedades. Isso significa que ele n\u00e3o pode endurecer se\u00e7\u00f5es espessas como o 4140, o que o torna menos temper\u00e1vel.<\/span><\/p>\n

      Microestrutura e Mecanismos de Resist\u00eancia<\/span><\/h2>\n

      A microestrutura do a\u00e7o 45# afeta diretamente seu comportamento mec\u00e2nico.<\/span><\/p>\n

        \n
      1. \n

        Normalizado ou Recozido (Ferrita-Perlita)<\/span><\/strong><\/p>\n

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        • \n

          A estrutura \u00e9 composta tanto de Ferrita mole quanto de Perlita dura quando \u00e9 laminado ou normalizado.<\/span><\/p>\n<\/li>\n

        • \n

          Resultado:<\/span><\/strong> F\u00e1cil de usinar, resist\u00eancia m\u00e9dia e boa ductilidade. \u00c9 assim que o material em barra \u00e9 normalmente fornecido.<\/span><\/p>\n<\/li>\n<\/ul>\n<\/li>\n

        • \n

          Temperado e revenido (martensita revenida)<\/span><\/strong><\/p>\n

            \n
          • \n

            A estrutura se transforma em Martensita Revenida ap\u00f3s o aquecimento.<\/span><\/p>\n<\/li>\n

          • \n

            Resultado:<\/span><\/strong> Resistente, duro e tenaz, mas n\u00e3o excessivamente tenaz. Este \u00e9 o estado em que eixos e engrenagens acabados se encontram.<\/span><\/p>\n<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n

            Propriedades f\u00edsicas e mec\u00e2nicas do a\u00e7o 45#<\/span><\/h2>\n

            Dependendo do tratamento t\u00e9rmico, as propriedades podem variar muito. Os engenheiros precisam registrar a condi\u00e7\u00e3o no desenho.<\/span><\/p>\n

            As Condi\u00e7\u00f5es Afetam as Propriedades Mec\u00e2nicas<\/span><\/h3>\n

            Tabela 3: Propriedades Mec\u00e2nicas Comuns<\/span><\/strong><\/p>\n

            \n\n\n\n\n\n\n
            Estado<\/span><\/td>\nResist\u00eancia ao escoamento (MPa)<\/span><\/td>\nResist\u00eancia \u00e0 tra\u00e7\u00e3o (MPa)<\/span><\/td>\nDureza<\/span><\/td>\nAlongamento<\/span><\/td>\n<\/tr>\n
            Recozido<\/span><\/strong><\/td>\n~310<\/span><\/td>\n~570<\/span><\/td>\n~170 HB<\/span><\/td>\n16%<\/span><\/td>\n<\/tr>\n
            Normalizado<\/span><\/strong><\/td>\n~360<\/span><\/td>\n~600<\/span><\/td>\n~200 HB<\/span><\/td>\n16%<\/span><\/td>\n<\/tr>\n
            Temperado e revenido<\/span><\/strong><\/td>\n500\u2013600+<\/span><\/td>\n700\u2013850+<\/span><\/td>\n22\u201355 HRC<\/span><\/td>\n12%<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

            Nota:<\/span><\/strong> A T\u00eampera por Indu\u00e7\u00e3o pode tornar a superf\u00edcie dura o suficiente para atingir 55 HRC, mas o n\u00facleo geralmente \u00e9 mais macio.<\/span><\/p>\n

            Caracter\u00edsticas F\u00edsicas<\/span><\/h3>\n
              \n
            • \n

              Densidade:<\/span><\/strong> 7,85 g\/cm\u00b3<\/span><\/p>\n<\/li>\n

            • \n

              M\u00f3dulo de Elasticidade:<\/span><\/strong> 206 GPa (A rigidez permanece a mesma independentemente da temperatura).<\/span><\/p>\n<\/li>\n

            • \n

              Expans\u00e3o T\u00e9rmica:<\/span><\/strong> cerca de 11,5 \u00b5m\/m\u00b7\u00b0C.<\/span><\/p>\n<\/li>\n<\/ul>\n

              O que acontece quando voc\u00ea faz tratamento t\u00e9rmico no a\u00e7o 45#?<\/span><\/h2>\n

              A principal alavanca de valor para o a\u00e7o 45# \u00e9 o tratamento t\u00e9rmico.<\/span><\/p>\n

                \n
              1. \n

                Normaliza\u00e7\u00e3o (Refino)<\/span><\/strong><\/p>\n

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                • \n

                  Processo:<\/span><\/strong> Aque\u00e7a a cerca de 840\u00b0C e depois resfrie ao ar.<\/span><\/p>\n<\/li>\n

                • \n

                  Objetivo:<\/span><\/strong> Melhora o tamanho dos gr\u00e3os ap\u00f3s o forjamento. Proporciona \u00e0 usinagem um ponto de partida consistente.<\/span><\/p>\n<\/li>\n<\/ul>\n<\/li>\n

                • \n

                  T\u00eampera e revenimento (tornando mais resistente)<\/span><\/strong><\/p>\n

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                  • \n

                    Processo:<\/span><\/strong> Aque\u00e7a a cerca de 840\u00b0C, resfrie em \u00e1gua ou \u00f3leo, e depois reveja a 500\u00b0C a 600\u00b0C.<\/span><\/p>\n<\/li>\n

                  • \n

                    Objetivo:<\/span><\/strong> Torna o material mais resistente. A t\u00eampera em \u00e1gua \u00e9 arriscada (pode causar trincas), mas funciona para o 45#. O \u00f3leo \u00e9 mais seguro, mas n\u00e3o torna o metal t\u00e3o duro.<\/span><\/p>\n<\/li>\n<\/ul>\n<\/li>\n

                  • \n

                    Endurecimento por indu\u00e7\u00e3o (desgaste na superf\u00edcie)<\/span><\/strong><\/p>\n

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                    • \n

                      Processo:<\/span><\/strong> Aque\u00e7a a superf\u00edcie com alta frequ\u00eancia, depois borrife com \u00e1gua para resfri\u00e1-la.<\/span><\/p>\n<\/li>\n

                    • \n

                      Objetivo:<\/span><\/strong> Mantenha o n\u00facleo tenaz e d\u00factil enquanto torna a camada superficial dura e resistente ao desgaste (50\u201355 HRC). \u00d3timo para engrenagens e eixos retos.<\/span><\/p>\n<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n

                      Diretrizes para Processamento e Usinabilidade do CNC<\/span><\/h2>\n

                      m\u00e1quinas feitas de a\u00e7o 45# \u00c9 resistente, mas n\u00e3o tanto quanto a\u00e7os de baixo carbono como o 1018.<\/span><\/p>\n

                      Caracter\u00edsticas de usinabilidade<\/span><\/h3>\n
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                      • \n

                        Normalizado:<\/span><\/strong> Boa usinabilidade (classifica\u00e7\u00e3o de aproximadamente 55%). O teor de perlita faz com que os cavacos se quebrem muito bem.<\/span><\/p>\n<\/li>\n

                      • \n

                        T\u00eampera<\/span><\/strong> torna muito mais dif\u00edcil de usinar. Ap\u00f3s o endurecimento, geralmente \u00e9 necess\u00e1rio fazer acabamento ou retifica\u00e7\u00e3o.<\/span><\/p>\n<\/li>\n<\/ul>\n

                        Recomenda\u00e7\u00f5es para CNC<\/span><\/h3>\n
                          \n
                        • \n

                          Ferramentas padr\u00e3o<\/span><\/strong> \u00e9 metal duro revestido (TiCN\/AlTiN).<\/span><\/p>\n<\/li>\n

                        • \n

                          Avan\u00e7os e velocidades:<\/span><\/strong> N\u00e3o muito r\u00e1pido. Avan\u00e7os agressivos ajudam os cavacos a se quebrar.<\/span><\/p>\n<\/li>\n

                        • \n

                          Acabamento da superf\u00edcie:<\/span><\/strong> Pode obter \u00f3timos acabamentos (Ra 1,6 \u00b5m ou melhor) porque n\u00e3o \u00e9 \u201cpegajoso\u201d como o a\u00e7o de baixo carbono.<\/span><\/p>\n<\/li>\n<\/ul>\n

                          Controle da Soldabilidade e da Zona Afetada pelo Calor (ZAC)<\/span><\/h2>\n

                          Aviso:<\/span><\/strong> O a\u00e7o 45# pode ser soldado, mas n\u00e3o cede facilmente.<\/span><\/p>\n

                          O Risco da Soldagem<\/span><\/h3>\n

                          O teor de carbono de 0,45% torna a martensita fr\u00e1gil na ZAC quando ela esfria rapidamente. Isso causa trincas a frio.<\/span><\/p>\n

                          Partes Importantes de uma Especifica\u00e7\u00e3o de Procedimento de Soldagem (EPS)<\/span><\/h3>\n
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                            Pr\u00e9-aquecimento:<\/span><\/strong> Muito importante. Antes de soldar, aque\u00e7a a pe\u00e7a entre 150 e 250 graus Celsius para retardar o processo de resfriamento.<\/span><\/p>\n<\/li>\n

                          • \n

                            Mantenha a pe\u00e7a aquecida entre passes.<\/span><\/p>\n<\/li>\n

                          • \n

                            Tratamento T\u00e9rmico P\u00f3s-Soldagem (TTPS):<\/span><\/strong> Para evitar que a solda trinque durante o uso, \u00e9 altamente recomend\u00e1vel aliviar as tens\u00f5es ou revenir.<\/span><\/p>\n<\/li>\n

                          • \n

                            Metal de Adi\u00e7\u00e3o:<\/span><\/strong> Voc\u00ea deve usar eletrodos de baixo hidrog\u00eanio.<\/span><\/p>\n<\/li>\n<\/ul>\n

                            Conclus\u00e3o para engenheiros:<\/span><\/strong> Se uma estrutura for fortemente soldada, como uma estrutura complexa, voc\u00ea pode querer usar Q235 ou Q345 (baixa liga) em vez de 45# para reduzir o risco de fissuras.<\/span><\/p>\n

                            Um Guia para Escolher o A\u00e7o 45# em Vez de Outros A\u00e7os Comuns<\/span><\/h2>\n

                            Para escolher o a\u00e7o certo, voc\u00ea precisa encontrar um equil\u00edbrio entre resist\u00eancia, custo e facilidade de usinagem.<\/span><\/p>\n

                            Tabela 4: 45# vs. Outras Marcas<\/span><\/strong><\/p>\n

                            \n\n\n\n\n\n\n\n\n\n
                            Recurso<\/span><\/td>\n45# (1045)<\/span><\/td>\nQ235 (A\u00e7o Doce)<\/span><\/td>\n4140 (A\u00e7o Liga)<\/span><\/td>\n<\/tr>\n
                            Carbono<\/span><\/strong><\/td>\nM\u00e9dio (0,45%)<\/span><\/td>\nBaixo (<0,22%)<\/span><\/td>\nM\u00e9dio (0,40%)<\/span><\/td>\n<\/tr>\n
                            For\u00e7a<\/span><\/strong><\/td>\nModerado a elevado<\/span><\/td>\nBaixo<\/span><\/td>\nMuito alto<\/span><\/td>\n<\/tr>\n
                            Temperabilidade<\/span><\/strong><\/td>\nSuperf\u00edcie\/Se\u00e7\u00e3o Fina<\/span><\/td>\nNenhum<\/span><\/td>\nSe\u00e7\u00e3o Profunda\/Espessa<\/span><\/td>\n<\/tr>\n
                            Soldabilidade<\/span><\/strong><\/td>\nRazo\u00e1vel (Pr\u00e9-aquecimento)<\/span><\/td>\nBom<\/span><\/td>\nDif\u00edcil<\/span><\/td>\n<\/tr>\n
                            Custo<\/span><\/strong><\/td>\nBaixa\/M\u00e9dia<\/span><\/td>\nMais baixo<\/span><\/td>\nAlto<\/span><\/td>\n<\/tr>\n
                            Utiliza\u00e7\u00e3o t\u00edpica<\/span><\/strong><\/td>\nEixos, engrenagens<\/span><\/td>\nSuportes, estruturas<\/span><\/td>\nEixos para Servi\u00e7o Pesado<\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

                            Como escolher<\/span><\/h3>\n
                              \n
                            • \n

                              Utiliza\u00e7\u00e3o <\/span>45#<\/span><\/strong> se voc\u00ea precisa de algo mais resistente ou que suporte melhor o desgaste (t\u00eampera). Use <\/span>Q235<\/span><\/strong> para soldagem e constru\u00e7\u00e3o de coisas que n\u00e3o se movem.<\/span><\/p>\n<\/li>\n

                            • \n

                              Se a pe\u00e7a for espessa (mais de 50 mm) e precisar ser dura em toda a sua extens\u00e3o, use <\/span>4140<\/span><\/strong>. O 45# s\u00f3 endurece pr\u00f3ximo \u00e0 superf\u00edcie.<\/span><\/p>\n<\/li>\n<\/ul>\n

                              Usos Comuns do A\u00e7o 45# na Engenharia<\/span><\/h2>\n

                              A ind\u00fastria de m\u00e1quinas \u00e9 a que mais depende do 45#.<\/span><\/p>\n

                                \n
                              • \n

                                Movimento:<\/span><\/strong> Eixos lineares, hastes guia e fusos.<\/span><\/p>\n<\/li>\n

                              • \n

                                Transmiss\u00e3o de pot\u00eancia:<\/span><\/strong> Engrenagens, coroas dentadas, virabrequins e bielas.<\/span><\/p>\n<\/li>\n

                              • \n

                                Fixadores:<\/span><\/strong> Parafusos com alta resist\u00eancia (material base equivalente ao Grau 8.8).<\/span><\/p>\n<\/li>\n

                              • \n

                                Ferramentas:<\/span><\/strong> dispositivos de fixa\u00e7\u00e3o, conjuntos de matrizes e bases de moldes.<\/span><\/p>\n<\/li>\n

                              • \n

                                Hidr\u00e1ulica:<\/span><\/strong> Hastes de cilindro que foram cromadas e endurecidas por indu\u00e7\u00e3o.<\/span><\/p>\n<\/li>\n<\/ul>\n

                                Resumo\u2014O que os Engenheiros Aprenderam<\/span><\/h2>\n

                                O a\u00e7o 45# \u00e9 um material barato e \u00fatil para engenharia.<\/span><\/p>\n

                                Pontos importantes:<\/span><\/strong><\/p>\n

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                                • \n

                                  Sintoniz\u00e1vel:<\/span><\/strong> Pode ser macio (recozido) ou duro (temperado).<\/span><\/p>\n<\/li>\n

                                • \n

                                  Endurec\u00edvel em superf\u00edcie:<\/span><\/strong> \u00d3timo para t\u00eampera por indu\u00e7\u00e3o (cerca de 55 HRC).<\/span><\/p>\n<\/li>\n

                                • \n

                                  Amig\u00e1vel \u00e0 Usinagem:<\/span><\/strong> A vida \u00fatil da ferramenta e o acabamento superficial s\u00e3o ambos bons.<\/span><\/p>\n<\/li>\n

                                • \n

                                  Tenha cuidado ao soldar:<\/span><\/strong> Voc\u00ea precisa fazer pr\u00e9-aquecimento e p\u00f3s-aquecimento para evitar fissuras.<\/span><\/p>\n<\/li>\n<\/ul>\n

                                  Engenheiros podem fabricar pe\u00e7as mec\u00e2nicas fortes e duradouras por muito menos dinheiro do que os a\u00e7os liga, se souberem o que o tratamento t\u00e9rmico pode e n\u00e3o pode fazer.<\/span><\/p>\n

                                  Perguntas frequentes<\/span><\/h2>\n

                                  P: O a\u00e7o 1045 \u00e9 o mesmo que o 45#?<\/span><\/strong>
                                  R: Sim. Em termos de como funcionam, eles s\u00e3o iguais. A norma chinesa GB \u00e9 45#, e a norma americana AISI\/SAE \u00e9 1045. Ambos s\u00e3o a\u00e7os com cerca de 0,45% de carbono.<\/span><\/p>\n

                                  P: O a\u00e7o 45# enferruja?<\/span><\/strong>
                                  R: Sim. \u00c9 um a\u00e7o carbono simples sem cromo em sua composi\u00e7\u00e3o. Precisa ser protegido com \u00f3leo, tinta, galvanoplastia ou oxida\u00e7\u00e3o negra.<\/span><\/p>\n

                                  P: \u00c9 poss\u00edvel soldar o a\u00e7o 45#?<\/span><\/strong>
                                  R: Sim, mas voc\u00ea precisa aquec\u00ea-lo primeiro para evitar fissuras. N\u00e3o solda t\u00e3o bem quanto o Q235 ou o 1018.<\/span><\/p>\n

                                  R: Qu\u00e3o duro o a\u00e7o 45# pode ficar?<\/span><\/strong>
                                  R: Pode atingir cerca de 55 HRC na superf\u00edcie por t\u00eampera. O n\u00facleo de pe\u00e7as espessas, por outro lado, permanecer\u00e1 mais macio porque n\u00e3o endurece bem.<\/span><\/p>\n

                                  P: Quando devo usar o 4140 em vez do 45#?<\/span><\/strong>
                                  R: Use o 4140 quando voc\u00ea precisar que uma se\u00e7\u00e3o espessa seja muito resistente em toda a sua extens\u00e3o (t\u00eampera total) ou quando a pe\u00e7a estiver sujeita a muita tens\u00e3o ou impacto. O 4140 \u00e9 mais resistente e tenaz, mas custa mais.<\/span><\/p>\n<\/div>\n<\/div><\/div><\/div><\/div><\/div>","protected":false},"excerpt":{"rendered":"

                                  Em engenharia mec\u00e2nica, o a\u00e7o 45# \u00e9 o melhor a\u00e7o de m\u00e9dio carbono. Tamb\u00e9m \u00e9 conhecido como AISI 1045, C45 ou S45C em todo o mundo.<\/p>","protected":false},"author":1,"featured_media":9629,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[103],"tags":[],"class_list":["post-9468","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-materials-guide"],"yoast_head":"\n45# Steel (C45 \/ 1045 \/ S45C): Properties & Applications<\/title>\n<meta name=\"description\" content=\"Learn 45# steel (C45 \/ 1045 \/ S45C) chemical composition, mechanical properties, heat treatment potential, and common engineering applications.\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/www.cncmachiningshops.com\/pt\/45-steel\/\" \/>\n<meta property=\"og:locale\" content=\"pt_PT\" \/>\n<meta property=\"og:type\" content=\"article\" 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